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Civil Aviation Authority


Agricultural Aircraft Safety Review

December 2008


9 December 2008 December 2008

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Table of Contents Executive Summary ................................................................................................ 1

Chapter 1 - Introduction ......................................................................................... 5

Chapter 2 - The Lewis Report ................................................................................ 8

Chapter 3 - Regulatory Basis of Part 137 and CAM 8 ....................................... 15

Chapter 4 CAA Safety Data Review .................................................................. 27

Section 2 - Analysis by Type ............................................................................... 43

Chapter 4 - CAA Safety Data Review .................................................................. 60

Section 3 - Aircraft Comparisons. ....................................................................... 60

Chapter 5 - Unreported Incidents ........................................................................ 66

Chapter 6 - Turbine Conversions ....................................................................... 70

Chapter 7 - Certificate of Airworthiness Duration ............................................. 80

Chapter 8 - Re-use of Data Plates ....................................................................... 84

Chapter 9 - Industry Operational Issues ............................................................. 86

Chapter 10- Emerging Technologies .................................................................. 95

Chapter 11 – Airworthiness Directives Review ................................................ 102

Chapter 12 – Conclusions .................................................................................. 103

Glossary of Scientific Terms ............................................................................. 112

Annexes: .............................................................................................................. 114

A Terms of Reference for Agricultural Aircraft Safety Review ...........................

B Civil Aeronautics Manual (CAM) 8 .....................................................................

C New Zealand Civil airworthiness Requirements – Part 2.................................

D Air Transport Division – Ministry of Transport – Engineering Instruction .......................................................................................................

E FU24 Occurrences ...............................................................................................

F Cresco Occurrences ............................................................................................

G 750XL Occurrences .............................................................................................

H GA200 Occurrences.............................................................................................

I Air Tractor Occurrences ....................................................................................

J Cessna Agwagon Occurrences ..........................................................................

K Transavia PL-12 Airtruk Occurrences ...............................................................

L Zlin Z-13T Occurrences .......................................................................................

M FU24 Fin Failures and Occurrences – Summary ..............................................

N FU24 Fin Structural Comparisons ......................................................................

O Climb Performance ..............................................................................................

P Landing Gear Considerations ............................................................................



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Executive Summary The Civil Aviation Authority of New Zealand (CAA) initiated this Agricultural Aircraft Safety Review (the Review) in response to concerns expressed by CAA staff and industry stakeholders regarding the safety occurrence rate for fixed wing agricultural aircraft. Particular concerns related to Civil Aviation Rule Part 137 (Part 137), which permits an aircraft to be operated at a weight in excess of its maximum certified take-off weight (MCTOW).

The Lewis Report The CAA commissioned Bernie Lewis FRAeS, an experienced industry consultant, to prepare a report on agricultural aircraft overloading as permitted by Part 137 (the Lewis Report). The Lewis Report concluded that fixed wing agricultural operations in excess of MCTOW, as permitted by Part 137, without compensatory safety measures, affected the safety of those operations.

Following the conclusions of the Lewis Report, the Review was commissioned to examine the issue in more depth. The opportunity was also taken to widen the scope of the investigation to include a range of other issues affecting safety in agricultural aviation.

Part 137 The Review includes a detailed analysis of Part 137 and its effects. This analysis supports the Lewis Report’s principal conclusion that Part 137 lacked sufficient safety measures to compensate for the effects of operating at weights beyond MCTOW. The Review also concludes that the Lewis Report’s criticism of the way in which the United States Civil Aeronautics Manual No 8 (CAM 8) was incorporated into Part 137 is insufficient. The Lewis Report criticised the translation of CAM 8 into Part 137. The Review concludes that CAM 8 itself is an inappropriate basis for Part 137, since CAM 8 was a design certification guide, and Part 137 is an operational rule. Incorporating the intent of CAM 8 (or later derivatives) into the restricted category certification requirements of Civil Aviation Rule Part 21 (Part 21) would be an appropriate way to adopt the principle of high gross weight operation. The role of Part 137 would then be to describe agricultural operational requirements, based on aircraft issued with standard or restricted category certificates of airworthiness (COAs).

Occurrence Data Analysis The second major focus of the Review is to determine the effects of implementation of Part 137 on the safety of agricultural aircraft operations. This required a major review of the CAA’s safety occurrence data. The two main hypotheses tested were that

• The safety occurrence rate has deteriorated since 1994, and,

• The increase in accidents was linked to increased loads carried as permitted by Part 137.

A method was developed to extract the required information about safety occurrence rates from the CAA database. More than 70% of the agricultural fixed wing aircraft operating throughout the 1970-2007 study period were Pacific Aerospace Ltd FU24 variants.



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Therefore the FU24 safety occurrence data was determined to be the single most reliable indicator of the overall industry safety occurrence rate. When plotted against time, the FU24 aircraft data displayed marked increases in the rate of take-off accidents, landing gear defects and other structural problems. This appears to support the first hypothesis that the safety occurrence rate has worsened in recent years.

Testing the second hypothesis, that this increase was due to the overload as permitted by Part 137, proved to be more difficult. Most aircraft are not equipped with load measuring equipment, and there is no requirement to report the weight carried on each flight. Only the overall tonnage spread and the hours flown are reported quarterly to the CAA. However the load onboard the aircraft has a direct influence on the stress to which the undercarriage is subjected. In addition, the performance of the aircraft is inversely proportional to the load it is carrying. On this basis an assumption was made that analysis of the undercarriage failure rates, and the accidents in which aircraft performance was a factor, would enable an inference to be drawn about the loads being carried by the aircraft.

Analysis of the FU24 indicated a statistically significant increase in the rate of both take-off performance and landing gear safety occurrences coinciding with the introduction of Part 137. The Lewis Report hypothesis, that the omission of compensating safety factors from Part 137 would have a detrimental effect on safety, was shown to have occurred in practice. Furthermore, the types of safety failures that increased most markedly (undercarriage and aircraft performance accidents) were predictable considering Part 137 adopted an abbreviated version of the requirements of CAM 8. (See Chapter 3.)

The FU24 undercarriage defect rate has been used in the Review as a yardstick to measure the relative effects of various other changes affecting the aircraft, such as larger hoppers, Part 137 overload, and turbine conversions. An engineering modification to increase the robustness of the undercarriage is practicable, it would address only one of the symptoms and not the root cause. The pattern evident in the undercarriage occurrence rate also manifests itself in the fuselage and wing defects, but the frequency of these occurrences and hence the resolution of the pattern is much lower.

While the FU24 data was used as a first approximation to the fixed wing agricultural aircraft fleet, comparison of the FU24 occurrence data with other agricultural types revealed some issues that appear to be aircraft specific. For example the FU24 had 36% more undercarriage defects per flying hour than other types of agricultural aircraft. The New Zealand designed and built Cresco, derived from the FU24 but with a turbine engine and higher payload, experienced an undercarriage failure rate 4.5 times higher than other agricultural aircraft operated in New Zealand.

Turbine Conversions Turbine converted aircraft, which, after widespread conversions conducted around 2000, now comprise almost half the FU24 fleet, were also considered in detail. The converted aircraft have suffered a consistently higher rate of defects than unconverted aircraft. The reasons for this are difficult to establish conclusively, although the 50% increase in available horsepower may have contributed to the increased defect rate.

CAA approval of these conversions was conditional on the observation of existing weight and airspeed limitations to ensure there was no significant stress increase on the airframe. Operation at the existing weight was assumed to have been satisfactory since the



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development of the FU24-954 aircraft in 1979. The FU24-954 was an evolution of the original FU24 certificated in 1954, in which both engine power and weight were increased (3550lbs to 4860lbs). The ‘existing weight’ at the time of conversion was taken to be the Part 137 overload of 6366lbs, which had been sanctioned for only four years at the time the conversions were proposed.

The 31% increase that Part 137 permitted the FU24 to carry was slightly larger than for other types. However, the full 31% was probably infrequently utilised because of the limited ability of the piston engine to accelerate the fully loaded aircraft up to flying speed within the limits of a typical airstrip. Prior to conversion, few if any FU24 series aircraft would have been able to operate at weights approaching the full 31% overload.

Accordingly, the turbine conversion was approved on an unsubstantiated assumption that operation at weights up to 31% had already been proven satisfactory and that continued operation at that weight with an engine substitution would have no detrimental effect. The effect of the turbine conversion was to increase take-off and climb performance so that higher loads (up to the maximum 31% overload) could be utilised on a regular basis. The superior performance of the turbine conversion may even have enabled operation at weights beyond those permitted by Part 137.

Application of the abbreviated version of CAM 8 into Part 137 made the subsequent approval of the turbine conversion problematic, and is likely to have contributed to the two-stage increment evident in the FU24 undercarriage defect rates. In addition to undercarriage defects, the associated stresses on the turbine converted aircraft operating to the full extent of the weight increase permitted under Part 137 are likely to have led to a higher overall defect rate per flying hour for the turbine aircraft.

Industry Concerns The Review canvassed industry opinions and obtained the candid views of leading industry stakeholders, pilots, maintenance engineers, designers and manufacturers. Although the range of opinions was wide and varied, there was a general dissatisfaction with the Part 137, particularly the overload provisions.

Conclusions The principal conclusions of the Review are:

• By adopting the ‘possible weight increase’ graph from CAM 8 and using it for Part 137 without the subsequent analysis, modification and flight-testing recommended by CAM 8, the safety provisions upon which the overload graph was predicated were effectively negated.

• Overloading, as permitted by Part 137, led to an increase in the safety occurrence rate, particularly for the New Zealand-designed FU24 and Cresco aircraft. Foreign-designed aircraft operated in New Zealand, which complied with the full version of CAM 8 or its successors, have not experienced similar safety problems. Turbine converted FU24 aircraft were the worst affected aircraft. This experience is attributable to a combination of permitted overload, subsequent hopper capacity enlargement, and engine power increases.



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CAA should rewrite Part 137 in a way that recognises both the economic desirability of operating at weights above the standard category weight, and the commensurate decrease in aircraft performance and safety. This may be achieved by using the provisions of the restricted category COA to certify aircraft at the higher weight. The restricted category COA acknowledges a reduced level of safety but accepts it as suitable for the intended purpose, which, in this case, has a degree of inherent risk. The rewritten Part 137 need not consider overloading, as operations would be conducted in accordance with the limitations associated with the COA. As such, they would no longer be ‘over’ loading.



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Chapter 1 - Introduction

Background to the Review During 2004, General Aviation (GA) Group operational staff of the Civil Aviation Authority of New Zealand (CAA) and stakeholders in expressed concerns regarding the accident rate experienced in the agricultural aviation industry. In addition to a series of fatal accidents between 2001 and 2004, the CAA received reports of an increase in the number of aircraft defects.

Stakeholders also expressed concerns about the practice of rrebuilding aging aircraft and, in particular, the use of older airframes with new components and significantly more powerful engines. The practice of re-engining aircraft principally applied to Pacific Aerospace Ltd Fletcher FU24 aircraft.

The re-engined aircraft are generally more than 25 years old. Most FU24 aircraft operating in 2007 were built between 1970 and 1980: the oldest in 1967, the youngest in 1984. In some cases, the wings and sections of the fuselage have been re-skinned but the structure remains basically the same. The aircraft have given many years of service in rugged conditions. Modifications included lengthening the fuselage to keep the centre of gravity (CG) within limits because of lighter engines, and fuselage plugs are added to accommodate larger hoppers. In addition to providing the ability to carry significantly heavier loads out of the same airstrips, the increased power of the turbine engines are capable of driving the aircraft to higher speeds.

Associated with the concerns about safety were reports (many of them anecdotal) that the rate of defects and failures was increasing in areas such as the undercarriage, vertical fin and rudder structure, wing spar and engine mounts.

Another concern lay with the apparent lack of appreciation of aerodynamics and weight and balance by many agricultural pilots, in particular the need to reduce speeds, manoeuvre loadings (G) when operating at high all up weights.

CAA Safety Targets The first step in the Review was to obtain the safety performance data for the agricultural aviation industry sector. (The CAA Safety Analysis Unit (SAU) monitors the safety performance of the different sectors of the New Zealand aviation industry.) When the Review was proposed in the first quarter of 2007, the SAU’s analysis of recorded accidents and incidents in the previous 10 years indicated a significant loss of life. Expressed in economic terms for the purposes of comparison, the net cost to the nation of the lives and equipment lost in fixed wing agricultural flying was approaching $200 per flying hour.1

This was approximately twice the cost per hour of accidents in either ‘Other’ (non-airline) fixed wing commercial operations or private flying, which is usually considered a high-risk activity. Of even greater concern was the indication that the fixed wing agricultural

1 The social cost per unit of exposure is basically the annual cost of machines damaged plus the assumed costs of injury and the statistical value of human life, divided by the number of hours flown by the industry sector.



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accident rate was trending upwards, while other industry sectors, such as agricultural helicopter operations, were trending downwards.

Figure 1.1

Figure 1.2



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The two graphs above were taken from the SAU’s January 2007 Safety Targets Report. (The scales of the graphs are not identical.) The social cost of agricultural helicopter flying was much lower per flying hour than fixed wing operations. As a helicopter is usually more expensive than a fixed wing aircraft of the same all up weight, the lower ‘cost’ of helicopter operations represents a substantially smaller accident rate than the fixed wing equivalent. From the above statistics and the level of industry and public comment it was clear that a wide-ranging review of fixed wing agricultural aircraft operations was necessary.

The Review The General Manager, General Aviation, CAA initiated the Agricultural Aircraft Safety Review (the Review) in March 2007.

The purpose of the Review is to gather information, authenticate anecdotal stories, as far as is possible, and make recommendations regarding currently operated agricultural aircraft design, continuing airworthiness, maintenance and operational practices and techniques. The scope items of the Terms of Reference for the Review are reproduced in Annex 1.

Each of the scope items forms the basis of a chapter of the Review. Conclusions and recommendations relating to each of the scope items are presented at the end of each chapter and summarised in Chapter 12.



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Chapter 2 - The Lewis Report Scope item 1: “Review the Bernie Lewis report commissioned and completed in 2005 and review the resultant recommendations.”

Introduction In August 2005, the Manager, Rotary Wing/Agricultural, CAA commissioned Bernie Lewis FRAeS, an experienced industry consultant, to report on the current Rule regarding aircraft overloading, the industry’s interpretation of the Rule and to make recommendations as required. (The result report is referred to as the ‘Lewis Report’.) The Civil Aviation Rule in question is Part 137 – Agricultural Aircraft Operation. Two provisions of Part 137 are of particular importance. These are Maximum take-off weight (137.103) and Overload Weight Determination (Appendix B).

Lewis Report Content The CAA considers the Lewis Report to be well researched with sound underpinning engineering information. Anecdotal evidence gathered for the Review generally supports the observations of the Lewis Report.

The Lewis Report primarily reviews agricultural aircraft overloading as permitted by 137.103(a). In its conclusions, the Lewis Report criticises the CAA for the way it has regulated the operation of agricultural aircraft, in particular, the omission from Part 137 of the 6% climb gradient performance limited take-off weight (PLTOW) that was required in the pre-1994 New Zealand regulatory system.

After discussing a number of issues that have arisen since Part 137 raised the permissible overload from 12% to 31%, the Lewis Report recommends re-introducing safety factors not included in Part 137.

Review of Lewis Report Recommendations

Recommendation 1: “The wording of Part 137 Appendix B – Overload Weight Determination be written to remove the ambiguity of the wording “original aeroplane load limit factor and provide warning to reduce airspeed by W (certified gross weight)/W (new gross weight) x Vne.”

2

The term “original aeroplane load factor”, which was adopted from the United States’ Civil Aeronautics Manual No 8 (CAM 8), is ambiguous when applied to the Cresco and FU24 series because different load factors are listed in their flight manuals. One of these (the lowest) is for flight with flaps down, and so can be disregarded, leaving a choice of the normal flight load factor of 3.56 g or the restricted category load factor of 3.0 g. 3.56 g is the normal load factor for aircraft certified to the United States’ Federal Aviation Rule (FAR) 23, such as the Cresco.

2 Vno = Velocity Normal Operations. Va (Velocity Maximum Acceleration) is commonly referred to as ‘manoeuvring speed’ as this is the speed at which the aircraft is capable of generating its maximum manoeuvring load factor (acceleration at 90 degrees to the direction of travel). At speeds above Va, control movements must be made carefully to avoid excessive stress on the airframe.



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The reduced load factor in the New Zealand restricted (agricultural) category is derived from Leaflet C.10-4 that constituted CAA policy on agricultural aircraft certification prior to the current rule system. Both the FU24 and Cresco were designed before Part 137 was introduced, and, according to the policy at the time, the manufacturer made provision for an ‘Agricultural Overload’ of approximately 12%. This weight is listed in the flight manual as the ‘restricted category weight’. At the restricted category weight, the reduced load factor on which it was predicated must be observed. This is the origin of the two weights and two load factors in the flight manual of New Zealand’s two most popular agricultural aircraft.

From the above, the Lewis Report’s conclusion that the rule is ambiguous appears to be correct. However, the issue of which load factors to use is probably overshadowed by other problems with the Part 137 Appendix B graph, which is discussed in Chapter 4.

The Lewis Report recommends that that an airspeed reduction be applied to aircraft operating in accordance with Part 137 Appendix B. This recommendation is reasonable if certification in accordance with CAM 8 were to be pursued. (CAM 8 details the reasons for reducing Vno to Va .)

The FU24-954’s Vno is restricted to 114 kts when operating in the restricted category in the United States.

Recommendation 2: “Aircraft should also be checked for handling, (as per CAM 8) and meet a minimum sustained rate of climb of 500 ft/min. This should be an annual certification in the logbook.”

Recommendation 3: “An immediate Directive be issued warning operators of the need to reduce airspeed when operating at their maximum overload and to check that their aircraft can sustain a 500 ft/min rate of climb.”

Recommendation 4: “I strongly recommend that a graph showing the speed reduction be included in the overload allowed by Part 137. It is a far better way of drawing a pilot’s attention to the reduction, rather than have him work it out for himself…Manoeuvring speeds should also be reduced accordingly.”

These recommendations relate to adding measures to Part 137 to reduce ambiguity and re-introducing provisions of CAM 8. These recommendations have some support in industry in the form of the production of an Advisory Circular (AC), explaining how to account for the performance reductions that can be expected at the overload weight. However, while the Lewis Report’s conclusions in this regard are valid and reasonably practical, they are essentially attempting to compensate for the fact that the graph from CAM 8 is being used in a way it was not intended to be. (This issue is discussed further in Chapter 4.) Implementation of the first four recommendations of the Lewis Report would provide more information to the pilot in those situations where 137.107 permits operations beyond the limits of the flight manual. However, as the aircraft would still be operated at the Part 137 Appendix B weights, it would still likely be subjected to loads above its certified design condition, with a commensurate increase in defects. The CAA supports the intent of these recommendations, but does not support their substance. .



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Recommendation 5: “All loaders should be fitted with a weight and load counter that could provide a print out at the end of the day. This could also act as a check for overloading. A load measuring device similar to that in the Zlin, should be compulsory in all topdressing aircraft.”

The CAA supports this recommendation as it would introduce greater certainty into the operation of agricultural aircraft as well as providing a means for CAA audit (in a similar way to baggage/freight loading manifests in Part 119 operations). Many of the loaders in service are fitted with load measuring devices – either calibrated hydraulic gauges or the better digital load cell devices. Operators have historically opposed mandatory use of these devices on the grounds of their low reliability in service. It is likely that this objection is overstated. F fertiliser is billed by the ton delivered to the farm gate; this implies that a party in the supply chain has some reliable and accurate weighing equipment. (This comment was provided by an industry response and is detailed in Chapter 10.)

Recommendation 6 “Companies should be given a specific time in which to fit tamper/proof hour meters, when they become available.”

The CAA and industry stakeholders generally accept the principle of tamper-proof hour meters being fitted to agricultural aircraft once suitable technology has been developed. (Chapter 11 discusses Time in Service Recorders in more detail and whether they are necessary for fixed wing agricultural aircraft.)

Recommendation 7: “The fatigue life of old aircraft, when fitted with turbine engines should be reassessed.”

This recommendation is controversial. Two views on this issue are summarised below.

No Reassessment of Fatigue Lives: On the face of it, there is no need to reassess its fatigue life if a modified aircraft is operated within the existing flight envelope (i.e. same weights and speeds) and the power increase is ‘small’. The underpinning rationale is, if the aircraft travels through the air at much the same speed, with the same weight on board, with only small power increase such that it cannot sustain high load factor manoeuvres for appreciably longer than the original version, then the use of a turbine engine will not affect the integrity of the airframe.

The other factor that complicates re-assessing the fatigue life of early model aircraft is that some were designed before fatigue assessments were a certification requirement. For these early design aircraft, assessment of the fatigue life would have to be done from scratch, rather than just recalculated. This would require access to the original aircraft design data. For older aircraft this is hard to obtain and difficult to work with for example, hand written calculations. It is also difficult for an applicant, who is not the type certificate holder, to obtain permission to use this data.

It is self-evident that aircraft for which a fatigue assessment was not a certification requirement may experience metal fatigue. In fact their design predates the rapid increase in understanding of aircraft structural fatigue that took place in the early 1960s following



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the De Havilland Comet accidents. The state of the art regarding design for fatigue resistance was not high at the time these aircraft were designed.

In lieu of an assessment and prediction of the structural fatigue life, regular inspections are carried out to detect and correct any failures before they can become catastrophic.

These planes are expected to be operated at relatively low stress levels in normal service, which, to some extent, negates the need for a detailed fatigue assessment.

If the loads on the aircraft remain the same after re-engining (speed, weight, power), and the existing maintenance requirements have been adequate (no major failures recorded), arguably there is no need to perform a fatigue life re-assessment.

Reassessment of Fatigue Lives: In September 1993, the United States’ Federal Aviation Authority (FAA) published Advisory Circular AC 23-14 (Type Certification Basis for Conversion from Reciprocating Engine to Turbine-Powered Part 23 Airplanes). AC 23-14 notes that, regardless of the power increase, turbine engine and propeller combinations may introduce a different vibration spectrum from that previously experienced by a piston powered airframe, and recommends an investigation of the horizontal stabiliser.

In addition to unexpected vibratory responses introduced by the change of engine and propeller, where there is a moderate power increase or increase in utilisation, the frequency with which damaging loads are encountered may be increased. There is evidence that this has occurred on the FU24 turbine conversions. (See Chapter 5 Section 2. The effect of changes in the aircraft load spectrum are discussed more fully in Chapter 7.)

In general, a turbine engine is fitted to an existing airframe either to increase performance beyond that achievable with a piston engines (for example the Lancair IV-P), or to allow the aircraft to continue in revenue service after it has become uneconomic to continue operating with a piston engine (for example the Convair 580). Therefore, without the turbine engine, the operator would most likely retire the aircraft; a turbine conversion permits a significant increase in service life.

In the first case, increased loads on the airframe, which will require reassessment, are likely. In the second case, the continued operation of the airframe will ensure that fatigue damage continues to accrue. If the existing flight envelope and load spectrum is preserved, fatigue damage should continue to accumulate at the same rate. However, keeping the airframe in service increases the number of defects that can be expected. Therefore, it is reasonable at the time of conversion to assess the types service history, and address any concerns regarding the re-engined aircraft. A revised inspection program is a common way to achieve this.

If the assessment of the airframe type’s service history reveals the occurrence of fatigue cracks that have not been adequately captured by the maintenance and inspection program, an assessment of the designs fatigue life may be necessary. In practice, a purely analytical approach to calculating fatigue life is notoriously difficult, and the predicted life varies considerably depending on assumptions made. It may be quicker, simpler and more reliable to design strengthening modifications for critical areas of the aircraft.



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Conclusion – Fatigue Life Assessments Requiring the complete re-assessment of airframe fatigue lives when they are fitted with turbine engines would probably increase the safety of the modified aircraft, but in many cases would be impracticable. Nonetheless, FAA AC 23-14 recommends, in the case of turbine engine conversions, if engine power, airspeed limits, propeller rotational speed or number of propeller blades are changed, the applicant should provide substantiating data showing that the vibratory response of the horizontal tail assembly to the propeller slipstream environment will not result in fatigue failures.3 A fatigue assessment of the horizontal tail in accordance with FAA AC 23-14 would be more practicable than an entire airframe fatigue life re-assessment. In addition to a partial fatigue assessment of the horizontal stabiliser, it would be prudent to review the airframe type’s service history, and review the overall design for critical features.4 This may indicate other areas where fatigue re-assessments are necessary. Any ‘Achilles heels’ in the existing design should be catered for by reducing the maintenance interval of the modified aircraft or the addition of reinforcing design features such as straps or doublers in the areas of concern. (Chapter 7 discuses the effect of turbine conversion on existing airframes in more detail including the requirement for a ‘changed product’ rule.)

Recommendation 8: “Undercarriage legs are not adequate. Investigation should be directed towards dual wheels, larger wheels, and/or sturdier oleos.”

The Lewis Report notes an increase in undercarriage failures particularly amongst the FU24 and Cresco aircraft, and recommends an engineering investigation of the cause, and subsequent modification to reinforce the gear. (Chapter 5 examines the FU24 and Cresco undercarriage rates in detail, and verifies this observation of the Lewis Report.) To complete an engineering assessment of the undercarriage, it is essential to know the weight at which the undercarriage is intended to operate. Under a CAM 8 Appendix A certification effort, the weight selected from the wing load curve Figure 7-2 would be carried over into the undercarriage engineering analysis.

Engineering Assessment of Undercarriage Loads. The usual design case for undercarriage on small to medium sized aircraft is assumed to be the ‘hard landing case’, where the aircraft is set up for a landing but the pilot does not arrest the rate of descent fully. FAR 23.473, for example, provides a means of simulating the load that could be expected under these circumstances. For regular private single engine aircraft, this is accepted as the highest load that it is likely to carry once or twice in the aircraft’s lifetime, and equates to completing a normal 600 fpm approach without arresting the rate of descent just prior touchdown. For small aircraft, the maximum landing weight is usually assumed to be the maximum take-off weight, but may be no less than 95% of the maximum take-off weight.5

3 The horizontal stabiliser usually manifests a higher aspect ratio than the vertical stabiliser, and hence is more critical for vibration, depending on construction.

4 An assessment of the aircraft type’s service history requires access to good occurrence data. The present limitations to accessing this data are discussed in Section 3

5 FAR 23.473(b)



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As take-offs are generally a smooth acceleration away from the earth, the loads generated during take-off are usually much less than those generated in a hard landing, if the weight at landing is no less than 95% of the take-off weight. The hard landing is such an infrequent event for normal aircraft that design for static strength under this condition usually provides sufficient margin against fatigue damage during the thousands of normal landings. However, for an agricultural aircraft the landing weight could be as low as 50% of the take-off weight. The landing speed of an unloaded FU24 is 55 knots from which it decelerates rapidly. Its take-off rotation speed could be as high as 70 knots. Acceleration to 70 knots is not rapid and, during those seconds, the gear is carrying a high load at higher speed across a much rougher airstrip than normal. Under these circumstances, the standard design case for the undercarriage may not be conservative. If the standard hard landing design criterion is used, at what weight should it be calculated? The only conservative way to cover the ‘rough strip take off at agricultural weight’ case is to analyse the landing gear for hard landing at agricultural weight, or else develop a more rational analysis of the loads during take-off at agricultural weights. (The design considerations for landing gear, including the effect of uphill landings are explored further in Annex P.)

Recommendation 9: “The Industry Guidelines on Farm Airstrips and Associated Fertiliser Cartage, Storage and Application, should be implemented as soon as possible.”

This recommendation was implemented in December 2006 by the publication of the booklet Safety Guidelines Farm Airstrips and Associated Fertiliser Cartage, Storage and Application, a joint venture between the CAA and the Department of Labour,. The airstrip surface condition assessment in this publication suggests a motor vehicle should be able to be driven comfortably along the strip at 80 kph. By comparison, aircraft take-off speeds of 55-65 knots equate to 102-120 kph. The previously mentioned design case for undercarriage take-off loads should take into account this method of strip condition assessment.

Conclusions on the Lewis Report

Conclusion 2.1 The Lewis Report provides a detailed assessment of certain issues faced by agricultural aircraft operating under Part 137. The opinions expressed in the Lewis Report are plausible and the aerodynamics calculations are correct.

Conclusion 2.2 The Review supports the principal conclusion of the Lewis Report that Part 137 does not provide an adequate basis for operations beyond MCTOW.

Conclusion 2.3 The Lewis Report’s recommendations (1-4) on the CAA providing further guidance material to detail an aircraft’s performance at the agricultural weight may improve safety but would not address the increasing equipment failure rate that is likely to be experienced when the aircraft is operated outside of its design envelope. The provision of further guidance material from CAM 8 is unlikely to be useful, firstly, because CAM 8 was not



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intended to be an operational rule, and, secondly, the FU24 and Cresco were not certified to CAM 8. .

Conclusion 2.4 The Review supports recommendations 5 and 6 of the Lewis Report regarding loading bucket weight devices and mandatory TSRs.

Conclusion 2.5 The Review conditionally supports recommendation 7 of the Lewis Report regarding fatigue assessments of aircraft refitted with turbine engines. (FAA AC 23-14 supports the re-assessment of horizontal stabiliser fatigue.)

Turbine conversions represent a considerable investment in an old airframe, and operators expect such conversions to substantially extend the economic life of an aircraft. As such, re-engined aircraft are, in effect, a changed product. New Zealand currently has no clear ‘changed product rule’, but the need for one has been noted.

Conclusion 2.6 The Review supports recommendation 8 of the Lewis Report regarding engineering assessment of the undercarriage. The undercarriage should be assessed as part of a co-ordinated certification process at the nominated agricultural weight. To complete the engineering assessment of the undercarriage, a CAA policy on acceptable agricultural weight should be determined.

Conclusion 2.7 Recommendation 9 of the Lewis Report regarding publication of strip guidelines has been adopted with effect from December 2006.

Conclusion 2.8 Operation at weights beyond an aircraft’s original MCTOW is feasible when an engineering analysis establishes that sufficient capability exists in the affected structural components, and satisfactory flight characteristics are demonstrated. If operations at high weights for agricultural purposes are to continue, there is a requirement for:

a) A suitable certification basis for the engineering assessments that takes into account the nature of agricultural operations, b) A suitable set of operational parameters including, but not limited to, climb gradient, take-off performance, and stalling speed.



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Chapter 3 - Regulatory Basis of Part 137 and CAM 8 Scope item 2: “Review all New Zealand Civil Aviation Authority documented safety occurrences, findings and open actions relating to agricultural aircraft.”

Introduction Following the Lewis Report which criticised aspects of Part 137, the Agricultural Aircraft Safety Review (the Review was commissioned in March 2007. The primary aim of the Review was to review the safety performance of the fixed wing agricultural industry sector and in doing so quantify the criticisms voiced in the Lewis Report. If the Lewis Report highlighted some of the problems faced by the agricultural aviation industry, the AASR was essentially tasked with answering the question ‘ just how big is the problem?’

Given that the Lewis Report was essentially a review of operations conducted under Part 137 and the Review was a more detailed investigation of the same industry sector, an understanding of the regulatory basis for fixed wing agricultural operations is essential to comprehension of the AASR and its conclusions. To provide that information this chapter contains the following sections.

• A discussion of Rule Part 137 and in particular the provisions within Part 137 for operation beyond the aircraft’s maximum certified take-off weight (MCTOW).

• The New Zealand regulations that preceded Part 137.

• An explanation of certification in the Standard and Restricted Categories.

• A detailed analysis of Civil Aeronautics Manual 8(CAM 8). Elements of this document, which was published by the United States Civil Aeronautics Administration (USCAA), the forerunner to the Federal Aviation Administration (FAA), are effectively incorporated in Part 137.

Part 137 Agricultural operations are governed by Part 137. Excerpts from the rule are listed below.

Description Part 137 prescribes rules, that are additional to and exceptions from the general operating and flight rules prescribed in Part 91, for pilots performing or being trained to perform agricultural aircraft operations. Part 137 also prescribes additional instrument and equipment requirements for aircraft conducting agricultural aircraft operations, as well as requirements for the certification and operation of persons performing commercial agricultural aircraft operations.

The New Zealand Civil Aviation rule system is hierarchical, and many of the rule parts are complementary. Part137 must be read in conjunction with the preceding rules, in particular the General Operating Rule Part 91. Part 137 prescribes rules additional to and exceptions from Part 91. The exception to Part 91 concerning take-off weight is detailed in section 137.103.



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137.103 Maximum take-off weight (a) Notwithstanding Part 91 and subject to paragraph (b), a pilot performing, or being trained to perform, an agricultural aircraft operation in an aeroplane must not take-off at a weight greater than the MCTOW prescribed in the aeroplane’s flight manual unless—

(1) the pilot complies with the procedures listed in Appendix B; and

(2) the aeroplane is equipped with a jettison system that, in accordance with D.5, is capable of discharging not less than 80 percent of the aeroplane’s maximum hopper load within five seconds of the pilot initiating the jettison action.

(b) Where there is a third party risk as defined in Appendix A, the pilot must determine the maximum take-off weight in accordance with 137.107 and 137.109.

In short, Part 137.103(a) provides an exemption to the requirement of the general flight rules Part 91 that the aircraft must not be operated at a weight greater than its maximum certified take-off weight (MCTOW). Notwithstanding the Part 91 MCTOW, pilots may operate the aircraft at any weight up to the weight shown on the graph in Appendix B to Part 137 provided there is no third party risk.

137.105 Take-off distance and flight path — no third party risk A pilot performing, or being trained to perform, an agricultural aircraft operation in an aeroplane where there is no third party risk as defined in Appendix A is not required to comply with the following:

(1) the take-off distance specified in the aeroplane flight manual;

(2) the take-off flight path gradient specified in the aeroplane flight manual.

Part 137.105 states that while operating at this overload weight the pilot is not required to comply with the aircraft flight manual requirements for available take-off distance and obstacle free climb gradient. This rule was required because at the overload weight, the aircraft will not achieve the performance on which the flight manual figures are predicated. Observing the flight manual requirement to have a strip length of at least 400m is not possible if the aircraft will actually require 450m to get airborne. At the Appendix B overload weight the aircraft will require more strip length and lower obstacles on the climb-out path. How much longer and how much lower is left to the pilot to determine.

No data for the aircraft performance at the Appendix B load is provided, so the distance below the normal take-off path that the overloaded aircraft will fly is not known. This is reason that the load dumping provisions of 137.103(a) 2 are included in the rule; when it becomes apparent to the pilot that he may not clear the trees he has the ability to dump the load and regain some aircraft performance.

The Lewis Report reviewed these two particular sections of Part 137

Predecessor to Part 137 When considering the content of Part 137 it is useful to compare it to the previous CAA requirements for agricultural aircraft, which were New Zealand Civil Airworthiness



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Requirements Part II leaflet C.10-1 through C.10-10. Copies of these leaflets are included as Annex C. Leaflet C.10-7 details the aircraft handling and performance requirements and requires that the aircraft be capable of achieving a climb gradient after take-off of at least 6%.6 It also requires take-off distances to be calculated for the agricultural weight. The maximum agricultural weight is specified in Leaflet C.10-1 using a formula that takes account of the original aircraft maximum design manoeuvring load factor (G limit). For the FU24-950, the agricultural weight per Leaflet C.10-1 is 5430lbs, a 12% increase over the design weight of 4860lbs. This weight is shown in the flight manual in the ‘Limitations’ section. Take-off and climb performance graphs up to and including the agricultural weight are also included in the flight manual. These graphs are still applicable under Part 137, but do not cover the range from 12% out to 31%.

The CAA policy relating to the certification of agricultural aircraft in accordance with the Leaflets was amplified by Engineering Instruction EI-23, which is attached as Annex D. EI-23 notes that where an aircraft has been certificated in the United States with an agricultural category weight, the limitations imposed by the FAA are to be observed. EI-23 also sets out requirements for non-flying crew seats and requires the provision of information to the pilot on the weights, altitudes and temperatures at which the 6% climb gradient requirement can be met. By comparison Part 137 does not specify a minimum climb performance or require the provision of performance data for operations at weights above MCTOW.

Certification in Standard and Restricted Categories As there are no exceptions or additions in Part 137 concerning Certificates of Airworthiness (CA), aircraft operating under Part 137 must have a CA issued in accordance with Rule Part 21 Subpart H. While it is technically possible for an aircraft with dispensing equipment to be issued with a standard category CA, in practice 21.177 © requires that the aircraft be issued with only a restricted category CA if;

‘…the aircraft is internally equipped for dispensing substances on an agricultural aircraft operation and the extent of the internal equipment makes the aircraft inappropriate for use in an air transport operation.

Although 21.177 (b) allows an aircraft to be issued with a dual category COA (standard and restricted) where the aircraft can be easily reconfigured, almost all fixed wing aircraft conducting agricultural operation do so while holding a Restricted category COA. As operations conducted under Part 137 are essentially performed by aircraft with restricted category COA, at this point it is worth clarifying the concept of restricted category airworthiness certification. This is also important for the discussion of the USCAA document CAM 8 as it provided guidance in the certification of aircraft in the restricted category as opposed to the standard category. The following is intended to clarify the concepts of standard and restricted aircraft certification.

6 1:17 or 3.4 degrees or slightly under 500 fpm for the FU24 at 80 knots best ROC speed.



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Standard and Restricted Certification – An Analogy Certification of an aircraft can be compared with the design of a building to meet the New Zealand building codes. Similar to building codes, the aircraft ‘certification standards’ are a list of requirements that the aircraft design must meet such as strength, ease of operation and even the colours of instrument markings. Like building codes they provide a certain amount of commonality between designs as well as ensuring a minimum level of safety. The ‘certification basis’ refers to the particular version of the ‘certification standard’ that was used for a given aircraft design. Like building codes, the certifications standards are constantly updated and generally become more stringent as time pass, and accidents occur.

To be eligible for a standard category CA, the aircraft design has to meet all of the requirements of the certification basis in effect at the time the design is certified. Only aircraft with a Standard category C A are eligible to carry fare-paying passengers (Air Transport Operations). If the aircraft meets most but not all of the certification requirements, it may be eligible for a Restricted category C A. This certificate is issued with some restrictions such as ‘Essential crew only” or “Not for flight over built-up areas”. Restricted Category aircraft are not eligible for Air Transport operations but may conduct private and certain commercial operations

As an illustration, consider the design of stairs in buildings. To meet the building code requirements the stairs in New Zealand houses must conform to a certain set of guidelines that require them to be neither too steep nor too flat. This constrains the design of staircases within certain limits and ensures that most steps encountered will have similar rise and tread dimension. These dimensions have been found to be the easiest to walk up and thus ensure the greatest safety for people of different ages and abilities. It is of course possible for able-bodied people to climb steps almost as steep as a ladder. While the building code for domestic dwellings allows little latitude, in an industrial building where access is limited to authorised staff, a much steeper set of stairs may be permitted (although usually fitted with a cautionary sign).

Normal category aircraft are required to have as stalling speed no higher than 61 knots7 to ensure they are easy to land by pilots of average skill. An aircraft with a higher stall speed could be approved in the restricted category based on the requirement experienced pilots fly it. In this way the certification of an aircraft in the restricted category is analogous to the approval of steep steps in an industrial building; the design does not meet all the requirements of the standard (domestic) category and may be more difficult to use, but it is not unsafe for its intended special purpose.

Civil Aeronautics Manual 8

Background to CAM 8 Civil Aeronautics Manual 8 (CAM 8) was a document published by USCAA on 11 October 1950. USCAA was the predecessor of the FAA). CAM 8 contained the policies and interpretations of the Administrator of Civil Aeronautics (ACA) to Part 8 of the regulations of the Civil Aeronautics Board. At that time Regulation Part 8 was new, and a significant departure from previous restricted category airworthiness requirements. Part 8

7 FAR 23.49 c) 1, single engine aircraft



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was the regulation governing the issue of type certificates and airworthiness certificates in the restricted category.

The new Part 8 departed from the previous requirements, which required an equivalent level of safety as a passenger-carrying aircraft. The ACA accepted that for special purposes, in this case agricultural, compliance with restricted category requirements could be simplified, and the operating limitations could be tailored to the purpose of the operation. The ACA also accepted that for certain special purpose operations, such as fire fighting and crop dusting, an equivalent level of safety to passenger carrying aircraft could not be established, as the entire operation was inherently more dangerous. Although the removal of the equivalent level of safety criteria made certification of agricultural aircraft more practicable there was still a requirement that good engineering practice be maintained, and that no feature of the design or modification would render the aircraft unsafe. The idea behind Part 8 was to provide the greatest flexibility and minimum burden on the operator, consistent with public safety.8

CAM 8 was intended to provide guidance in the interpretation of the Regulations. The document has an unusual layout in that the Regulation is set out with numbers 8.0 through 8.34. Each regulation is followed by the ACA’s interpretive materials, which are identified by consecutive dash numbers appended to the regulation numbers. Thus section 8.0-2 is the second of the Administrators guidelines to interpreting Regulation 8.0.

Analysis of CAM 8 CAM 8 is a certification standard, not an operational rule. It was intended for use by FAA staff certifying aircraft in the restricted category, and was also available to applicants for restricted category certificates. CAM 8 sections 8.0 through 8.34 describe the administrative procedures for issuing a type certificate to aircraft in the restricted category. CAM 8 considers aircraft eligible for a restricted category type certificate to fall into one of the following classifications. (CAM 8 section 8.10 refers)

1) New aircraft designs not previously type certified, but shown by the applicant to comply with all those requirements of the any other (i.e. standard) category, except those which the Administrator find inappropriate for the special purpose.

2) Ex US or foreign Military aircraft whether or not such aircraft have previously been issued a type certificate.

3) An aircraft modified from a design previously certificated in another (standard) category.

For aircraft designed after 11 October 1950, and applying for a type certificate in the restricted category without first obtaining standard category certificate (classification 1 above), certification in the restricted category is to be carried out as detailed in 8.10-1. This section requires certification to the requirements of one of the standard categories, LESS those requirements deemed inappropriate. Appendix B to CAM 8 may be used as a guide to selecting the appropriate requirements, In effect CAM 8 Appendix B provides a cut down version of CAR 3 and could be considered the minimum standard for certification of new agricultural aircraft (in 1950). Appendix B contains the same basic requirements of 8 Annex B contains a brief outline of CAM 8 Prepared by CAA Rules Specialist P Elton



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CAR 3 with relief in some area (such as stall speed and climb performance) and tighter requirements in other areas such as crew restraints. CAM 8 Appendix B does not include the wing load curve; instead it requires the new wing design to be fully substantiated for the intended restricted category operating weight,

Aircraft in classifications 2 and 3 (the ex-military and modified standard category aircraft) were assumed to have been already proven to a reasonable standard of airworthiness. These aircraft could apply for a restricted category certificate considering only the changes made to them in their new special purpose role. (Section 8.10-3 refers). For these aircraft, the certification process to be used is described in 8.10-3 which refers to 8.10-4 and thus Appendix A to CAM 8.

Requirements Of CAM 8 Appendix A CAM 8 Appendix A provides guidance on how to undertake the conversion of an existing aircraft to a restricted category agricultural aircraft. Section 1.22 of CAM 8 Appendix A provide the following list of steps to address in the conversion of an aircraft, and indicate the way CAM 8 Appendix A was intended to be used by the Administrator.

1.22 Suggested Procedure for the Conversion of a Personal type to an Agricultural type

(a) Determine what is required.

(1) Dusting equipment installation. (2) Spray equipment installation. (3) Combination of (1) and (2) (4) Pay load (hopper or tank capacity) (5) Engine Change (6) Increase in gross weight (7) Change in flight characteristics (8) Modification of landing gear (9) Change in geometric configuration of fuselage

(b) Determine design of hopper or spray tank (c) Determine design of hopper venturi or spray boom, (d) Determine structural modification necessary for hopper or spray tank

installation and how to accomplish (e) Determine power source for pressure pumps or agitators, (wind or engine).

(f) Determine location and installation of agitators or power pump unit. (g) Determine location and installation of spray booms. (h) Determine materials to be used. (i) Check weight change. (j) Make preliminary weight and balance check. (k) Check the alteration for flight characteristics. (l) Check the conversion for cost.

This list is followed by sections 2.0 though 9.1 which provide guidance in making the determinations listed above. Section 7.0 discussed weight and balance and Figure 7-1 entitled ‘Possible Weight Increases’ is provided to assist with the selection of an increase in gross weight per step (a)(6) above. Note that once the new weight based on the wings



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reserve strength has been selected from the graph, the engineering assessment of the rest of the aircraft continues in accordance with the list in section 1.22 of CAM 8 Appendix A.

One way to understand CAM 8 figure 7-1 is to consider just the bolts that attach the wing to the fuselage. In level flight, the wings are developing a lift force that equals the weight of the aircraft. This force is transmitted from the wings to the fuselage via the attachment bolts. To manoeuvre the aircraft, the wings must develop a force larger than the aircraft’s weight to accelerate it in the desired direction. The magnitude of this force depends on the desired rate of acceleration. For aircraft design purposes this manoeuvring acceleration is taken as value between 3.5G, which is uncomfortable, and 6G which is close to the limit of consciousness for most people. Accordingly the wing attachment bolts and all the wing components, are sized so that during a sudden manoeuvre, the wings can develop a force of three or more times the aircraft’s weight and transfer that force into the fuselage.

Given that wing attachment bolts have been designed to take a force 3.5 or even 6 times greater than the weight of the entire aircraft, Figure 7-1 proposes that this reserve strength for manoeuvring, which is unused in straight and level flight, be traded for the ability to carry a heavier load. Essentially, the wing attachment bolts won’t know the difference between a hard turn at moderate weight or a moderate turn at a high weight.

Section 7 goes on to detail the assessment of the effect of the new gross weight on landing gear and the flight characteristics. Section 7.10 mentions the need to assess changes in C of G position as it may increase the load distributions between main wheels and nose or tail wheels. This may also occur when the aircraft’s gross weight is retained, but the C of G for that weight is altered. An example would be the fitting of a hopper into the forward bomb bay of a torpedo bomber. While the overall weight is the same, it is not suspended evenly from the front and rear hangers as a load of torpedoes was, so the C of G and load distribution changes. The case where the CG remains the same but the gross weight is increased is not mentioned in Appendix A, it was considered too obvious to require comment, in what is essentially a guide and not a complete certification basis.

Manoeuvring Speed Limitation CAM 8 Appendix A Figure 7-1 shows how the manoeuvring load factor built into an aircraft, already certified in the standard category, can be traded for higher weight lifting ability when operated in the restricted category. The obvious caveat to this is that the manoeuvring load factor (the ability to turn sharply and ‘pull G’) must be reduced in restricted category operations.

The simplest way to do this is to restrict the maximum flying speed to Va. At this moderate speed, to generate significant G forces the wings’ angle of attack must be increased substantially. However the wing stalls at a maximum angle of attack regardless of airspeed. When the wing reached that angle (12-15 degrees depending on airfoil section) it stalls and lift decreases. The lift developed (and hence load it applies) just prior to stalling is proportional to the airspeed at that particular moment. Hence restricting Va limits the lift and thus manoeuvring load factor (G) that can be applied. It can be appreciated that restricting the speed at which the aircraft can be manoeuvred is a simpler method of limiting loads on the airframe than requiring the pilot to monitor a G meter during



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manoeuvres.9 This reduction in manoeuvring and pull-up speeds is detailed in section 7.11 of CAM 8 Appendix A.

Part 137 does not require any reduction in manoeuvring speed Va or the maximum permissible speed Vne, although it cautions the pilot to avoid ‘severe manoeuvres’

CAM 8 section 8.10-3(e) specifies a flight characteristics and handling check. Appendix A section 9.0 provides a guide to the reduction in climb performance that can be expected. Section 9.02 notes there are two sources of reduction in climb performance, the extra weight, and the additional drag of the external dispensing equipment. Testing of aircraft with and without dispensing equipment showed the converted aircraft experienced a climb reduction of 15-30%. The addition of increased weight further decreased the climb performance and Figure 9-1 “shows the approximate maximum rates of climb available at various weights for several typical models used in agricultural operations”. The results showed climb reduction of 45-75%, at a weight of 20% above that which was used as a basis for the analysis. Figure 9-1 was complied to list the climb performance of some common light aircraft types at the time and reduce the need for flight-testing of those types. For new aircraft types CAM 8 Appendix B section .122 specifies a minimum rate of climb of 8Vs or 300 feet per minute whichever is greater10.

Summary of CAM 8 Appendix A CAM 8 Appendix A was intended to be used for the certification of existing standard category (or ex-Military) aircraft in the restricted category after their conversion to agricultural aircraft types.11 This was done to ease the burden on the applicant who was often not the original manufacturer. This route to certification required basic flight-testing in the modified (increased weight) configuration but only as a check, as the basic aircraft was assumed to have been extensively flight tested in its previous role.

The curve in CAM 8 provides a guide to the modifying engineer and the certifying authority as to how much reserve capacity the wing has. CAM 8 notes that the curve represents a limit that should be approached with caution, not used as guarantee of safe operation. The curve considers only the wing load capability and the rest of CAM 8 Appendix A details other structural considerations that need to be made during the conversion from standard to restricted category operations.

New aircraft not previously issued with a type certificate that applies for a type certificate in the restricted category are required to be type certificated in accordance with CAM 8 Appendix B.

9 CAM 8 section 8.30-1 authorises the administrator to prescribe limitations such as Vne reduction to Va

10 Rate of Climb (feet/min) = Stalling Speed (mph) x 8. For example at the maximum permissible stalling speed of 70mph (App B .121), minimum ROC = 560 fpm.

11 CAM 8 section 8.10-3 and 8.10-4 refer.



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Certification of the FU24-950 – Comparison of Regulatory Requirements The commonly used Pacific Aerospace Ltd FU24-950 provides an illustration of the different way in which certification of aircraft for agricultural operations has been handled between the New Zealand and United States systems..

The FU24-950 and 954 were designed as an update of the FU24 to include the 400HP eight cylinder Lycoming engine and were type certified in New Zealand on 11 December 1970. (New Zealand type certificate data sheet (TCDS) A3-Part 2 refers.) The certification basis was the former FAA standard Civil Aviation Rule (CAR) 3 dated 1956, carried over from the previous FU24 model. MCTOW was 4859 lbs in the standard category, and 5430lbs in the ‘Agricultural’ Category. The agricultural weight represents a 12% increase over the standard category takeoff weight and was calculated in accordance with Civil Aviation Department leaflet C.10-7

In 1978 the then New Zealand Aerospace Industries Ltd was granted a United States type certificate for the FU24-954. (FAA type certificate A9PC refers.) The certification basis was FAR 21.29 in the normal category, FAR 21.25 in the restricted category, which included FAR 23 effective Feb 1965 (amendment 23-21). Compliance was also shown with the FAR 36 noise requirements. Possibly to comply with the Noise Control Act 1972 (required by FAR 36) the maximum all up weight was limited to 4600lbs in both normal and restricted category operations.12 In restricted category operations the aircraft speed was limited to 114 knots, which was the maximum structural cruising speed (Vno or essentially the same as Va for this aircraft) A significant change between CAR 3 (May 1956) and FAR 23 amendment 23-21 (1965) was the introduction of a requirement to assess the airframe fatigue life. Accordingly the FU24-950/954 main spar was limited to 7200 flight hours, with the option to extend spar life with further approval by the FAA. The FU24-950/954 was not certified to CAM 8 in either the New Zealand or United States regulatory systems.

Under the present FAA part 137 the FU24-950 is eligible for operation in the United States in the restricted category at a maximum weight of 4600lbs.

By comparison CAA Part 137 states that an agricultural aircraft may be operated at a weight equal to the aircraft’s certified weight multiplied by the appropriate factor taken from the graph in Appendix B (31% for the FU24 or 6366 lbs). The pilot may operate at this new maximum weight subject to his assessment of the prevailing conditions, particularly strip length and wind speed. Although the aircraft is now operating at a weight 31% above the weight the design was certified for, no engineering assessments or modifications to the basic airframe are required by CAA Part 137 or the TCDS.

If certification of this aircraft in accordance with CAM 8 Appendix A was attempted,13 the new maximum weight selected from the curve should have been used to complete all of the other checks listed in CAM 8 Appendix A section1.22, including substantiation of the landing gear and flight characteristics

12 Noise level is measured at certain distance from commencement of the take off run. The easiest way to keep the aircraft below a certain noise level is to lighten it, so it takes off sooner and climbs quicker. The aircraft continues to make the same actual noise, but as perceived by an observer at a fixed spot on the ground it is higher and further way and thus quieter.

13 Arguably as a new purpose built type it should have been certified under CAM 8 App B.



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If the curve is correct in predicting the wing reserve strength, operation at the Part 137 overload weight should not cause wing failures, but without modification of the other supporting structures an increase in their failure rates can be expected. The occurrence history of the FU24 will be examined in Chapter 5 of this report, but as a summary the results are:

FU24 Aircraft,

Defects reported to CAA 1970 -2007

Wing Undercarriage

7 90

Figure 3.3

Considering the long service history of FU24 operations in New Zealand, there have been relatively few wing defects recorded despite the arduous flying conditions. In the same timeframe the number of undercarriage defects has been much higher. This is consistent with Part 137’s application of the CAM 8 wing load curve without requiring any further analysis of associated structure such as the undercarriage. Part 137 Appendix B has only been in effect since October 1994. Section 5 Part 2 examines the FU24 undercarriage failure rate in detail and indicates an increase in the rate after 1994.

Current status of CAM 8 In February 1965, the FAA issued AC 20-22 which stated that the information in CAM 1, 3, 4a, 4b, 5, 6, 7, 8, 9,10,13 and 14 could be used in conjunction with specific sections of the CARs to which type were applicable. In effect this adopted CAM 8 for continued use with the new United States Code of Federal Regulations

Approximately 10 years later, in March 1975, AC20-33A temporarily deleted the reference to CAM 8, but two months later it was re-instated by AC 20-33B for use with small restricted category agricultural aircraft certified under Part 21, 21.25. This policy continued until July 1981 when FAA order 8130.2 eliminated CAM 8 from being used for certifying new restricted category agricultural aircraft.

In 1992 two manufacturers of agricultural aircraft petitioned the FAA to develop a new set of certification requirements strictly for agricultural aircraft. After a series of meetings, AC 21.25-1 was produced to detail the certification requirements. The agreement reached was that the certification requirements for agricultural aircraft would be all the requirements for FAR 23 (the standard light aircraft standard) less those requirements found inappropriate. An Appendix to AC 21.25-1 listed those requirements that were likely to be considered inappropriate. The test above was taken from the FAA AC 21.25-1.

CAM 8 is no longer operative in the United States, although the current requirements for the certification of restricted category agricultural aircraft are a development of the intent of CAM 8 Appendix B.



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Summary of CAM 8 and Part 137 Part 137 exempts any aircraft engaged in agricultural operations from the normal take-off weight, strip length and obstacle-free climb-out requirements.

Part 137 Appendix B contains a graph that indicates the certified take-off weight may be increased by up to 31% for the FU24 aircraft. Pilots are required to consider ambient conditions and their effect on performance, but no actual figures are provided.

The graph in Part 137 Appendix B was taken from figure 7-1 of CAM 8 Appendix A.

CAM 8 was intended as a guide to the certification of aircraft in the restricted category. CAM 8 was produced to detail the United States administrators’ policies with respect to Regulation 8 that governed certification in the restricted category. It was intended for use by USCAA staff and the aircraft designers working to produce or modify aircraft for agricultural operations. Appendix A provides a guide to certifying aircraft modified from existing (standard or ex-military) category aircraft. Appendix B details the requirements for purpose built agricultural aircraft.

The suggested procedure for modifying an existing aircraft for agricultural operations is laid out in section 1.22 of CAM Appendix A. One of the initial steps in the process was to determine how much of a weight increase the original aircraft wings were capable of supporting. Figure 7-1 was a guide to selecting a new all up weight based on a trade-off between manoeuvring ability and weight carrying ability. This new weight was then to be used for the subsequent engineering and operational assessments, and finally listed on the restricted category Certificate of Airworthiness.

Part 137 Appendix B has copied Figure 7-1 from CAM 8 Appendix A without requiring the subsequent engineering assessment and or modifications outlined in CAM 8 Appendix A. This is inconsistent with the intent of CAM 8.

The use of figure 7-1 from CAM 8 as a guide to safe operations by Part 137, without requiring engineering changes is likely to lead to an accelerated failure rate of load bearing components other than the wing, including, but not restricted to, the undercarriage.

CAM 8 was not an operational rule and does not provide guidance on the day-to-day operation of the aircraft or conduct of agricultural operations.

CAM 8 has been discontinued in the United States since 1982 and is no longer used as a certification basis. The intent of CAM 8 has been captured by FAR 21.25, which is an aircraft certification rule.

There are significant differences in the operating limitations placed on the FU24-950 in New Zealand and the United States. This suggests that Part 137 is not well harmonised with its equivalent in the United States.

Neither the FU24 nor Cresco aircraft have been certified to CAM 8. United States agricultural aircraft produced since 1950 have been certified to CAM 8 or its successors at the restricted category weight listed in their type certificate data sheets.

Notwithstanding the application of CAM 8 to Part 137,operation in the restricted category at weights higher than the MCTOW is feasible where the weight increase is supported by:



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a) A complete engineering assessment of the loads on the airframe at the increased weight.

b) A flight operations assessment of the aircrafts performance and handling characteristics at the nominated increased weight.

c) Publication of the ‘Restricted Category –Agricultural’ weight in the aircraft flight manual (usually by supplement).

CAM 8 formerly provided guidance on conducting engineering and flight assessments at increased weights. Although it is now discontinued, the intent of CAM 8 has been incorporated into the current restricted category certification practices of the United States and other countries.

Prior to the introduction of Part 137, the New Zealand Civil Aviation Department permitted operations at an ‘Agricultural Category’ weight that was detailed in Leaflet C.10-7. This weight amounted to a 12% increase for the FU24 as a typical example. Operation at this weight required a 6% climb gradient and publication of take-off distance information in the flight manual.

Chapter 3 - Conclusions

Conclusion 3.1 The overload provision of Part 137 do not provide an adequate basis for operations at weights beyond MCTOW.

Conclusion 3.2 The overload provisions of Part 137 do not adequately specify how a restricted category (agricultural) weight for a given aircraft type can be safely established.

Conclusion 3.3 The best way to establish a technically and operationally safe restricted category weight for the purposes of agricultural would be the establishment of a working grop consisting of industry representatives and operations GA operations staff, supported by ACU engineering staff.

Conclusion 3.4 There is a need to fully review current FAA practice for agricultural operations and current FAA certification requirements for new agricultural aircraft when developing the acceptable means. However, United States’ requirements should not necessarily be adopted without modification as New Zealand agricultural operations have unique and well-recognised characteristics that should be taken into account.

Conclusion 3.5 CAD leaflet C.10-1 to C.10-4 could be considered as a basis for establishing an acceptable means of operation beyond MCTOW.



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Chapter 4 CAA Safety Data Review Scope item 3: “Review NZ airworthiness schedules for all agricultural aircraft types currently in operation or under certification.”

Introduction This was the most time-consuming and in the end the most important part of the Review. The review of the occurrences had two significant findings:

a) The recorded occurrences show significant changes in the accident and incident rates, after changes in regulatory policies.

b) The CAA management of recorded occurrence information could be significantly improved to provide more useful safety management information.

Because of the significance of the findings, it is necessary to understand how the information presented in this chapter was derived. For example it is not currently possible to interrogate the CAA database for a listing of ‘Agricultural Aircraft Occurrences’. A method of doing this had to be developed during the course of the Review. The method has application for future use by the CAA, as well as implications for the way safety occurrence data is handled, so it is detailed in Section 1 of this Chapter.

Section 2 of this chapter discusses the results of the analysis of the data collected.

Section 3 provides some supplementary information related to aircraft characteristics. This information assists in the interpretation of the data in Section 2.

Section 1 - Collection Method This chapter details the data collection and analysis methods. Readers may wish to proceed to Section 2 which discusses the results and return to this section.

The first problem in accomplishing the review of agricultural aircraft occurrences is that it is not possible for the CAA database to provide a list of ‘Agricultural Aircraft Occurrences’ The database can list occurrences by aircraft model, or by occurrences type and various combinations, but ‘Agricultural Aircraft’ is not a defined category for occurrences, although it is used by the Safety Analysis Unit SAU) as an industry sector category. It may be possible in future to categorise occurrences by industry sector or operational type, which would make the process employed by the Review much easier to perform.

Occurrence Types The CAA database categorises safety occurrences into 14 types. Accident is an obvious occurrence type, and the category ‘defects’ includes serious faults whether found in service or scheduled maintenance. The third type of occurrence considered by this review was the category ‘incidents’. An incident is as serious event that is not an accident. An example could be the loss of engine power in flight, followed by a successful emergency landing. Aviation Related Concerns (ARCs) were also considered as this is sometimes used a catch-



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all category, but there were not significant numbers of ARCs involving agricultural aircraft, apart from low flying complaints.

Identification of ‘Agricultural Aircraft Types’ All aircraft operators in New Zealand are required by Part 12 to report events that have safety implications. The CAA stores the occurrences in a database.14 The occurrences are categorised into 14 types and the database can be interrogated to provide a list of all occurrences of a certain type or all occurrence types for any one aircraft model.

To review all the occurrences involving agricultural aircraft, the first step was to determine which aircraft models can be classified as ‘agricultural aircraft’. While some of these aircraft models were reasonably obvious such as the Pacific Aerospace (PAC) Cresco and FU24 aircraft series, numerous other types have been involved in agricultural work over the years. Since 1994 agricultural operators have been required to submit returns to the CAA detailing the hours flown on agricultural operations, along with the aircraft type. This data proved useful in determining which aircraft types had been deployed on agricultural operations. It also provided some information about the relative exposure of certain aircraft types to agricultural operations, and the way in which this changed with time. This information was produced by the SAU and after manipulation in MS Excel, produced the following graphs (Figures 1,2 and3).

Figure 4.1

14 MS Access based



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Figure 4.1 shows the total hours reported on agricultural operations per year from 1994-2006, divided into fixed wing and rotary wing. It is notable that the total hours flown by fixed wing aircraft has remained almost constant while rotary wing aircraft have steadily increased their hours. It is also apparent the helicopter hours are being flown in addition to the fixed wing hours. Helicopters are probably moving into new areas of operation and not taking over the bulk spreading of solid fertiliser that is still the domain of fixed wing operations. There appears to be a long-term almost sinusoidal variation in both fixed wing and rotary agricultural operations. This cycle, which seems to be almost 10 years long, is probably linked to agricultural commodity prices, exchange rate, weather conditions or a combination.

Figure 4.2

Figure 4.2 takes the rotary wing hours portion of Figure 4.1 and breaks it down by helicopter type. This graph shows how some types such as the Bell 206 Jet Ranger, (mid blue) and the MD 369 ‘Hughes 500’(dark red) have performed an almost constant amount of work over the years while newer types such as the R22 (olive green) and its bigger brother the R44 (orange) have increased their operations in recent years. As the agricultural rotary wing accident rate was so much smaller than the agricultural fixed wing accident rate, the review has not examined rotary wing agricultural operations any further.



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Figure 4.3

Figure 4.3 takes fixed wing agricultural aircraft and breaks down the annual reported hours by type. A number of observations can be made from this graph.

a. The two most numerous Pacific Aerospace aircraft types, the FU24 series and the 08-600 Cresco, have shouldered the burden of agricultural operations. In 2007 between them they contributed about 80% of the agricultural operating hours.

b. The FU24 has slowly surrendered some of this workload to the 08-600 Cresco since its introduction in the early 1990s.

c. Other significant agricultural types such as the Cessna Agwagon and AirTractor series have flown fewer hours in recent years,.

Because the FU24 and Cresco comprise the bulk of agricultural hours, statistically it could be expected that 80% of the agricultural aircraft safety occurrences will involve either the FU24 or Cresco models. The following section examines the safety occurrence history of the FU24 and Cresco in more detail than some of the other types because they comprise such a significant proportion of the hours flown. The next most ‘exposed’ types are the GA200, AirTractor series, Ag wagon and Zlin.

Unfortunately for this analysis the CAA database counts the FU24 series as 15 different models, listed below, so the database had to be interrogated carefully and repeatedly to ensure all of the FU24 series occurrences where captured. The Cresco and 750XL and the various Air Tractor models were much more straightforward, only two Cresco models appear in database. It was realised that there is a function in the CAA Explorer under



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‘Reporting’ ‘Operations’ then ‘Analysis and Tools’. This function requires a search by aircraft, one model per search, along with other event descriptors’ such as ATA fault code, so each model had to be searched several times. This became very cumbersome for the FU24 series, and did not pick up several occurrences that were already known to the author, because of the way the data for a given occurrence had been entered. For these reasons an alternative approach was developed as follows.

Popular_Name Aircraft_Model Model_Id Manufacturer_Name

Fletcher FU24 454 Air Parts (NZ) Limited Fletcher FU24-950 456 Air Parts (NZ) Limited Fletcher FU24-950 457 New Zealand Aerospace Industries Limited Fletcher FU24-950M 458 Air Parts (NZ) Limited Fletcher FU24-950M 459 New Zealand Aerospace Industries Limited Fletcher FU24-950M 460 Pacific Aerospace Corporation Limited Fletcher FU24-954 461 New Zealand Aerospace Industries Limited Fletcher FU24-954 462 Pacific Aerospace Corporation Limited Fletcher FU24A-950 463 New Zealand Aerospace Industries Limited Fletcher FU24A-950M 464 New Zealand Aerospace Industries Limited Fletcher FU24A-954 466 New Zealand Aerospace Industries Limited Fletcher FU24-950M 1091 Fletcher Aviation Corporation Fletcher FU24-950M 1092 Sargent Fletcher Company Fletcher FU24A-950M 1097 Fletcher Aviation Corporation Fletcher FU24A-950M 1098 Sargent Fletcher Company

Figure 4.4 FU24 Model ID Table

Figure 4.4 lists the 15 different Model ID numbers that have been assigned to the FU24 series. This was done intentionally as the aircraft differ in detail and ownership of the design has passed between different corporate identities. Note also that there is no unique model ID for FU24 that have been converted to turbine power, they are considered to be the same as the donor aircraft for reporting purposes. This makes it impossible to directly extract safety information for turbine powered FU 24 aircraft.

Nonetheless due to the interest in piston vs. turbine FU24 accident rates, the SAU compiled a breakdown of the number of hours flown by piston and turbine variants and this information is shown in figure 4.5. This graph shows how turbine variants have increased their share of the total FU24 hours as the aircraft were converted in increasing numbers from 1998-2004. Since then approximately 50% of the hours reported for FU24 aircraft have been flown by turbine variants (primarily Walter M601D-11NZ under Supplemental Type Certificate (STC) 21E/98/15). Note also the total hours flown by the FU24 fleet has steadily declined. This is due to the fact the aircraft are no longer in production and there has been some attrition in the number of active aircraft. The attrition is due to both accidents and intentional retirement.



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Figure 4.5

Identification of the Significant Agricultural Types From the reported hours statistics it was apparent that although there were more than 20 types conducting agricultural operation in the period 1994-2007, the analysis could be more usefully concentrated on those few significant types that contributed the majority of the operating hours.

By combining the reported agricultural hours statistics with the recorded occurrences for each type the following table was produced. As expected the highest number of occurrences are recorded against the aircraft types that flew the most hours. This table also establishes that almost 99.9% of agricultural operations were conducted by nine aircraft types. This was a much more manageable number for review and comparison. Note the occurrence statistics go back to 1970 but the hours only to 1994, so this table cannot be used to determine occurrence rates per flying hour. This is also why the Airtruk has recorded a significant number of occurrences while not reporting many hours, these occurrences occurred prior to 1994, by which time the aircraft type had almost been retired. Accordingly, the Airtruk occurrences were not analysed any further. For reference Figure 4.8 contains an illustration of the Transavia Pl-12Airtruk and the recorded occurrences are listed in Annex K



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Type Hours 1994-2007

% of Total Hours

Occurrences 1970-2007

FU24 384478 65.08 609 Cresco 130111 22.02 341 750XL 3001 0.51 31 GA200 31590 5.35 32 AirTractor 16237 2.75 9 Agwagon 15081 2.55 106 Zlin 5174 0.88 45 AgCat 4255 0.72 8 Airtruk 405 0.07 15 Sub Total 589928 99.85 1196

All Ag Hours 590971

Foreign Ag Hours 62908 10.65 Figure 4.6

Graphically the relative percentages of the almost 0.6 million hours flown on agricultural operations between 1994 and 2007, are shown below in figure 4.7.

Figure 4.7

For aircraft types other than Pacific Aerospace types, the fleet size of each model was so small that meaningful analysis of the occurrence statistics is difficult. Accordingly to



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provide some meaningful comparison, the three most popular non-PAC types were grouped together as ‘Foreign Ag Types’ which together made up just over 10% of the hours. This allowed some reasonable comparisons to be made between the FU24 (65%) Cresco (22%) and the foreign agricultural types (10.65%) which consisted of the Air Tractor variants, The Cessna Ag Wagon variants and the Gippsland GA200 Fatman variants.

Identification of Occurrences for Significant Agricultural Types By the process described above, the various aircraft types, which could be considered significant agricultural aircraft were determined. This made it possible to interrogate the database to find all the occurrences recorded for these types. This produced a list of 1196 separate occurrence files to analyse.

The significant agricultural aircraft types are illustrated on the following pages for reference.



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Significant Agricultural Aircraft Types in New Zealand

Figure 4.8 Pacific Aerospace FU24-950 ‘Fletcher’

Figure 4.9 Pacific Aerospace 08-600 ‘Cresco’



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Figure 4.10 Turbine Conversions Ltd FU24’Walter Fletcher’

Figure 4.11 Pacific Aerospace Ltd 750XL



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Figure 4.12 Zlin Z-137T

Figure 4.13 Transavia PL-12 Airtruk



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Figure 4.14 Cessna A188 Agwagon

Figure 4.15 Air Tractor AT-402B



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Figure 4.16 Gippsland Aeronautics GA 200

Figure 4.17 Douglas DC-3 For reference, no longer used

.



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Occurrence Categorisation By the process described all the CAA recorded occurrences, i.e., accident, incidents, and defects for the principal agricultural aircraft types were identified. This comprised 1196 occurrences listed in date order from 1970 to mid 2007. To analyse this data a means of sorting it had to be devised.

While the review was being carried out the CAA also carried out an accident investigation on ZK-DZG, an FU24 aircraft that crashed in November 2006 killing both crew members. The accident investigation revealed that the fin had failed in flight, which generated interest in how many other fin failures, near failures or even slight defects had been recorded. Unfortunately the CAA database could not be searched reliably for occurrences attributed to defects of a certain component. While it was possible to search for occurrences involving a certain part number, this field was far from consistently filled in, particularly for occurrences prior to 1994. Searches by this method failed to find even those occurrences that the author was already aware of. Sometimes the ‘defective part’ field was blank, other times the same component had been given various descriptions, i.e. Fin, Vertical Stabiliser, Rudder, Tail, 240253-1. To get any sort of useful meaning from this data a system of classification was required.

The occurrence data for each model was classified by running a report in the database for each model using the same set of fields. The primary fields were ‘Occurrence Number’, ‘Date of Occurrence’, ‘Aircraft Registration’ and the ‘Description’. The database report could be exported to a MS Excel spreadsheet to allow further manipulation. Once it was in the spreadsheet each occurrence was assigned a classification code from the following table. The classification codes were typed into the spreadsheet manually after reading the description of each event. Where the description itself was not clear enough, the occurrence itself could be opened back in database to get more details. This was time consuming process. The description was used to determine the classification according to the following table. The occurrence codes are arbitrary, fin related problems were a priority at the time so given the code ‘1’, the next biggest concern was undercarriage, hence they were assigned a ‘2’ and on down assigning a new code to each classification as they were encountered.



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Code Category

0 Unknown1 Vertical Stabiliser (fin and rudder) 2 Landing Gear 3 Wing Attachments 4 Engine Mount 5 Turbine Engine 6 Piston Engine 7 Operational Error 8 Propeller 9 Performance 10 Electrical 11 Controls 12 Fuel 13 Horizontal Stabiliser 14 Wing 15 Fuselage 16 Pilot Medical

Figure 4.18

Consideration of ATA Code Use For the defects, the ATA code system could have been utilised. ATA codes were developed by the Airline Transport Association and are used to classify aircraft systems into categories to introduce some common formats into documents such as maintenance programs. The use of ATA codes is current practice by the Safety Investigation Unit when entering defects into the database. Some ATA codes are quite broad unless the sub codes are used, for example ATA code 27 Stabilisers would cover both the vertical fin and the horizontal stabilisers. In addition ATA codes are not applicable to the accident and incident occurrence types, such as operational error, performance, pilot medical.

While the classification system developed for this project was essential to enable the following data analysis it was very time consuming to implement. In addition a reasonable amount of experience and judgement is required. As this process has produced some very useful information, that have potential uses for other operational areas, it is recommended that the CAA Safety Information Group consider how aspects of this method of data analysis could be incorporated into the CAA information management system.

Conclusion 4.1 The current CAA safety information management system does not permit easy analysis of certain safety data. The techniques used in the Review could be adapted to provide the CAA with enhanced research capabilities.



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Operational Error and Performance Classifications Most of the classification codes are self evident except the following two that require explanation. At first glance there were a lot of occurrences that were clearly, ‘no fault of the aircraft’ Typically these were accidents where a serviceable aircraft had collided with an object. These were originally given the code 7 “Operational”. As the classification process wore on it became apparent there were two subtypes of operation error. While some of the accidents occurred on landing, or in ground manoeuvring, there were a number that had fairly consistent description such as “aircraft encountered sink on takeoff”, “sudden tail wind prevented aircraft from getting airborne”, “aircraft commenced dumping but hit fence at end of strip”. The common feature of these accidents was that they occurred during or shortly after takeoff and involved combinations of high aircraft weight, and/or reduced aircraft performance. In short these were occurrences where the aircraft lost its ongoing battle to overcome gravity. These were quite different from the landing or ground handling accidents where the aircraft had performance to spare but was mishandled. While it would be unfair to say that all of the ‘failure to remain airborne’ accidents imply the aircraft were overloaded, all of the operational occurrences due to overloading will be found in this group.



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Section 2 - Analysis by Type

Introduction Part 1 of this chapter detailed the methods used to extract from the database all the CAA recorded safety occurrences for the significant agricultural aircraft types operated in New Zealand since 1970. The final result was 609 occurrences for the FU24 series, 341 for the Cresco and 147 for the three principal foreign types combined.

For aircraft types other than the FU24 and Cresco, the number of occurrences was too small to provide meaningful data on trends and rates. Hence some of the following analysis concentrates on the FU24. This is primarily because it was the largest single set of data, but also because the predominance of the FU24 as a type meant its occurrence statistics it could be used as a reasonable approximation to the whole of the industry. The concentration on FU24 statistics is not intended to suggest the type has particularly poor safety record except where a direct comparison is made between it and other types.

Reporting Rates. There have been suggestions that industry is not reporting occurrences to the CAA as frequently as it used to. The investigation of unreported defects was scope item number 4 and is covered in Chapter 5. This review determined that reporting of defects to CAA, while certainly less than 100% of actual events provides a reasonable picture of events, and has not markedly reduced in recent years.



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Occurrence Category Breakdown - PAC Aircraft The following graphs show how the occurrences vary by category for the three Pacific aerospace types, the FU24, the Cresco and 750XL.

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Figure 4.19

FU24 Series reported 609 occurrences from 1970 to 2007. Leading cause was operational error, followed by piston engine defects (this is all occurrences, not necessarily failures).

Almost equal with piston engine defects are the number of landing gear defects (90). Vertical stabiliser defects are noticeably more evident than wing, or horizontal stabiliser defects. Performance occurrences are also common for this aircraft type. The FU24 data is analysed in more detail in the following pages.



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Figure 4.20

For the Cresco, operational error occurrences decrease markedly, as do performance occurrences. When this graph was discussed with industry many agreed this was probably due to the fact that pilots graduated to the Cresco from the FU24 so were typically more experienced, hence a reduction in the ‘operational error’ category. The superior performance of the 750 HP Pratt & Whitney PT6-34AG engine in the Cresco appears to have to reduced the number of ‘performance’ occurrences. The Cresco has a good power to weight ratio which tends to decrease the occurrences of ‘performance’ incidents. For a comparison of aircraft power/weight ratios, refer to Section 3 of Chapter 4.

The more disturbing statistic from the Cresco graph was the high number of control system and landing gear defects. Considering the control systems category first, this category includes ailerons, elevators rudders, flaps and trim controls. Within this category many of the defects were with the trim system. The predominance of control system defects was a surprise to the CAA Aircraft Certification Unit and the manufacturer. Until this review defects had been investigated by the CAA on a case-by-case basis without grouping related failures. While the CAA and industry were becoming aware of a relatively high number of landing gear failures, the less dramatic control defects had gone unnoticed. It is worth considering that landing gear failures, while they can lead to a loss of control during a critical phase of flight (take-off or landing) can only occur on or very close to the ground, while control system failures can occur at any time in flight.



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The 750XL shares many of the same parts from the Cresco, and although the total number of occurrences was very low, the data suggests already that some problems may have been carried over. For example its leading defect category is the control system.

Figure 4.21

In the preceding graphs note the vertical scale changes to reflect the lower overall number of occurrences for the Cresco and 750XL models, due mainly to their shorter time in service.

Figure 4.22



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The graph above shows the PAC aircraft faults category to the same scale. The different lengths of service for each type have an obvious effect on the absolute numbers of each occurrence category, but there are some common feature to the shape of the distributions. For example both the FU24 and Cresco have significant numbers of defects in the landing gear, engine mount and vertical stabiliser categories. The Cresco differs from the FU24 in the Operational Error, Controls and the Wing, Fuselage and Horizontal Stabiliser categories.

The Cherokee as a Control Case The occurrence data for the three PAC products was shared with the manufacturer on 19 November 2007. Up until that time CAA contact with PAC had been on a occurrence by occurrence basis, so this sort of trend information had not been previously presented. In particular the relative number of control system problems caused concern, During that meeting PAC raised the valid point that the high incidence of control problems could be just a natural attribute of the way the data was collected, i.e. a very broad category that inherently collects many occurrences.

Figure 4.23

In response, the same data collation exercise was performed for the Piper PA-28 Cherokee series. The Cherokee was chosen as the ‘control’ as it is an all-metal low-wing piston monoplane of similar configuration and vintage to the FU24. In addition, the FU24 designer, John Thorpe went on to design the Cherokee, and some aspects of their construction are similar, such as the simple oleo landing gear. The resulting distribution of defect occurrences is shown below.



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Figure 4.24

It can be seen that the distribution of defects is quite different between these otherwise similar aircraft types. The distribution of defects thus represents the true behaviour of a given aircraft design in service. From this graph the FU24 controls are more than twice as likely to give problems as the same items on the PA28, and the Cresco was even more likely than the FU24 to have control problems. It will be noted that the number of occurrences is comparable and the date range is the same and that both aircraft types were in service throughout 1970-2007. The high number of PA-28 electrical occurrences deserves explanation. A large number of these were radio problems. The PAC aircraft had reported only a few radio problems so ‘Radio’ was not chosen as a separate category, they were combined with the relatively few other electrical system faults. When it came to categorise the PA28 occurrences, for consistency the radio faults had to be included with ‘electrical’. This is an example of how the analysis method developed for this review would need to be modified if it were to be used more widely by the CAA.

Conclusion 4.2 This comparison verifies the validity of the occurrence categorisation method as a way of comparing the relative service history of different aircraft designs. The distribution of occurrences is a function of both the soundness of the design and its operating environment. Together they represent the design’s fitness for purpose or airworthiness.



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FU24 Detailed Occurrence Analysis.

With the occurrences sorted by aircraft type and occurrence category, it was possible to further analyse categories of interest. The principal concerns expressed by industry for the PAC FU24 aircraft included, 15

• Fin structural defects

• Undercarriage defects

• Engine mount defects,

In addition the CAA was concerned about possible overload related occurrences, particularly due to the conclusion reached by the Lewis Report.

Scope item 2 of this report set out to review the CAA recorded occurrences to see if there was any basis for these stated concerns. To examine the validity of industry claims that defect rates were rising the various defect types were plotted against their date of occurrence to detect any significant change in the rate of occurrences over the available history.

The following graphs show the cumulative number of occurrences plotted against date of occurrence. Thus the local slope of each curve gives the rate at which that defect is occurring, (i.e. defects per year). This data is not normalised for flying hours because of difficulties with the way the data was presented by the database and the fact that the occurrences go back to 1970 but agricultural hours have only been reported since 1994. However if the FU24 fleet hours of Figure 4.5 are kept in mind, which showed a steady reduction in FU24 flying hours since 1994, the effect of normalising would be to steepen all the FU24 curves in recent years.

15 Industry Concerns are detailed further in Chapter 9.



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Figure 4.25

Fin Defects. Points with aircraft registration marks denote in-flight fin failures. In all cases severe directional control difficulties were experienced, but in 6 cases emergency landings were achieved. The pilot of ZK-BPY lost control during the landing and was seriously injured. The pilots of EGO and DZG were both killed after losing control of their aircraft.

The blue crosses denote when a fin structural defect was reported. The in-flight failures prior to ZK-EGO were due to failures of the fin attachment fitting. No fitting failures or defects have been reported since they were replaced by steel items per Airworthiness Directive DCA/FU24/172. Both ZK-EGO, and ZK-DZG were failures of the skin outboard of (above) the fitting. Note increase in rate of reported defects since ZK-EGOs accident in 2001. While it is possible that this is true increase in defects due to aging aircraft it is more likely that industry have been more inclined to report defects since the fatal failures of ZK-EGO and ZK-DZG, or that the AD has raised awareness of the critical nature of these defects, or both of these reasons. Vertical lines indicate when the three ADs concerning FU24 fin airworthiness were released.

A detailed summary of each of the fin failures on the FU24 and Cresco aircraft is included as Annex M.



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0

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1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

FU24 Engine Mount Defects

Engine Type Lycoming IO-720

Walter M601D-11NZ

Pratt & Whitney PT6

Figure 4.26

Engine Mount Defects Figure 4.26 displays the occurrence of engine mount defects for the FU24 series, including the engine type. There were only two engine mount defects recorded prior to 2000. The category ‘Engine Mount Occurrences’ includes bolt fractures, and fractures of the engine mount structural elements. All but one of the failures since 2001 were of turbine converted aircraft for which the engine mount is a new part number, installed under a Supplemental Type Certificate, or modification approval.

Individual occurrences are colour coded to denote the aircraft engine type. Walter engine conversions and Pratt & Whitney PT6 conversions have dominated the recent increase in engine defects, although failures of the original engine mounts are not unknown.

Considering the failure rate of the turbine converted aircraft engine mounts, it is unlikely that the engine mount designer miscalculated the loads. Other explanations include the possibility that the certification load case does not adequately describe the loads seen in service, or that the installation was not carried out correctly. Some of these failures include fatigue fractures of the attachment bolts which was due to the intended installation procedure being unable to be followed. As a result an alternative was developed which resulted in the bolts being inadvertently installed with insufficient torque. This left them vulnerable to cyclic loading and resulted in fatigue failures. This problem has been addressed, in which case a levelling off in this curve can be expected. Note that this analysis has intentionally grouped failures of the engine mount tubes, gussets and bolts as they all represent a failure of the engine mount assembly to perform its intended function. As such they need to be considered together in assessing the overall airworthiness of the engine mount assembly. Appendix N discusses the method of grouping the failures of related systems with particular reference to the FU24 vertical stabiliser.



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Figure 4.27

FU24 Performance Occurrences Figure 4.27 shows the cumulative total of the FU24 performance related occurrences plotted against the date of occurrence. The slope thus indicates the rate of occurrences with respect to calendar time. There is some ‘noise’ in this curve (variability). This is due to the fact that there are a number of contributing factors for performance occurrences and they include environmental effects such as gusting tail winds and natural downdrafts.

Nonetheless there are four distinct slopes to the curve. The three most significant are marked with dotted lines. The purple line indicates an almost constant rate from 1979 until 1994. In this period the FU24 fleet was largely composed of 400HP FU24-950 or the modified 950-M variants. Around 1994 the rate trends upwards, after the overload provision of Part 137 Appendix B increased the take-off weight from 5430lbs to 6366lbs. After 2001 the rate decreases sharply. This is likely due to the increasing numbers of turbine Fletchers entering service. With 550HP available for take-off and initial climb the aircraft have better performance making them are less likely to hit the fence at the end of the strip on takeoff. Note the rate of occurrences (slope) post 2001 falls back to a similar rate to the 400HP aircraft in the period 1978 to 1994. In the aircraft comparisons table of Chapter 4 Section 3, the power to weight ratio of the 400HP FU24 was 0.074 HP/lb at the pre 1994 Ag category weight (12% overload). It dropped to 0.063 at the part 137 overload (31%) weight and then rose to 0.086 under the Part 137 weight (31%) with Walter turbine engine. This confirms what most pilots would intuitive understand; the rate of performance related accidents is inversely proportional to the aircrafts power to weight ratio. The higher the power to weight the fewer performance related accidents.



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FU24 Landing Gear Occurrences From the overall reported hours and overall number of occurrences the following was comparison was made between the FU24 and the foreign agricultural types as defined in Chapter 3 Section 1.

Period 1994-2007

Reported Agricultural Hours 590790 (0.6 Million)

FU24 undercarriage defect rate

0.151/1000 flying hours

Foreign Ag types undercarriage defect rate

0.111/1000 flying hours

FU24 undercarriage defect rate is 36% higher than Foreign Ag Types Figure 4.28

While the FU24 could be expected to have a higher rate of undercarriage failures than the light private use PA28, it should have been comparable to other agricultural types. For more detail the occurrences were plotted against time, as shown below.

Figure 4.29

Undercarriage Occurrences Figure 4.29 is a very interesting graph. The large number of defects (90) and long operating history of the FU24 makes it a particularly useful illustration. The striking feature of this graph is that it has two distinct sections of almost constant slope, with a



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transition in between. From 1977 to 1994 the rate of landing gear defects per year is a fairly constant rate. After 1994 there is a sudden increase in the rate, and from about 2000 the rate becomes almost twice as great as it was before 1994. Possible reasons for these changes include:

In October 1994 Part 137 Appendix B was introduced which permitting a take-off weight up to 31% greater than the maximum certified takeoff weight.

From 2000, appreciable numbers of FU24 aircraft were converted to Walter Turbine power (STC). Take-off (five minute) power rating was 550HP rather than the 400 HP of the FU24-950 series. The engine power does not directly affect the load on the landing gear. However if the aircraft was previously limited in the load it could accelerate to flying speed within the available strip length, then an increase in power would allow it to accelerate a greater load up to flying speed. During the takeoff roll with the heavier load, the landing gear will be subjected to increased stress from:

• Increased weight on board,

• The higher take-off speed,

• Longer ground roll.

There is another distinct step in both the undercarriage and performance occurrence curves around 1978. Possible reasons for this step include the fact in 1978 the FU24-950 was modified to replace the 37 cu ft hopper with a 46 cu ft Hopper. (NZ Aerospace Industries (the manufacturer) modification AI/FU/0051 and flight manual supplement 19 dated 23 July 1978, refers.) The larger hopper was intended to accommodate poisoned carrots for rabbit control. Carrots have a relatively low density compared to superphosphate, and no increase in overall weight was approved. The commensurate increase in landing gear defect rates indicates that some operators at least attempted to exploit the larger hopper to carry increased loads of superphosphate. A further comparison of the various hoppers fitted to the FU24 series is contained in Chapter 10.

The 400HP FU4-950/950M was introduced in 1970. Its MCTOW was increased to 4860lbs. Aircraft operating prior to 1970 were 250-300 HP six cylinder variants of the FU24, with a MAUW ranging between 3550 lbs (225HP) to 4000lbs (310HP).

Certification of Landing Gear Loads The condition of the certification of aircraft in accordance with FAR 23.473 generally applies a limit load that is a function of the aircraft’s landing weight and an assumed high rate of descent (600fpm or about the usual rate of descent for landing). This load case usually provides a load higher than all other loads likely to be encountered in normal operation. Designing to meet this criteria produces a durable landing gear design. An ‘over-loaded’ agricultural aircraft carries a much higher load at take-off than it does at landing. The takeoff speed of an ‘over-loaded’ agricultural aircraft is increased above the landing speed. Combined with the rougher strips of agricultural operations, these factors may combine to produce operational loads on the landing gear that are not covered by the FAR 23.473 case of a landing at MCTOW at high rate of descent.



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Hence operation of an aircraft using the overload provisions of Part 137 App B will increase the likelihood of generating loads on the landing gear that are close to or in excess of the design case. This is likely the cause of the increase in rate of failures after 1994.16 .

In practice the overload provisions of Part 137 Appendix B are limited by the ability of the aircraft to reach flying speed within the strip length available. Acceleration rate is a function of engine power, or strictly thrust. Hence an increase in engine power increases the load that can be carried out of a given airstrip. The heavier ‘average’ aircraft load will increase the forces experienced by the landing gear. Comparing Figure 3 which shows significant numbers of turbine converted aircraft entering service in 2000-2001, with Fig x suggests a strong correlation between the advent of the turbine Fletcher and an increase in undercarriage defects. Figure 4.30 is an enlargement of the figure 4.29 showing the engine types of the FU24 variants that reported landing gear defects since 1990.

Figure 4.30

16 Chapter 3 details the background to Part 137 and its introduction of a 31% overload in place of the previous 12% increase permitted by CASO 4 prior to 1994.



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Cresco Detailed Analysis There are only two recorded occurrences where performance/weight was an issue for the Cresco, hence no trend analysis is possible (one was fatal, ZK-TMO near Gisborne 2001)

Undercarriage failures for the Cresco are common, 67 occurrences since 1983 and 66 since 1993 The Cresco’s did not enter service in significant numbers until the PT6 powered variant was developed in the early 1990s. Cresco in service before 1994 were powered by the Lycoming LTP1-101 of 600HP. The release of the 750HP PT6 variant almost coincides with the introduction of Part 137, so the marked change exhibited by the FU24 is not so apparent. Still over the service life of the Cresco, the undercarriage defects rate can be summarised as follows:

Pacific Aerospace 08-600 Cresco Undercarriage Defect Rate

67 defects 130111 Ag flying hours 0.515 failures/ 1000 flying hours 7 defects 62908 Ag Flying Hours 0.113 defects/ 1000 flying hours

The Cresco undercarriage defect rate is approx 450% of the rate for the foreign agricultural aircraft

Figure 4.31

In considering the Cresco undercarriage defect rate the following should be noted. The undercarriage of the Pacific Aerospace Cresco was certified to FAR 23.732 at the standard category weight of 6450lbs17. Part 137 Appendix B permits it to be operated at 8256lbs. The undercarriage defect rate of the Pacific Aerospace Cresco is 4.5 times that of the foreign designed agricultural aircraft.

Figure 4.32 ZK-TML Cresco. Landing gear failure on takeoff 13 Nov 2006. CAA Occurrence 02/3231

17 New Zealand Aerospace Industries Report 08-40



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Foreign Agricultural Types Detailed Analysis

Air Tractor With only 9 occurrences of all categories, no trend analysis of Air Tractor occurrences is possible, however they have been included in the ‘Foreign Agricultural Types’.

Gippsland GA200 The GA200 suffered seven performance occurrences in seven years between 1998 and 2005 a reasonably constant rate. There were only two recorded GA200 undercarriage failures.

Note that significant overloading of the GA200 beyond Part 137 is not possible due to the physical size of the hopper (800 litres) which equates to 2115 lbs of superphosphate which generally keeps it within the agricultural operations weight listed on its type certificate data sheet.

Cessna Agwagon Like the AirTractor and the GA200, the Cessna Agwagon uses solid spring steel landing gear legs as opposed to the oleo pneumatic legs of the FU24 and Cresco. The Cessna spring leg design was reportedly less robust and during the mid 70’s when these aircraft were popular a number of failures were recorded. The failure rate appears to reduced with time most probably due to the fall off in number of Agwagons operating (recalling that this data is presented per calendar time not flying hour).

Due to the small fleet numbers and fluctuations of the fleet size with time, analysis of each of the foreign aircraft occurrences was less useful; than it was for the FU24. Accordingly the three popular foreign types were combined to even out the fluctuations. Collectively the foreign agricultural aircraft equivalents to the FU24 data is shown in the following two graphs figure 4.33 and figure 4.34

From these two graphs it can be seen that there is no marked variation in landing gear failure rates of the foreign aircraft types in either 1994 or 2001, and there is only a slight step in performance occurrences post 1994, and none post 2001. This indicates that the steps in the FU24 occurrence rates are specific to the aircraft and not artefacts of the collection method, or an industry wide effect, such as climate change effecting strip surfaces.

It is also worth noting the Agwagon had largely ceased operations by 2000, and both the GA200 and AirTractor hopper capacities limit their ability to exploit the overload provisions of 137 App B. See Chapter 11 for a discussion of hopper capacities



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Figure 4.33

Figure 4.34



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Data Analysis Conclusions:

Conclusion 4.3 The FU24 has suffered a high rate of landing gear failures, compared to the three most popular foreign agricultural aircraft types. The FU24 failure rate between 1994 and 2007 is 136% of the foreign agricultural aircraft landing gear defect rate.

Conclusion 4.4 The rate of FU24 landing gear failures has increased markedly since 1994 when Part 137 introduced the permissible overload graph in appendix B.

Conclusion 4.5 The rate of FU24 landing gear failures increased even more dramatically in 2001 when approx 50% of the fleet were converted to turbine engines. This is most likely because the 38% increase in takeoff power allowed the overload provisions to be more fully and more frequently exploited. This lead to higher average loads on the landing gear and more frequent exposure to very high loads.

Conclusion 4.6 The Cresco suffers a high rate of landing gear failures. The PT6-34 powered Crescos entered service after 1994, so there is not sufficient data to gauge the rate of failure before Part 137 App B. They have served their whole life under the provisions of Part 137 Appendix B . Since entering service it has suffered 0.515 failures per 1000 flying hours. This rate is 3.4 times higher than the FU24 rate and 4.5 times higher than the foreign agricultural aircraft landing gear defect rate.

Conclusion 4.7 The three foreign agricultural aircraft types when analysed the same way do not show significant increases in undercarriage failures in either 1994 or 2001, ruling out external factors as a cause of the increase.

There is a small increase in the performance related accidents post 1994, which may have been due to operators exploiting or even exceeding the provisions of part 137 although the hopper capacities of the foreign agricultural aircraft has limited the degree of overload to approx 10% with superphosphate.



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Chapter 4 - CAA Safety Data Review

Section 3 - Aircraft Comparisons. During the course of this research it was necessary to consider the various aircraft types and their principal parameters. The following table was compiled from CAA and industry sources to provide a ready comparison of various aircraft parameters.

This table lists the aircrafts’ vital statistics such as empty weight, maximum certified takeoff weight, engine power ratings, wing area and hopper capacities. These are all parameters relevant to agricultural operations. Other aircraft characteristics such as length height and wing span which were not relevant to their operations at high gross weights have not been included. These figures have been compiled from CAA records and industry sources an while all due care has been taken they should be taken as indicative figures only.

In this table the FU24 and Cresco variants have an ‘agricultural category weight’. This was a weight applicable to restricted category operations that was published in the flight manual in addition to the maximum certified takeoff weight (MCTOW) for standard category operations. Chapter 3 details how this was derived by the then Civil Aviation Department, and how it was accompanied by a reduction in the permissible load factor, from 3.8 to 3 G. For the FU24 the agricultural category weight was 12% higher than the MCTOW. The PAC 750 XL was produced after 1994 and never had an ‘Agricultural Category’ weight, hence it is shown as the same as MCTOW. For the Air Tractor, Ag wagon and GA200 aircraft (the foreign agricultural types) the agricultural category weight is taken as the ‘Restricted Category’ weight as listed in the flight manual or type certificate data sheet.

Power to Weight Ratio An interesting comparison that can be drawn from this table is the relative power to weight ratio. Generally the aircrafts performance and manoeuvrability increase with power to weight ratio. For example fighter aircraft tend to have a high power to weight ratio and transport aircraft have a lower ratio, which is reflected in their manoeuvrability. Annex O provides further details on the influence of power to weight ratio on manoeuvrability in the horizontal and vertical planes. The power to weight ratios of significant agricultural types is shown graphically in figure 16 .

Type Empty Weight (lbs)

MCTOW (lbs)

Ag Category (lbs)

G limit (normal cat)

Max % Pt 137 Weight (lbs)

Engine 5 Min HP MCP Power loading (lbs/HP)

Power Loading AG

Power Loading (Pt137)

Wing Area (Net Sq.Ft)

Wing Loading (MCTOW)

Wing Loading (Pt137)

Hopper (Cu Ft)

Hopper load limit (lbs)

Hopper load limit (lbs) for Graph

Super Capacity

(lbs) 1150g/L

Mass Ratio

(Super)

Vs (Clean) Va Vne (CAS knots)

V cruise (CAS knots)

Rate of Climb (ft/min) MAUW

FU24 (225) 1978 3550 3970 3.8 31 4651 O-470-E 225 225 15.78 17.64 20.67 266 13.35 17.48 25 1600/1850/214 1600 1795 1.122 96 143 114FU24 (240) 1978 3740 4175 3.8 31 4899 O-470-M/N 240 240 15.58 17.40 20.41 266 14.06 18.42 25 1600/1850/214 1600 1795 1.122 96 143 114FU 24 (250) 1978 3830 4280 3.8 31 5017 IO-470-G 250 250 15.32 17.12 20.07 266 14.40 18.86 25 1600/1850/214 1600 1795 1.122 96 143 114FU24 (260) 2000 3900 4360 3.8 31 5109 IO-470-D 260 260 15.00 16.77 19.65 266 14.66 19.21 25 1600/1850/214 1600 1795 1.122 96 143 114FU24(285) 2310 4000 4470 3.8 31 5240 IO-520-A 285 285 14.04 15.68 18.39 266 15.04 19.70 25 1600/1850/214 1600 1795 1.122 55/57 96 143 114FU24(300) 2310 4000 4470 3.8 31 5240 IO-520-F 285 300 14.04 15.68 18.39 266 15.04 19.70 37 1600/1850/214 1850 2657 1.436 55/57 96 143 114FU24(310) 2175 4000 4470 3.8 31 5240 GIO-470-A 310 310 12.90 14.42 16.90 266 15.04 19.70 37 1600/1850/214 1850 2657 1.436 55/57 96 143 114FU24-1060 2600 4860 5450 3.8 31 6367 PT6A-20 500 500 9.72 10.90 12.73 266 18.27 23.93 37 3000 3000 2657 0.886 63 115 168 134FU24-950 (37) 2800 4860 5430 3.8 31 6367 IO-720-A1A 400 400 12.15 13.58 15.92 266 18.27 23.93 37 2140 2140 2657 1.242 63 116 145 116FU24 -950/954/M 2800 4860 5430 3.8 31 6367 IO-720-A1A 400 400 12.15 13.58 15.92 266 18.27 23.93 43 2800 2800 3088 1.103 63 116 145 116FU24-950 FC 3012 4860 5430 3.8 31 6367 PT6A-15AG 550 392 8.84 9.87 11.58 266 18.27 23.93 66 4100 3555 4740 1.333 116 145 116FU24-950TCL 3030 4860 5430 3.8 31 6366 M601D-11NZ 550 430 8.84 9.87 11.57 266 18.27 23.93 66 2800 2800 4740 1.693 61 116 145 116 1320/115008-600 LTP 2956 6450 7000 3.56 28 8256 LTP101-600A-1A 599 565 10.77 11.69 13.78 266 24.25 31.04 66 4100 4100 4740 1.156 67 124 173 137 77008-600 PT6 2956 6450 7000 3.56 28 8256 PT6A-34AG 750 633 8.60 9.33 11.01 266 24.25 31.04 66 4100 4100 4740 1.156 67 124 173 137 770750XL AG 3825 7500 7500 3.47 26 9450 PT6A-34AG 750 633 10.00 10.00 12.60 267.8 28.01 35.29 93 4410 4410 6679 1.514 69 132 171 141 1067

0AT-402A 4000 6000 7000 3.8 31 7860 PT6A-11 550 550 10.91 12.73 14.29 306 19.61 25.69 53.4 3250 3250 3835 1.180 65 122 122/153 122 1170AT-402B 4000 6000 7860 3.8 31 7860 PT6A-15 680 680 8.82 11.56 11.56 306 19.61 25.69 53.4 3250 3250 3835 1.180 65 122 122/153 122 1170AT-402B 4000 7000 7860 3.8 31 9170 PT-6A-15,27,34 680 680 10.29 11.55882 13.49 312 22.44 29.39 53.4 3250 3250 3835 1.180 122 122 122 1630AT-502B 4100 8000 9400 3.8 31 10480 PT6A-34,36 750 750 10.67 12.53333 13.97 312 25.64 33.59 66.8 3250 3250 4797 1.476AT-502A 4100 8000 10480 3.8 31 10480 PT6A-45 1100 750 7.27 9.527273 9.53 312 25.64 33.59 66.8 4100 4100 4797 1.170

0 0GA-200 1724 2900 3796 3.8 31 3799 IO-540A1D5 250 250 11.60 15.184 15.20 192.4 15.07 19.75 28.25 1865 1865 2029 1.088 53 105 135 108 900GA-200C 1874 3360 4400 3.8 31 4401.6 IO-540K 300 300 11.20 14.66667 14.67 211 15.92 20.86 28.25 2315 2315 2029 0.876 56 113 141 113 950

0 0Ayres S2R-T34 3600 6000 7200 3.8 31 7860 PT6-34AG 750 700 8.00 9.6 10.48 326 18.40 24.11 66.25 4638 4638 4758 1.026 77 109 138 109

0 0Cessna 152 1160 1640 O-235 118 118 13.90 0 0.00 0 0Cessna A188 1926 3802 4000 3.8 31 4981 IO-520-D 300 285 12.67 13.33 16.60 202 18.82178 24.66 26.8 1670 1670 1925 1.152 56 101 157 125PA-25 1556 2899 2899 3.8 31 3798 O-540 235 235 12.34 12.34 16.16 183 15.84153 20.75 20 1200 1200 1436 1.197

0 0Ag-Cat G-164A 2455 4500 4500 4.2 35 6075 R-985-AN1 550 500 8.18 8.18 11.05 328 13.72 18.52 53.4 2000 2000 3835 1.917 58 102 128 113Ag-Cat 'FatCat' 2455 4500 4.2 35 6075 M601E-11 751 657 5.99 8.09 328 13.72 18.52 53.4 2000 2000 3835 1.917 68 750Zlin Z-137T 2900 5566 3.7 30 7236 M601Z 600 600 9.28 0.00 12.06 392 14.20 18.46 35 1984 1984 2513 1.267Zlin Z-37T 2756 5566 3.7 30 7236 M601Z 600 600 9.28 0.00 12.06 392 14.20 18.46 35 1984 1984 2513 1.267 118 103

0 #DIV/0!AirTruk PL-12 1850 3800 4090 3.8 31 4978 IO-540K 300 300 12.67 13.63 16.59 253 15.01976 19.68 26.8 0 1925 #DIV/0! 105 105

0 #DIV/0!Beaver 3150 5099 5500 3.8 31 6679.69 P&W R-985 450 450 11.33 12.22 14.84 250 20.396 26.72 35 0 2513 #DIV/0!

Agricultural Aircraft Specifications



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Figure 4.35 Power/Weight Ratio, Agricultural Aircraft Types

The blue bars depict the aircrafts’ power to weight ratio at its maximum certified takeoff weight. The red bars show how the power to weight ratio drops when operated at the agricultural/restricted category weight. The green bars show the aircraft’s power to weight ratio if the provisions of Part 137 appendix B are applied.

Considering the MCTOW (blue bar), the FU24 series show a gradual improvement in power to weight ratio through the various 6 Cylinder piston engines and the 8 Cylinder 400 HP FU24-950 continues this trend. The early turbine powered FU24-1060 is a marked increase in power to weight ratio and the contemporary Flight Care (FU24-950FC) and Turbine Conversions Ltd (TCL) variants are higher again. These contemporary turbine FU24s have a similar power to weight ratio to the early serial numbered AT402B, (MCTOW 6000 lbs ) this is reasonable as the Flight Care version uses the same engine.

If the FU24 turbine versions are operated in accordance with the full extent of Part 137 Appendix B, as shown by the green bars, their power to weight ration drops to close to that of the old piston variants. The AT402B drops also, although its 400 gal hopper18 prevents the full 137 App B load from being carried. With superphosphate the AT402B is volume limited to a weight only 10% more than its MCTOW. The AT502B which is basically a 402, same engine but with a 500 gallon hopper, is certified with a power to weight ratio only slightly less than what the turbine FU24 would achieve if operated at the old ‘Agricultural load’. The wing loading also make an interesting comparison, they are

18 53.4 Cu Ft, 3835lbs if filled with superphosphate, hopper load limit 3250lbs.



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almost the same for the Cresco and Air Tractor, while the piston powered FU24-950 is considerably less at 18.27 lbs/sq ft. The piston powered FU24 had a power loading of 12.15lbs/HP while the turbine FU24 variants are more in line with the turbine powered Cresco and Air Tractors at 8.6 - 10 lbs/HP. Power loading is in effect how much weight every unit of engine power (HP) has to lift. When the power loading is high, i.e. the engine has a lot of weight to lift, it needs the assistance of a bigger wing, hence a lower wing loading. Alternatively you can use the wing to carry a heavier load, increasing the wing loading, but you’ll need more power to keep that wing flying, hence the power loading goes down. They are inversely proportional.

This is also useful when considering the effect of turbine conversions. Both of the turbine conversions have up to 550HP available. As the aircraft operating weight was not increased, the result is a large improvement in the power to weight ratio. The turbine FU24 conversions have a power to weight ratio almost equal to the PT-6 powered Cresco.

The Cresco was originally produced with the 600 HP Lycoming LTP-101 turbine, although most Crescos produced were the later version with the 750 HP Pratt &Whitney PT6-34AG. The graph show both variants of Cresco, the LTP-101 version having the lower power to weight ratio.

The Cessna 152 was added to this table for two reasons. Firstly it provided the author and readers with a known comparison. Secondly the agricultural aircraft returns have consistently featured a small number of hours logged in a Cessna 152. It turns out that over the years some operators have used C152 aircraft for crew training. The use of a C152 is cost effective and as this graph shows the performance of the C152 provides a conservative estimate of the performance of a fully Part 137 loaded Cresco. In short if you can’t get up the valley in the C152, don’t take a loaded Cresco there without your hand on the dump handle.

Structural Weight Ratio The predominance of Pacific Aerospace products is largely based on their exceptional performance. Their performance is not exceptional in traditional terms such as speed or range, but they are world leading in the weight lifting ability or more particularly their ratio of maximum certified takeoff weight (MCTOW) to empty weight. MCTOW includes payload, fuel and crew, empty weight is the weight of the aircraft ready for service but without fuel or crew. This ratio is one that the designer strives to improve as it represent a measure of structural efficiency. The FU24 and its optimised derivatives the Cresco and 750 XL have achieved a remarkably high ratio of maximum all up weight to empty weight. Note that the inverse of this ratio can be read as a measure of the aircraft’s ruggedness, and the comparatively light structural weight of the PAC products should be balanced against perceptions they are “built like brick outhouses”. The design has in fact been carefully optimised for structural efficiency.



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Figure 4.36

The light structural weight of the FU24 and particularly the derivative 08-600 Cresco and 750XL is due to some interesting design features which intentionally minimise structural weight. An example of this is a comparison of the FU24 wing structure, with the more conventional Cessna Agwagon Wing. Note the FU24 has only three full ribs compared with 12 in the Cessna, figures 4.37 and 4.38 refer.



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Figure 4.37

Figure 4.38



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The detail design of the Pacific Aerospace series incorporates features to minimise structural weight. One of these measures is a reduction the number of parts, which has the added advantage of reducing manufacture and assembly costs. Low structural weight enhances the aircraft’s economic performance, if the wing has less aircraft structural weight to lift it can carry a greater payload. The low structural weight doesn’t mean they are less strong, as the aircraft have met certification requirements. However the structure of the these aircraft demands careful attention to maintenance as the failure of any one component is relatively more serious than in conventional designs. Further explanation of this design philosophy and a comparison of the FU24 vertical stabiliser with other aircraft designs is contained in Annex M.

Conclusion 4.8 Relative to other common agricultural aircraft, Pacific Aerospace aircraft have a low structural weight in comparison to their MCTOW. While this is not unsafe, it highlights the need for the structure to be maintained to a high standard.



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Chapter 5 - Unreported Incidents Scope item 4: “To conduct a study in association with NZ agricultural aviation operators and pilots to further quantify possible unreported incidents, occurrences, defects and structural fatigue.”

There have been suggestions that industry is not reporting safety occurrences to the CAA as diligently as it used to. While the CAA does not expect all defects and incidents to be reported, aircraft safety would be affected if reporting significantly decreased. Under reporting is not necessarily due to dishonesty or non-compliance, some under reporting inevitably occurs due to misunderstandings or pressure of work. Nonetheless, a decrease in reports as a percentage of actual occurrences would signal serious problems for CAA and the industry.

The April 2007 letter to industry stakeholders asked them whether they were aware of any incidents that were not reported to the CAA. This approach met with limited success, partly because respondents were not sure which occurrences the CAA knew about. As a result, the occurrence collation exercise described above was initiated. Once the list of known occurrences was compiled, it was sent to leading industry stakeholders for comment.

Several responses were received and significant ones are included below. Due to elapsed time and scarce details, these reports proved difficult to follow up. However, they are similar in nature to the reported defects. For example, in the case of the Walter Engine failure, investigation of this event may lead to another failure being recorded but as can be seen the failure rate is already well in excess of the piston engine rate, little new information is obtained.. These occurrences are further examples of known issues - Walter engine reliability, fin LE skin cracks, inadequate maintenance program. The noteworthy exception is the last one concerning rear fuselage skin cracking. There are no reports of this defect in the CAA database and yet there is an AD, DCA/FU24/129 dating from 1958 that suggests it was once a problem that required an inspection of this area. ( Ann aircraft engineer, experienced on FU24 aircraft participated in the recovery of ZK-DZG from the forest near Whangarei. He recounted how during the recovery operation the skin of the upper rear fuselage tore easily by hand. While the aircraft was already extensively damaged, his assessment was that the material, ‘felt’ quite different from the similar material on the lower rear fuselage. The lower fuselage skins had been replaced due to corrosion and damage from rough surfaces, and so were newer than the upper fuselage skins that he referred to. While unquantifiable, these were the observations of an engineer with many years experience in aircraft sheet metal work.)

The following email responses have been rendered anonymous by removal of references to companies, individuals, aircraft registrations, locations or dates. Nonetheless they reinforce the assumption that not all occurrences are reported to the CAA. Therefore, the CAA must act on the information it does receive, as one report implies more than one incident.

Email 1 We think there is an engine failure with {deleted} that is not on your list. {deleted} should be able to help with the date. {deleted} was on takeoff and he had a complete engine failure. He was very quick thinking and did not dump, which kept the aeroplane on the ground. He was able to brake hard but still ended up in a line of trees. The engine was totally destroyed.



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Email 2 It has been brought to my attention by a another concerned engineer that {deleted} are carrying out repairs to the side fuselage skins due to cracking on the frame which holds the fwd fin attachment. ZK-{deleted} has patches on both sides just above where the flat side skin meets the curved belly skins. From a distance they appear to be about 4 to 6 inches across. To the best of my knowledge the repair manual allows very minor repairs only and refers the operator to the manufacturer for anything that may affect integrity of structure. In field AC43 type repairs are not generally applicable to the FU-25-950 series. This hardening of skins and fracturing is caused by high operating cycles and loads. Repair will add stiffening but most likely increase hardening and fatigue in the adjacent panel. The 950 already has an inspection for cracking of skins one frame behind the small cargo door. I have been caught out with not finding cracks when one skin cracked all the way down the end rivets because the crack stayed in line with the rivets and did not show until we stripped the aircraft for overhaul. The pilot had reported that the aircraft felt “mushy” in a turn. On the same aircraft severe fretting of frames and interlocked skins was not evident until the fuselage was completely dismantled. Most of the skins and all the frames needed to be replaced. The frames are much softer material than the skins. This was the only skin cracking normally noted on the 950’s. Email 3 This email potentially sensitive, and was submitted in confidence-It described a further defect to the leading edge of a FU24 that was reported by the pilot but not reported to the CAA although the fin was subsequently removed from the aircraft and a replacement fitted. Email 4 Monday last week I was in {deleted} for a scheduled 100hr hour maintenance. The previous week at 100hrs I had a fin inspection done by the engineers at {deleted} and was told all was fine. A week later at xxx hrs they replaced the fin as they found a crack in it. I am not sure where the crack was as they did not tell me. I found out second hand from an engineer on the hanger floor. I presume they will forward an incident report to CAA. Do they still want to extend fin inspections ( yea right ). The fin was an unmodified one that was 26hrs from last inspection!!! Email 5 Regarding 150 hr checks on Ag aircraft. We , and I speak for a few of the pilots in {deleted} do not agree with or want 150 hr checks. They have been slowly and very cunningly adopted by the management over a period of time. We have voiced concerns about this to management to no avail. As I understand the fin failure on {deleted} aircraft occurred approx 120 hrs from last inspection. Sure the Turbine engine does not require as much maintenance as the old 400hp piston but the airframe is working one hell of a lot harder. I do not rate any testing done by {deleted} as creditable as it is done in house with what I call the “yes” men. All testing should be carried out by independent assessors. As I understand it CAM 8 gives the guidelines to operate above the manufacturers weight limits, with the proviso that the pilot observes certain speed limits. Given that we must TRUST the PILOT to adhere to those limits. Given that the aircraft is GOING to be operated ABOVE the manufacturers weight limits ( if there is room in the hopper it is usually filled ) what are the maintenance issues that can arise. Q. Instead of 100hr checks, do we have 50hr checks? ( or do we extend to 150hr checks !!! ) Q. Do we have terminating C of A, eg 4 yearly. ( Like the old system ) Q. Do we have lifed components ? ( eg Zlin Z 37 and Z137 ) Surely if we are exploring and operating in areas above what the manufacturer has tested and certified there MUST be EXTRA maintenance REQUIRED and ORDERED to be done other than just trusting the pilot to adhere to a speed restriction. Management must shoulder some of the cost in extra maintenance required or we will see more structural failures and lifes lost, and I for one do not want to lose any more work mates for the sake of the mighty dollar.



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All we ask for is a safe work environment, not to be asked to carry weights far in excess of what some of these very old airframes were designed for. There are some of the new generation Ag pilot out there who were not even born when the tail fell off the first Cresco and we need to look after them as well. There are other issues with these Hotrods that I would like to talk with you about, and I look forward to a meeting with you

The opinion was expressed during the survey that the overall level of reporting to the CAA had dropped off in recent years and this was masking the true size of the problem. The Review did not find any evidence of this, despite the small number of significant defects noted above. To quantify this, the recorded occurrences for the FU24 were totalled up for each year on record and the following graph was produced. It shows that he reported occurrences per year for the FU24 have increased markedly in recent years. In the period 94/2007 at least, the hours flown by these aircraft has been steadily decreasing. This result could be seen as an increase in occurrences for the FU24 as they age, but certainly it does not support the assertion that the rate of occurrence reporting to the CAA has sharply declined.

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Figure 5.1

Summary and Conclusion While the CAA can rely on receiving only a percentage of the true number of maintenance occurrences, it is advised of a significant number of them. Furthermore, the significant defects and the unreported occurrences are similar to the reported occurrences. As such they do not appear to affect the overall pattern.



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Conclusion 5.0 Industry actively reports incidents of defects to the CAA. There is no evidence to suggest that overall reporting rates have declined significantly.



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Chapter 6 - Turbine Conversions

Scope item 5: “Consider the airworthiness and operational implications of operating modified agricultural aircraft where old airframes are being fitted with more powerful turbine engines.”

Introduction This requirement came from anecdotal evidence that the turbine converted FU24 aircraft were suffering a high rate of engine airframe and operational incidents.

Data Analysis The mail out survey of industry views indicated that 67% of respondents questioned the airworthiness of the FU24 turbine conversions. In addition, the investigation of the fatal accident involving ZK-DZG prompted a ministerial enquiry to examine the relative accident and defect rates of the FU24 and its turbine variants. In response a comparison of accident and rates was conducted by the SAU and is summarised below.

Piston engined accident rate Turbine engined accident rate95 0.66326496 0.291646 097 0.179404 098 0.121515 099 0.180698 0

2000 0.368156 02001 0.475584 02002 0.245836 0.1660092003 0.211809 0.8361152004 0.051354 0.0787642005 0.10018 0.2768712006 0.117254 0

2007 (1st 1/2 year) 0.079706 0.075191

total: Overall 0.237173 0.17359

Piston rate since 1998 (when turb introduced)0.150637

Figure 6.1

The overall accident rate for piston engine FU24 aircraft between 1995 and the first half of 2007 was 0.237, which is higher than the rate for turbine powered FU24 in the same period. However, considering that the turbine powered FU24 were not developed until 1998 and significant numbers entered service in 2001, a comparison between the rate between 1998 and 2007 is noteworthy g. The piston rate is 0.151 or less than the 0.174 recorded by the turbine variants when compared over the same operating period.

This accident rate data is more clearly understood from the following graph. A three-year moving average line has been added to compensate for the initial spike in the turbine accident rate, which was due to certain accidents occurring during a period in which a



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small number of aircraft had been converted and reported hours were minimal. The early accidents distorted the ‘per flying hour’ statistic. Nonetheless by 2005 where the number of aircraft of each engine type approaches parity, the turbine aircraft accident rate remains slightly above the piston aircraft rate.

0

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95 96 97 98 99 2000 2001 2002 2003 2004 2005 2006 2007 (1st 1/2 year)

FU-24 Accidents per 1000 hoursPiston engined accident rate

Turbine engined accident rate

3 per. Mov. Avg. (Piston engined accident rate)

3 per. Mov. Avg. (Turbine engined accident rate)

Figure 6.2

Accident data is sporadic due to the infrequent occurrence of accidents within a given fleet (total size approx 50 aircraft). Defects by comparison happen far more often than accidents, and are more useful for airworthiness analysis purposes. The following graph shows the rate of occurrence of defects, engine and airframe combined for the piston powered and turbine converted FU24 aircraft.



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0

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95 96 97 98 99 2000 2001 2002 2003 2004 2005 2006 2007 (1st 1/2 year)

FU24 Defects per 1000 flying hours

Piston Def Rate

Tur Def Rate

3 per. Mov. Avg. (Piston Def Rate)

3 per. Mov. Avg. (Tur Def Rate)

Figure 6.3

The turbine-powered aircraft have sustained a higher rate of reported defects since their introduction between 1998 and 2000. This is an unexpected result as the airframes are unchanged aft of the firewall. These results include engine defects, and the Walter engine did record a number of failures. Nonetheless it is unexpected that conversion from a piston engine to a turbine would produce an overall decrease in the reliability of the aircraft, as generally turbine engines are more reliable and less maintenance intensive than piston engines. The Walter conversion STC also suffered from a number of engine mount failures due to poor detail design and incorrect installation which is shown by the engine mount defect curve in Chapter 4 Section 2. While the high initial defect rate can be due to the teething troubles of a new design, after 9 years of service the combined defect rate of turbine converted aircraft remains higher than the unconverted aircraft. An essential assumption in the certification of the turbine conversion STC was that the airframe limits (maximum flying speed and maximum take-off weight) and the resulting airframe stress levels would not change. A plausible explanation for the unexpected increase in airframe defects follows.

In practice, the lower thrust developed by the 400 hp piston engine compared to the 600 hp turbine, meant that often the load the aircraft could take-off with was less than the maximum limit due to the size of the airstrip, density altitude and other factors. With the extra thrust, turbine powered aircraft could carry higher loads (closer to the upper limit) more often. This would have the effect of raising the ‘average’ load carried by the turbine-powered aircraft, while still observing the limitations. This is a possible cause of the increased rate of defects experienced by the turbine converted FU24 aircraft.

Turbine Conversions Considerations Converting a piston-powered aircraft to a turbine is a major and expensive exercise. The turbine engine alone can cost $250,000-$500 000, compared to $75,000-$100,000 for an



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overhauled IO-720. So there have to be good economic reasons to do so. These reasons include:

• Increasing the aircraft’s productivity and usefulness due to the expected greater reliability of the turbine.

• Better exploitation of the airframe’s performance potential due to the turbine’s ability to keep generating rated thrust in ‘hot-high’ conditions (applies to flat rated turbines only)

• Extend the aircraft’s service life when the piston engine is becoming obsolete and difficult to maintain. (This is particularly pertinent to radial engines, but the Lycoming IO-720 was never a large production engine and has become relatively expensive to overhaul.)

To overcome the cost of installing the turbine engine instead of a replacement piston, the combined cost must be less than the alternative, which is to retire the airframe and purchase a newer turbine (or piston) powered aircraft. Turbine conversions necessarily extend the service life of the airframe of a converted aircraft. If a used airframe continues in service, the rate of airframe defects may not change, but is more likely increase due to:

• Increasing age

• Increase in utilisation due to the economics of operating a turbine

• Increased ‘average load’ as described above.

The first cause arises because re-engined airframes stay in service longer. A rise in defects recorded for that airframe type is attributable to longer service, rather than any special detrimental influence of the engine change. However in the case of the FU24, which is the major re-engined’ type in New Zealand, the increased defect rate relative to its piston engine contemporaries suggests that the other two causes are present.

Therefore, before approving a turbine conversion, it would be desirable for the CAA to consider the above effects to determine whether the conversion is likely to have adverse effects on the airframe to which the new engine is fitted. To do this, the CAA would require an accurate information on the airframe type’s overall service history. Before the Review, that information was not readily available.

Regulatory Requirements for Turbine Conversions Approval of turbine engine conversions in made in New Zealand under CAR Part 21 sub part E. CAR 21.505 defines the applicable certification basis for an STC. This rule defines the certification requirements for all aircraft design changes (modifications, repairs and STCs). By this circuitous route, designed for maximum efficiency in writing the rule but not clarity of purpose, the certification basis for the conversion can be one of the FAA requirements such as FAR 23, but need not be later than the certification basis of the basic aeroplane. The rationale for this is sound, when modifying an aircraft the modified design should be no less safe than it was before, but there is sometimes little to be gained by raising the certification standard. The classic example is fitting fireproof seat covers to an old aircraft covered in flammable fabric, clearly not a worthwhile safety improvement.



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However by tying the repair modification and STC certification requirements together there is a potential problem.

The problem is that the scope of ‘design changes’ encompassed by the categories repair-modification-STC’ is very large. Even within the category of STC, the design change can be as small as fitting an extra bracket to attach a shoulder harness, up to turbine engine conversions or re-winging. Hence the rule architecture used where all roads lead to one place is elegant for keeping the rule concise but tends to produce a one size fits none policy.

Within the existing requirements of CAR 21.505 (a) and (b) there does not seem to be scope to apply a later (higher) certification basis to an airframe whose life is being extended by STC. However, the rules governing eligibility for an STC, CAR 21.119 (b), states:

(b) A certificate issued by the Director under this Subpart may be subject to conditions as the Director considers appropriate in each particular case.

This appear to enable the Director to impose additional conditions, including requirements from a later certification basis, in addition to the basic certification requirements. Therefore it should be possible to amend the STC approval procedures19 to ensure that major STCs require an examination of the airframe type’s history to ensure that existing concerns are adequately addressed, even though those aspects of the design may be unchanged since approval under the original certification basis.

Some care is needed in the application of this policy, as the airframe may have existing safety concerns that are not a result of the proposed STC. Nonetheless in the case of a major STC that significantly increase the utility of the aircraft it is in the interests of aviation safety to address any outstanding issues.

Ideally, the original equipment manufacturer (OEM) would have addressed these safety concerns. In practice, as fleet numbers of aging and obsolete airframe types decrease, active management of the types’ continued airworthiness becomes less urgent for both the OEM and the regulatory authority. The CAA must use its limited resources to best effect. For example, if the safety of the De Havilland Austers in New Zealand were doubled, the overall safety of GA flying in New Zealand would increase marginally. It is assumed that these problems are small and decreasing with time. This concept underlies the regulatory practice of ‘grandfathering’, which excuses older aircraft from meeting the certain safety standards of new aircraft: for example, while new aircraft may require seatbelts rated to 16G, existing aircraft may continue in service with their original seatbelts good for 8G. It is not that the newer aircraft are likely to crash any harder, it is a pragmatic assumption that the older aircraft population will gradually retire and be replaced by increasing numbers of later aircraft, producing an overall rise in the ‘average’ level of safety, without any further intervention by the regulator.

The grandfathering policy becomes questionable when the assumed natural attrition is halted or reversed. An STC to install a reliable new engine or other equipment, such as spar replacement, can have this effect; they prolong the useful life of an otherwise

19 A CAA internal procedure since STC can only be approved by CAA and not delegation holders



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undesirable or uneconomic airframe. For these types of STC, some analysis of past service history is desirable. If such an analysis were to reveal an existing weakness in the design, particularly in comparison to the state of the art at time of STC application, it is arguable that the Director may invoke CAR 21.119(b) to require that they be addressed. Alternatively, if legal opinion is that the issue does not fall within the scope of CAR 21.119 (b), then it adds further weight to the call for a ‘changed product rule’. Conclusions 6.3 , 6.4 and 6.5 at the end of this chapter relate to the above section.

Comparison of STC and TC Amendment Rules If the provisions of Part 21 Subpart E Concerning Supplementary Type certificates are compared with Subpart D concerning changes to Type Certificates an interesting point stands out. 21.95 relates to the amendment of an aircraft type certificates by the holder of the type certificate, who is usually the OEM. 21.95 states that if the TC holder seeks to modify the design in a significant way then a new type certificate must be applied for, with an updated certification basis based on the date of application. The design changes listed as significant include the “change of nature of propulsive system”. This means that if for example an aircraft manufacturer increased the piston engine capacity from 320 cubic inches to 360 cubic inches, the type certificate can be amended to include the new model. If the manufacture elects to change the propulsive system, for example create the Jet Provost from the Piston Provost, then a new type certificate and certification basis is required. There are obvious reasons for this. In the case of turbine conversions where a turbine engine is used to drive the propeller, the ‘means of propulsion’ i.e the propeller is not changed so in accordance with the rules a turboprop model may be added as an amendment to an existing piston engined aircraft type certificate. In practice, considering the two turbine conversions proposed by Pacific Aerospace namely the development of the Cresco from the FU24 and the turbine engined CT4, CAA advised the original certification basis of the airframe would not be acceptable.

The Cresco was certified in 1983 to FAR 23, yet the Turbine Conversion of the FU24 per STC 98/21E/15 approved 15 years later retained the 1954 certification basis of CAR 3 for the airframe. The turbine engine installation and associated ‘new’ parts were certified to FAR 32 at a contemporary amendment status. The reason for this was that both of the manufacturer proposed turbine derivatives used the extra power of the turbine engine to increase the aircraft’s weight and speed envelopes. The Walter turbine conversion STC was approved on the condition there would be no change to the aircraft’s maximum weight or maximum speed and the corresponding loads, so the original certification basis would suffice for the airframe. Nonetheless a comparison of the manufacturer and third party turbine conversion projects illustrates the importance of the CAA maintaining consistent policies.

Turbine FU24 Assumptions and Outcomes The composite certification basis of the Turbine Conversions Ltd STC 98/21E/15 has been criticised for using a composite certification basis that relied on the original aircraft certification basis. However the certification basis was acceptable because it was:

• Within the requirements of Part 21 Subpart E.

• The STC was approved on a ‘no significant change’ assumption.



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This assumption was that the aircraft’s flight envelope and certified take-off weight would remain unchanged by the STC. Although more engine power was available, pilot would throttle back on reaching the existing speed limitations. As the certified weight limit remained the same the airframe should not see any overall increase in loads. Service history to date at those loads had been satisfactory, (without a trend analysis), so flying at the same speeds and weights should have no detrimental effect.

What this assumption overlooked was that the introduction of Part 137 in 1994 had extended weight increase privileges to the FU24 that it was never entitled to. Because of the way the curve in Appendix B works the FU24 was eligible for a 31% overload. The Cresco was permitted 28%, although, as detailed in Chapter 4, no substantiation of the structure in accordance with CAM 8 had been performed for either aircraft. The contemporary American aircraft such as the AirTractor 402A were also permitted to operate at up to 31% above the MCTOW. The difference is that they had been certified to this weight in accordance with CAM 8 (or FAR 23). In the case of the AT402B, the FAA certified restricted category weight is listed in the type certificate data sheet, along with associated life limitations, undercarriage modifications and speed limitations. In this sense they were entitled to operate at the Part 137 Appendix B weight, while the FU24 and Cresco were not.

A 31% increase over the MCTOW puts considerable strain on an aircraft. At MCTOW, the payload (includes pilot and fuel) of an original FU24-950 is about 40% of the MCTOW. (Refer to the aircraft comparisons table of Chapter 4 Section 3.) The addition of the further 31%, as sanctioned by Part 137 Appendix B, permits a total payload of 175% of the original payload. It is unlikely that the designer of the original aircraft would have installed an engine capable of lifting 175% of the design payload. This is the case for the piston engine FU24. While Part 137 allows the weight to be increased beyond the previous 12% overload, a 400 hp engine is not sufficiently powerful to exploit the full 31% in normal agricultural operations.

The other limiting factor to exploiting the provisions of Part 137 was the simple fact that while the existing 44 cu ft hopper could accommodate up to 3294 lbs of superphosphate which was just equal to the Part 137 allowable load. However the 44 Cu ft hopper could hold only 2114lbs of the less dense urea, or 18.8% less than the Part 137 allowable urea capacity. To overcome this problem, the FU24 conversion to Pratt & Whitney PT6 turbine power took the opportunity to fit a new 66 cu ft hopper. This was justified on the ‘no change in all up weight’ basis; the extra capacity would only be used for dispensing low-density materials such as urea.

And here is where the assumption of no change to flight weight and speed envelope was undermined by the previous application of the Part 137 weight increase. The 44cu ft hopper coupled with an engine limited to 550 hp allowed the aircraft to operate with the full Part 137 weight increase. No substantiation at the full Part 137 weight was required because that had in theory already been approved by Part 137 and demonstrated by four years of successful operations at that weight.20 However, operations at the full Part 137 weight with the 44 Cu Ft hopper were unlikely for aircraft powered by piston engines.

20 This discussion explains the changes of slope in the FU24 undercarriage defect curves, in Chapter 4 Section 2. There is an increase post 1994 and a much more pronounced increase after 2001 when the turbines entered service.



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Effect of the Turbine FU24 on Agricultural Aircraft Industry The net effect of the FU24 turbine conversion was the availability of an aircraft that could carry more than a GA200, and at least 75% as much as a Cresco or Air Tractor for less than 50% of the cost of a Cresco. (Figures for PT6 stretched FU24 and assuming ownership of original donor airframe). The resulting aircraft although similar in performance to a Cresco would still be an older aircraft and could not be expected to have the same reliability or economic life remaining as a new Cresco. This raised the question in the authors mind, why sink money into a ‘partly used almost Cresco’? The answer given by one operator was that the turbine conversions represented a halfway step to enable owners of piston powered FU24s to improve the productivity of their aircraft. This would allow them to accumulate sufficient capital to purchase a Cresco as the eventual replacement for the FU24.

Unfortunately for operators with this intention Pacific Aerospace has since ceased production of the Cresco. Several industry sources allege that the development of the various turbine powered FU24s led to closure of the Cresco production line as well as the cancellation of orders for the GA200C, which had been certified in Australia to FAR 23 in 1998.

To verify these assertions the CAA register of aircraft was examined. By accounting for the initial registrations and deregistration the following graph was produced. The graph shows the total number of the aircraft types in question on the NZ register.

Figure 6.4



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The upper blue line shows the number of Crescos produced and registered in New Zealand steadily climbing in the early 1990s. After 1997 the number drops and fluctuates; this represents aircraft produced and then deregistered for export. The numbers increase again after 2001, but by 2002, production at PAC effectively finishes; the last three fluctuations represent aircraft produced for export as parachute machines.

The middle red line shows GA200s being added to the New Zealand fleet steadily until about 2000 when a few are exported and some of those remaining in New Zealand are sold to gliding clubs. None have been imported since 2003.

The larger and more expensive Air Tractor data is less clear. One was exported causing a small drop in numbers post 1997.21

Because the CAA database was not configured to provide this data directly, the SAU adapted a query tool. (Anomalies in the way the registration data was entered should be noted.) Within the limitations of the analysis method, the assertion that the development of the turbine FU24 announced in 1998 and completed in 2002, caused a reduction in the adoption of newer aircraft types, cannot be dismissed.

While the CAA cannot and should not decline the approval of a design change to protect the commercial position of existing participants, the importance of applying consistent policies and considering their likely wider effects is obvious.

Chapter 6 Conclusions - Turbine Conversions

Conclusion 6.1 Since their introduction, the turbine-powered variants of the FU24 have suffered a slightly higher accident rate than the piston-powered variants.

Conclusion 6.2 The defect rate per flying hour of the turbine aircraft has remained higher than the defect rate for piston engine aircraft since their introduction.

Conclusion 6.3 STC approval procedures should include a review of the service history of the airframes to which new engines are fitted for issues that may be exacerbated or revived by the STC.

Conclusion 6.4 CAR 21.119 should be reviewed to determine whether the Director may impose additional conditions on the applicant for an STC if a review of the airframe type’s service history indicates additional conditions would be appropriate.

21 The graph software connects discrete numbers with a line. This implies that the numbers fell gradually from four aircraft to three, although in practice a step change occurred.



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Conclusion 6.5 Consideration should be given to the introduction of a ‘changed product’ rule to clarify the conditions to be imposed on modifications that essentially change the nature of an existing product, such as the change of motive power or restarting production.

Conclusion 6.6 CAA policy relating to Part 21 subpart E regarding the Director’s power to specify the special conditions or later certification basis for extensive STC modifications is not clearly defined. As a result CAA policies regarding amendments to type certificate and approval of STCs may have been inconsistently applied.

Conclusion 6.7 The introduction of Part 137 in 1994 extended privileges to the FU24 (and Cresco) that could not be substantiated. The impact of these privileges was obscured until the more powerful turbine engines were fitted in 2001. In this sense Part 137 undermined the assumptions used to approve the turbine conversion.

Conclusion 6.8 The combined effect of the Part 137 weight increase and the turbine conversions was a sharp increase in aircraft defect rates, particularly evident in the rate of undercarriage failures.

Conclusion 6.9 A further unintended effect of the turbine conversions may have been to halt the introduction of newer aircraft, such as the Cresco, GA200 and possibly the AirTractor.



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Chapter 7 - Certificate of Airworthiness Duration Scope item 6: “Consider the implications of current non-terminating certificates of airworthiness in the agricultural context.( i.e. vs. 4 yearly and 8 yearly rebuilds of days past)”

To understand the reason for this scope item, several pieces of regulatory history need to be considered.

Part 43 and Appendix C Prior to the introduction of Part 43 in 1992, in particular, Part 43 Appendix C, most FU24 aircraft (and other types) were maintained in accordance with maintenance programs developed by operators and approved by the Civil Aviation Department (CAD). Part 43 introduced the option of maintenance in accordance with a generic schedule of inspection items that was included in Part 43 Appendix C. It is not obvious from a contemporary perspective why the CAD decided to move from a proven system of maintenance developed by operators to a generic list of typical aircraft inspection tasks. The intention may have been to to offer the Part 43 Appendix C schedule of maintenance for those aircraft types for which a manufacturer’s or operator’s maintenance program was not available. However, Part 43 only required GA aircraft to comply with the maintenance schedule set out in Appendix C.

Despite the licence offered by Part 43, many experienced maintainers continued with their own versions of the old ‘company schedules’. (Customers appear to have accepted this approach on the grounds of purported reliability.) This approach was legal, as the company schedules were more specific than Appendix C. Therefore, a servicing statement that the aircraft had been “ inspected IAW Part 43 Appendix C” was valid.

Nonetheless, Part 43 Appendix C provided a simpler and lower cost, legal alternative for certain operators. This led to a general decline in the maintenance of certain agricultural aircraft after 1992.

Part 43 Appendix C was widely regarded as inappropriate and was reserved in March 2007.

Non-Terminating Certificates Of Airworthiness Another significant policy change was to move from issuing COAs that terminated after five years, to a system of non-terminating certificates of airworthiness, in 1992. The primary motivation for moving to non-terminating COAs was to reduce the burden on the CAA inspectors. (The CAA currently employs one full time aircraft inspector, although they contract the services of a retired ex-CAA staff member and also use professional engineers from the ACU to issue initial and export COAs. Re-issuing COAs would require substantially more CAA resources.)

While a ‘non-terminating’ COA may imply a lifetime warrant of fitness, the new certificates were accompanied by rule changes that made the non-terminating COA valid only while the aircraft continued to be inspected every 100 hours or annually (in accordance with Part 43 Appendix C) and passed an annual review of airworthiness (ARA). Inspection Authority (IA) holders were required to carry out an ARA and to



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provide an independent check of the aircraft’s servicing records, but not necessarily a physical aircraft inspection.

As the IA’s responsibility was to ensure compliance with Part 43 Appendix C, even when it was contrary to his maintenance experience, the IA could not insist on a more thorough inspection if regulatory requirements had been met. The effect of ARAs was therefore limited by the requirements of Part 43 Appendix C.

For these reasons, industry stakeholders proposed that the CAA should re-introduce terminating COAs, with re-certification being dependent on a CAA inspection. Implicit in this proposal was the understanding that the CAA would make a thorough teardown and overhaul in accordance with one of the old company schedules a pre-requisite for re-issuing the COA.

The April 2007 industry survey asked stakeholders whether they favoured a return to terminating COAs. A majority of respondents said they would. A clear bias between aircraft owners and aircraft pilots was discernible in the response, with most (but not all) of the calls for terminating COAs coming from pilots.

Figure 7.1

CAA representatives met operators from the south of the South Island in June 2007 to discuss the topic of terminating COAs. The South island operators shared three maintenance providers, who had continued with their own variations of the old company schedules (but in compliance with Part 43 Appendix C).

The consensus of the meeting was that re-introducing terminating COAs would have no benefit for those operators and would increase compliance costs. Operators believed that, due to CAA staff constraints, a COA could be re-issued from Wellington, with formal but not substantial validity. Nonetheless, the meeting agreed that maintenance standards in other parts of the country could be improved, and examples of aircraft purchased from other operators were discussed.

Further consensus was reached that, if the intent of re-introducing terminating COAs was to ensure FU24 and other agricultural types received the maintenance they require, the CAA should consider mandating a type-specific maintenance program for agricultural aircraft. It was agreed that this program should not be the original equipment manufacturer



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(OEM) programs, as, in the cases of the FU24 and the Cresco, they were inadequate for agricultural operations. The meeting concluded that the CAA should compare the maintenance programs in use and compile a ‘best industry practice’ maintenance program that should be mandatory for certain agricultural aircraft types.

The CAA representatives suggested that the Agricultural Aircraft Association (AAA) could play a part in collecting and compiling a ‘Best Industry Practice Program’. Representatives of the AAA agreed in principle.

After the meeting, samples of the maintenance programs were collected during visits to other maintenance providers. The CAA holds the OEM program for the FU24. It was confirmed by Pacific Aerospace Ltd (PAC) that the 1978 edition is current. .

Comparison of Maintenance Programs A spreadsheet was used to compare maintenance tasks. By listing maintenance tasks down the page, a column showing the OEM interval for each task could be compared with a column showing each operator’s interval for the same task. In this way, alignment of the maintenance intervals should be immediately apparent.

In practice, this procedure was more complicated than it first appeared. While the OEM program and the operators had used the basic Airline Transport Association (ATA) chapters to organise their programs, within each ATA section, the various inspections were in different order, used different taxonomy, or had additions or omissions relative to the OEM program or each other. For some OEM tasks, no equivalent tasks in the operators programs existed, and, for some operators, programs recorded maintenance tasks that were not included in the OEM program. Despite the use of ATA chapters, variations existed, such as the inclusion of rudder inspections in Chapter 27 – Flight Controls or Chapter 55 – Horizontal and Vertical Stabilizers.

Airworthiness Directives and Service Bulletins The correct treatment of ADs and manufacturers’ service bulletins (SBs) also needs to be considered. It was concluded that it was best to put the SB/AD with the component grouping that it describes. Although these could be listed separately, (and this was the case in one operator’s program) listing them with their functional group highlighted the need in many cases for the OEM program to incorporate the AD (or SB) and thus permit it to be cancelled.

The analogy may be drawn to a crossword puzzle certain ‘boxes’ were left empty but could sometimes be filled in later when the particular maintenance item was discovered elsewhere in the program of interest. In practice, if the CAA were to conduct this alignment exercise, the operator applying for approval of a program could be asked to fill in the apparent blanks.

As a proof of concept, the alignment was performed on the FU24 empennage, using the current (1978) PAC maintenance program and two of the leading maintenance providers’ own programs. An excerpt from this spread sheet is shown in the following Figure:

For quick reference, where concurrence between a program and the OEM program was established, that inspection item was coloured green. Where a gap existed in either the

FU24 Maintenance Program Comparison

requirement Interval SouthAir PhoenixItem Sub item OEM Prog 1 Prog 2 Prog 3Undercarriage Assembly Clean examine 100/200

Torque links Remove examine 200/400/800Torque links Replace bolts 200Torque links attach fitting DCA/FU24/125 100Oleos Change oil. Repressuris 100MLG/NLG Struts Examine attachments 100MLG Attach Bolts Replace bolts (1 of 4) 400/4MLG Axles Magnaflux DCA/FU24/137B 500MLG/NLG bearings regrease 200NLG Steering Torque tube DCA/FU24/127A 100NLG DCA/FU24/142A Examine 10x 100Tyres condition & pressure 100Brakes Discs/pads wear 100Brake System Examine Hoses/lines 100Brake Mst Cyl Condition & fluid level 100Assembly lubricate 100Brake callipers crack Check pins 200

Mainplane External surface Examine 100Control Surfaces Examine 100Control Cables Examine for fraying, flats, tension 100Control Rods/pulleys Examine, free movement 100Fuel tanks Examine conditon /Security 100Fuel tanks Filters DCA/FU24/168 pt 2 100Fuel tanks Drain, remove & clean fiilters ../168 pt 3 12 monthsFuel tanks Examine fillers, gauges, pipelines 100Fairings/tapes examine 100Attachments Inspect 100Aileron Tip Fairings Inspect PACSB/FU/078 100

Fuselage External surface Examine 100Internal Surfaces Examine 100Structure Examine 100Firewall Examine for condition/sealing 100Canopy Examine for condition cleanliness 100Flight Controls Examine & Lube 100Flap Torque Tube Examine per DCA/FU24/164 100Flap Horn Assy examine x10 100Flap Horn Assy Crack Check PACSB/FU/089 1000Cockpit Area Clean examine structure 100Flap tube seal boots Examine & Lube 1001st Aid Kit Examine 100Seats & Cushions Examine conditon /Security 100Safety Harness Examine conditon /Security 100Safety Harness Proof load 100?Inertia reel Operate, examine 100Inst & Plumb Examine for Condition 100ASI Lines Blow out, Leak test 100Hopper Examine conditon /Security/sealing 100Jettison Operate, examine, lube 100Hopper Lever Operate examikne lock & detent 100Skin STA240 Examine for cracks DCA/Fu24/129 100Control Cables/rods Examine fraying/binding/freedom 100Batteries Check electrolyte, condition, securtiy 100Electrical Operate 100Fuel System Remove examine Sump tank per DCA/Fu24/132 24/48monthsElevatote trim rod Lubricate at rear Blkhd 100

Empennage Fin/rudder/elevator Examine for condition/distortion/corrosion 50 100 100Tail Cone Remove/clean/examine 100Elevator Examine structure, mass balance, Hinges 50/100 100 100Elevator Lubricate Hinges 50Elevator Trim Tab Control arm Examine per DCA/FU24/135 50 100 100Elevator Trim Jack End play, Seal, Lubricate, operat 100Stabilator Remove 12 months 48 monthsStab Hinges Examine Fuselage fittings 12 months 48 monthsStab Pivot Replace bolts 48 monthsElevator Trim Tab Examine cracks & corrosion 50 48 monthsRudder Bushes Examine, check play, Lubricate 50 100Rudder Check Range of Movement, NLG clear of ground 100 belowRudder Lwr Rib Examine in-situ 100Rudder Remove detach torque tube examine per DCA/FU24/134 12 months 12 months 12monthsRudder Remove for Overhaul 48 monthsRudder Controls Examine, Cables, Pulleys Fairleads, Lubricate, Tension 100 above Fin Remove Fwd Fairing and examine attach fitting per DCA/FU24/172 100 12 months 12 monthsFin LE Inspect DCA/FU24/176 below 100 100Fin Skins Inspect for cracks 100 100LE Protection Inspect for security 100Fin Remove Tip Cap, Inspect Upper ribd for cracks 100Fin Assy Remove, Remove Fin Cap,Inspect Internally & externally for corrosion, cracks wear & damage check

Beacon, wiring48 months

Control Surfaces Operate, Lubrciate, range of movement 100General Aircraft Repaint & reweigh 48 months

IntervalItem Sub item requirement OEM Prog 1 Prog 2Empennage Fin/rudder/elevator Examine for condition/distortion/corrosion 50' 100' 100

Tail Cone Remove/clean/examine 100Stabilator Examine structure, mass balance, check play in Hinges 50/100 100 100Stabilator Lubricate Hinges 50Stab Trim Tab Examine cracks & corrosion 50 100* 48 monthsStab Trim Jack End play, Seal, Lubricate, operat 100Stabilator Remove 12 months 48 monthsStab Hinges Examine Fuselage fittings 12 months 48 monthsStab Pivot Replace bolts 48 monthsRudder Bushes Examine, check play, Lubricate 50 100Rudder Check Range of Movement, NLG clear of ground 100 100*Rudder Lwr Rib Examine in-situ 100Rudder Remove detach torque tube examine per DCA/FU24/134 12 months 12 months 12 monthsRudder Remove for Overhaul 48 monthsRudder Controls Examine, Cables, Pulleys Fairleads, Lubricate, Tension 100 above Fin Remove Fwd Fairing and examine attach fitting per DCA/FU24/172 100 12 months 12 monthsFin LE Inspect DCA/FU24/176 50* 50 50Fin Skins Inspect for cracks 100 100LE Protection Inspect for security 100Fin Remove Tip Cap, Inspect Upper rib for cracks 100 48 months*Fin Assy Remove, Remove Fin Cap,Inspect Internally & externally for corrosion, cracks wear & damage check

Beacon, wiring48 months'

Control Surfaces Operate, Lubrciate, range of movement 50/100/annual 100'General Aircraft Repaint & reweigh 48 months

ConcurrExceedsAbsent

FU24 Maintenance Program Comparison



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OEM or the operator’s program, yellow highlight was applied. Where the intervals of an operator’s program exceeded the OEM requirement, the cell was coloured red.

Green tasks (where agreement is reached) require no further analysis. Yellow boxes (where a task is absent) require more consideration. It is arguable that yellow boxes should be back filled, using the most stringent of the programs as the standard. However, some discretion is required as some maintenance tasks may be unique to a certain operator. For example, an operator conducting geophysical surveys may need to check a certain antenna for security, a task not applicable to standard aircraft. The yellow boxes represent areas where an assessment of the discrepancy needs to be made, and a decision reached.

The red boxes highlight where an operator’s program exceeds the manufacturer’s requirement. In this example, the OEM recommends the horizontal stabiliser be removed every 12 months. Operator 1 apparently never removes it (yellow query) and operator 2 removes it at 48 months, four times the OEM interval. Once again, discretion and judgement is required. The OEM program in this case has not been revised since shortly after the aircraft was certified in 1978. In service, Operator 2’s 48-month interval may have proven to be adequate. It may be more appropriate to revise the OEM program to 48 months, rather than aligning operator 2’s program with what may have been a best guess in 1978.

While painstaking, this method of analysis provides a ready comparison of the OEM and individual operator programs.

Conclusions: Chapter 7

Conclusion 7.1 Although favoured by many industry stakeholders, the reintroduction of terminating COAs is unlikely to raise maintenance standards. It would also increase costs for industry and the burden on the CAA.

Conclusion 7.2 A better means of raising the standard of airworthiness for agricultural aircraft is to recognise them as special purpose machines and require specific maintenance programs.

Conclusion 7.3 Expertise in agricultural aircraft lies with industry, and a comparison of leading industry maintenance programs could lead to the production of a ‘best industry practice’ maintenance program. This would share expertise across the industry and raise overall safety. Such a program, along with relevant ADs and SBs, should be fed back to the OEM, and incorporated into the OEM maintenance program. This would become the reference standard for operator programs approved under 91.607. (This would still allow variation from the OEM program, but with explanations.)

Conclusion 7.4

There is a need to review the approval of maintenance programs for agricultural aircraft. Because of the demanding operations, and their predominance in the New Zealand agricultural industry, priority should be given to the New Zealand type designs



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Chapter 8 - Re-use of Data Plates Scope item 7: “Review NZCAA policy of the re-use of data plates from crashed aircraft.”

The CAA policy on the re-use of dataplates is quite clear, and is contained in Part 21.807. This rule does not permit the re-use of data plates. The rule requires them to remain attached to the original aircraft except in certain circumstances for maintenance. Aircraft damaged in an accident retain their data plate, as it is essentially just another aircraft component. It is important that the data plate remain with the damaged aircraft to establish the identity of the aircraft and provide continuity of its maintenance records should it be restored to an airworthy condition. As such returning the data plate to the CAA in the event of an accident that renders the aircraft unserviceable is counterproductive. In terms of preventing the aircraft being flown it is not much more effective than returning the ignition keys.

What this scope item really intended was to examine a proposal to return data plate to the CAA in the event of an accident, to prevent the aircraft from being operated until the CAA has reassessed its airworthiness. Implicit in this suggestion is that a non-terminating COA is not valid where the aircraft has been substantially damaged. The conditions of a non-terminating COA are that the aircraft be maintained in a condition fit for flight. Immediately after a serious accident, the aircraft is not in condition fit for flight, and so the COA is technically invalid.

A more useful way to achieve the aim would be to leave the data plate on the aircraft wreckage, but return the COA to the CAA for revocation (or to be held in abeyance or some other processes).

The Aircraft Certification Unit consider it would be desirable for aircraft that have been seriously damaged in to have their COA revoked, and reinstated subject to a satisfactory condition inspection by CAA staff. This would not only prove an assurance of airworthiness but also reduce the possibilities for confusion of aircraft records. This is particularly relevant when an aircraft is salvage by replacement of major components such as wings, or fuselages.

The only problem with implementing this policy is providing a clear definition of an accident that requires revocation of the COA. While for major accidents, the case is clear, even a minor landing accident can render the aircraft unfit for further flight. Yet the undercarriage repair may only take a few days and the CAA would not want to have revoke and reissue COA for such cases.

The problem becomes defining the boundary, and then the treatment of boundary cases. The principal thing to avoid is the creation of a climate where reporting of moderate accidents is suppressed to avoid the expense of reissuing the COA.

A possible solution to this is to revoke the COA when an aircraft is ‘written off’ for insurance purposes. The negative financial impact is to some extent balanced by the payout of insurance money to the owner. This has implications for the insurance industry, as the ‘valid’ COA relating to a wrecked aircraft may constitute a large portion of the wreck’s residual value. Further meeting with the insurance industry is needed to determine the way forward.



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Conclusions

Conclusion 8.1 Returning the data plate to the CAA is unlikely to be a practical way of controlling the airworthiness of aircraft rebuilt from wrecks. Revoking the COA for aircraft that are ‘written off’ may be a more effective means.

Conclusion 8.2 The CAA’s ACU, Legal, and GA groups need to consider the legal aspects of revoking the COA for aircraft that are ‘written off’, and liaise with insurance industry.



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Chapter 9 - Industry Operational Issues Scope item 8: “Discuss with Industry broader operational safety concerns such as hopper size, compliance with Limitations, Appendix B Overload provision.”

Introduction This was done in several ways, including a mail out survey, group meetings, and interviews with maintainers, operators, and manufacturers. This section outlines the responses received.

Questionnaire In April 2007, the CAA sent questionnaire form to all agricultural pilots and industry members. A total of 116 surveys were sent out and 29 responses were received. In addition, certain south island pilots and maintainers requested a meeting with the CAA team members.. Another 24 industry members attended the meeting held in the Otago Flying Club in June 2007, which provided further informal responses to the survey.

The survey posed the following questions, which were related to the scope items in the Terms of Reference:

1. Can you provide details of aircraft incidents that should be considered in the review?

2. Should the FU24 Airworthiness Directives be split into separate schedules for the piston and turbine aircraft?

3. Are you aware of any common, re-occurring, or unusual defects affecting the airworthiness of agricultural aircraft?

4. Do you have any firsthand knowledge of any undesirable or unsafe design features or new maintenance issues that have arisen as a result of re-enginning?

5. Do you consider the current system of non-terminating Certificates of airworthiness appropriate for agricultural aircraft?

6. a. How practical is the observance of flight manual limitations as a means of ensuring operational safety?

b. Does the current Appendix B to Part 137 provide adequate guidance in the operation of agricultural aircraft at weights in excess of their maximum certified take-off weight?

c. Are there any other operational issues the CAA should consider to improve the safety of agricultural aircraft operations?

7. Do you believe the safety of agricultural operations could be improved by the adoption of newer technologies?

Although the survey questions were based around the Terms of Reference, they were not well designed for collecting survey responses questions 1, 3 and 6c in particular



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received wide ranging responses that did not lend themselves to statistical presentation. Responses to other five questions are represented below:

No

Yes

No

Yes

No

Yes

50%

42%

8%

137 App B AdequateNo

Yes

Not Sure

33%

67%

0%

Terminating C of ANon term

4 years

8 years

33%

67%

Re -engined issues

78%

22%

Flight Manual Limitations Practical?

27%

73%

Seperate Piston / Turbine ADs

Figure 9.1

Summary of Responses Two thirds of respondents believed there were airworthiness issues with the turbine converted FU24 aircraft. Almost 80% of respondents thought the flight manual limitations were a poor means of ensuring operational safety. This question primarily relates to re-engined aircraft in which the horsepower is increased but the existing airframe speed limitations are relied upon to avoid recertifying the aircraft for the higher speeds that can now be obtained.

Separating the ADs was generally supported, although some good points against this were raised. Keeping them together but rewriting the applicability is probably viable.

50% of respondents thought Part 137 failed to provide adequate guidance for agricultural operations beyond the certified take-off weight. Several other responses, such as, ‘who reads it anyway’ were classified under ‘not sure’.

The two thirds of respondents in favour of a return to terminating COAs was not anticipated , as such move would increase compliance obligations. The reasons for this include the generally poor average condition of agricultural aircraft and a desire by pilots to see owners held to account for this. (Chapter 8 examines this issue in more details and concludes that the airworthiness of aircraft could be raised by tighter CAA control of the maintenance programs.)

The responses to question 3, “are you aware of any common, re-occurring or unusual defects affecting the airworthiness of agricultural aircraft”, are represented below:



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This figure shows that the three leading industry airworthiness concerns, were turbine engines, undercarriage and vertical fins. (These topics have been addressed in detail in Chapter 5 section 2.)

0

1

2

3

4

5

6

7

Airworthiness Concerns

Walter

Spar

Undercarriage

Vertical Stab

Elevator

rear Bulkhead

Engine mounts

R22 spray overload

Bell 206 Maint

Hopper size

Flight Duty Time

Farm Strip Enforcement

Roll Over/cockpit

None

Airworthiness Concerns 29 No Concerns 6

Figure 9.2

Industry Comments Not all of the responses received could be correlated to the specific questions included in the questionnaire. These written responses are presented below. Responses have been made anonymous and are listed in groups against each of the survey the questions, with the question in italics.



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4 Re-engined Aircraft Issues Do you have any firsthand knowledge of any undesirable or unsafe design feature or new maintenance issues that have arisen as a result of re-engining? Fuel system in Walter! Should have at least had a non-return valve between inboard and outboard tanks. Why not have scavenge pumps that scavenge into inboard tanks. Cresco hopper in the Fletcher 2000!! The ability to get 100% Tq out of an engine that’s installed in an airframe where the limit is meant to be 89% Tq No PT6 EX fuel lever can be inadvertently shifted past ground idle to shut-off. If left in ground idle more than 10 minutes pitch cable inner sleeve melts then jams when cold; also oil temp gets very high. As newly converted aircraft, I think these are good agricultural aircraft. However, I believe that, because these aircraft are so easy to operate outside safety parameters, that some years after the original conversion, problems can arise. Eg I would not like to be asked to fly one of these aircraft after it had been operated for several years by pilots who disregard Vno, Va, AUW and hopper weight restrictions. In 2005 I was asked by an Indonesian company to assist in familiarising some of their pilots with their newly acquired PT6 Fletcher EX. Using the NZ comprehensive handling notes, and lengthy written rating exam, I was able to demonstrate that these aircraft need to be operated carefully to give reliable long life.On returning home to NZ, I found that an earlier Walter turbo-prop conversion had crashed near Whangarei killing the pilot and driver. I have been informed that the fin ripped at the front and the fin wrapped around the all-flying tailplane. Perhaps NZ pilots who have mostly operated way outside the envelope need to be encouraged to have a look at the flight manual and the handling notes for these converted Fletchers. No comment, but all re-engined aircraft have more horsepower therefore just watch the load carrying of the airframe. Yes. The excessive nose down pitch in Walter powered FU24’s at slow approach speeds, which gets worse as more flap is applied. No Extending maintenance to 150 hr checks when 1 minute per load is taken off the aircraft could well have flown between 175 - 200 hrs between checks. As noted we operate a FU24 Walter powered Fletcher. This aircraft has always been flown within the design parameters and as a result has required no more maintenance (either scheduled or unscheduled) than any other aircraft I have operated. No - although there is a question of reliability of Walter turbines. How many have failed to reach TBO? Air Services had 4 blow-ups. What happens if there is a fatality because of this - so far lucky. No



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5 Non-terminating Certificates of Airworthiness Do you consider the current system of non-terminating Certificates of Airworthiness appropriate for agricultural aircraft? (Consider the March 2007 revised rule 91.605 which requires maintenance to be carried out in accordance with an approved maintenance programme) No - all aircraft should operate under terminating C of A. This would give all parts finite life Provided the necessary items are covered in the maintenance schedule and when they need to be complied with then don’t see a problem. Yes As a one-aeroplane operator I would prefer the non-terminating C of A, but at times I have seen some pretty rough aircraft around, and maybe a terminating C of A may lift the lower standard. An 8 year C of A is too long. A 4 year C of A would be better. NO. Ag aircraft operate in max loads, hard conditions to believe that everything can be fixed at progressive checks is false (usually by the company operating the aircraft). We need to remember some of these machines are getting close to 50 years old, what other operations within NZ re-use equipment this old and are “legally” allowed to repower, redesign; I can think of none. I have never seen a TK Bedford with 550 odd horsepower delivering 10t of fert to an airstrip. No, there needs to be a finite life to airframes. I personally think inappropriate, regardless of maintenance programs so ag aircraft are flying in what I consider a poor state. As long as it will fly people will fly them. I do believe that we should be looking at a fixed term C of A for Agricultural aircraft. Only non-terminating if outside authority responsible for annual inspections Non-terminating C of A’s are fine. Any maintenance requirement renders the C of A null and void until maintenance is completed and aircraft released to service. Yes No. Should go back to terminating C of A’s - 4 or 5 yr. Present system allows for no financial accountability. Present system open to interpretation by owners and engineers.



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6a Broader Operational Concerns How practical is the observance of flight manual limitations as a means of ensuring operational safety? For example, should the aircraft be fitted with further safety measures such as governors, airspeed warning horns, hopper limiters or weight recording devices? No, we are happy as things are out of flight manual Flight manual limitations don’t help much on the job. What is required is weigh-bridges like at the quarries. Aircraft taxies on, loader fills hopper watching the weight. Weight indicators should be considered - even cockeys can weigh their cattle digitally Not very. It’s not. Should be fitted with weight recording devices. I think in general what limitations that are in the flight manual don’t mean too much to the operator, it is the competition and making money. Agricultural aviation is probably the only sector in NZ aviation where the financial success of the operation depends on the pilot’s performance. With a piston powered aircraft, the pilot, if he wishes, may overload the aircraft - that is fill the hopper to the top. Because of the gross overload the aircraft will not fly very fast, it can’t turn much or pull any ‘G’ so not too much damage can be done to the airframe. High powered turbine aircraft are a different kettle of fish. A pilot can carry a full hopper load of product every take-off day in day out year in year out in almost any conditions. A turbine powered aircraft can exceed Va at MAUW or beyond with only cruise power; lower the nose a few degrees and the aircraft is up to the Vne quick as a flash. I think that management and pilots may need some serious education on the stress on fully or overloaded aircraft. If operators charged a better hourly rate for their aircraft, pilots would not have to push themselves or their aircraft to extreme limits to achieve so-called financial success. Fit further safety measures. If you stick to flight manual limitations in a certified aircraft you should have no problems Not always practical in low level hill terrain. Airspeed warning horn would be a good step in the right direction. It is obviously up to the pilot to observe flight manual limitations. I do not believe we should have to install any additional devices to increase the operational safety of our operation. Tamper-proof flight recorders (F/W and Heli) Tq and temp recording - once made mandatory if the operator refuses to supply data then scrap the engine. These are not really workable in this type of operation I believe. More pilot education would be better.



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6b Broader Operational Concerns Does the current Appendix B to Part 137 provide adequate guidance in the operation of agricultural aircraft at weights in excess of their maximum certified take-off weight? How many pilots actually read this or understand it? No Yes I think it does ? No. Should do away with the ag overload Aircraft should only be loaded to manufacturer’s max take-off weight, not some overload weight plucked from the air. Yes I believe it does. Yes Yes There should be a max load limit to be carried in the hopper (same as trucks). This should be placarded for all to see. Absolute maximum load should be clearly marked for pilot and driver - very vague at the moment.

6c Broader Operational Concerns Are there any other aircraft issues that the CAA should consider to improve the safety of agricultural aircraft operations? I think CAA has done a good job in association with our industry in adopting the Code of Practice. All ag aircraft should have the pilot seated behind the hopper. No Duty time. Too many phone calls = not enough sleep. Roll protection. Pilot duty times need to be addressed. Many of us spend 3-4 hours after a day’s work phoning people for work, filing paper work, etc. It isn’t uncommon for 15-16 hour days. Most maintenance problems are brought about by condition of strips and taxi areas. Safety of the Fletcher cockpit - safety frame as discussed as far back as 1979 - non-survivable in even low speed crash More teeth required to police farm airstrip standards Placing larger hoppers to carry bulky products should not be allowed. Hopper limiters very good idea. Competition amongst companies and pricing is a major point in the safety. Outside your scope probably but pay pilots % revenue or a per tonne basis and it’s pretty easy to work out, bigger load - more $ The Kiwi culture of load it up until it breaks Flight and duty times Recording/reporting defects between inspections Banning all ag ops in R22 helicopters, they were never designed for ag work.



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7 Technological Improvements Do you believe the safety of agricultural operations could be improved by the adoption of newer technologies such as, data recording, engine monitoring devices (HUMS). If so please detail. Yes These new technologies would not help much. The pilot monitors engine parameters constantly as well as rest of the aircraft and will report as soon as he observes something different. No - most safety issues are practical ones - airframe design - loads - speeds not designed for, etc. The fixing of tailplanes on Walters needs to be looked at. I do not think safety would be improved with the addition of newer technologies Yes, definitely. Easier policing of speeds and engine performance parameters Possibly? The recording (accurate) of flight time is one of the most important ways of getting the industry all on the same page. Any a/c that can be over-torqued or boosted should mandatorily have that parameter recorded.



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Other Comments CAA is basically held by the majority of the industry in contempt - they need to establish an enforcement unit like the “CUIC” of the LTSA that isn’t trying to keep the industry coming along and be nice at the same time. They’d only have to jump on a few operators and the rest would be happy to fall into line. None at this time Ag ratings to be endorsed on license. Industry-wide training syllabus. Topdressing and aerial spraying is the most dangerous peace-time flying operation. The reasons are obvious. This industry is almost guilty of accepting serious injury and death as just part of job. The economics point to the fact that a certain size load needs to be carried to make money and this is well above the MAUW. I would say it is common knowledge that we all overload. Only a matter of looking at flight logs. The ag industry seems to have been self governing for too long; how many pilots have been killed and nothing ever happens; very easy to blame someone who is no longer with us, than to find the real cause and fix the problem. I am getting the feeling from the tone of this letter that you are specifically targeting the upgraded Walter and PT6 powered FU24 aircraft. I think if you care to look, that a very high percentage of the maintenance issues involving this particular modification come from a particular operation in the {deleted} area. It is frustrating to me as an operator to have my aircraft branded because of the actions of one or two pilots that flout the flight manual limitations. As {deleted} operators of these aircraft appear to be operating them in accordance with the flight manual and maintenance appears to be carried out to a good standard - there seem to be very few issues. I believe the aircraft modification itself is of a good standard, and so long as the aircraft is operated sensibly and in accordance with the flight manual, that this aircraft can be operated quite safely. Replace u/s parts with new. Recently, {ZK-Deleted) was fitted with a -34 engine which was getting hot in a Cresco for req tq. Engineering decided it would be fine at the de-rated HP; after 50 hours it couldn’t make tq at 550 HP so is parked up for 3 months or more ‘til -11 is overhauled. Yes - I do believe re-introducing 4-5 year C of A for agricultural aircraft would definitely improve safety and keep aircraft in tip-top condition. Should stop old fins falling off - FU24 spars would get a decent check more often and generally the aircraft would present better than today’s aircraft which generally are untidy.

Summary and Conclusions Significant numbers of industry members, including some of the most experienced members, have expressed strong concerns about aspects of agricultural aircraft safety. Conclusion 9.1 The current rule regarding operation beyond MCTOW is not well regarded by aircraft crews Conclusion 9.2 Airworthiness of the FU24 aircraft is a commonly expressed concern.



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Chapter 10- Emerging Technologies Scope item 9: “Consider the available technology to assist the measuring, recording and retrieval of hopper loads.”

Introduction

The intent of this scope item was to determine if improvement in digital technology and load measuring devices would make it practical to require mandatory fitting of hopper load measuring devices to all agricultural aircraft. The reason for this is to provide a means of regulating the industry to prevent dangerous overloading by providing a record of the load on each flight.

A full discussion of digital load measuring technology is an engineering project in its own right. In addition while consulting with industry on this project various other emerging technologies with safety applications to agricultural aviation were examined. Accordingly it was decided to broaden the scope from load measuring technology but limit the depth of the investigation. If necessary a detailed investigation of particular devices could be conducted as a separate project.

In general while various technologies are emerging that will contribute to aviation safety, the gains to be made are small compared to the gains that can be achieved with improvement to the existing machinery and regulation of it. The following chapter discuss three significant technological improvement, hopper load measurement, global positioning system (GPS) tracking and Time in Service Recorders (TSRs), and examines how they might be applied to agricultural aviation.

Hopper Load Measuring Cells The Pacific Aerospace 750XL-AG version was built with a 96 cu ft hopper that incorporates an on-board load-measuring device. This device displays the hopper load on a readout in the cockpit. Although this unit has had some reliability problems, it has proven satisfactory in service. Its functionality is required to enable the aircraft to meet the requirements of DCA/EQUIP/2A22, as the hopper is behind the pilot and not equipped with a translucent window as previous agricultural aircraft have been. This aircraft was designed to be equipped with a load measuring system from the outset due to its configuration. Other attempts to equip existing hoppers with load cells have proved unreliable. An essential problem is that to provide sensitive and accurate load measurement, the hopper should be supported on reasonable flexible mounts, as the deflection of the mounts is being measured to calculate the weight in the hopper. The deflection to be measured occurs at an acceleration of 1 G while the aircraft is being loaded. However the hopper mounting structure has to be capable of withstanding manoeuvre and gust loads factors of at least 3 G, as well as crash loads of up to 12 G when the hopper is mounted behind the pilot. On a new design this engineering paradox can be overcome with difficulty. For existing designs where the hopper mounting is already accommodating existing engineering compromises, fitting a reliable hopper load measurement device becomes even more difficult.

22 Since 1979 Airworthiness Directive DCA/EQUIP/2A has required aircraft on agricultural operations to be provided with a means of indicating to the pilot the quantity of product on board.



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The other option that has been pursued is the measurement of undercarriage deflection, or the resulting increase in air pressure inside the ‘air spring’ that supports the aircraft weight in an oleo-pneumatic piston undercarriage. Deflection measurement devices have suffered from the aggressive (wet, dirty) environment that the undercarriages are subjected to. The air pressure measurement should have proved more reliable but it has some issues to overcome as well. Due to friction in the undercarriage suspension mechanism, and the fact that the aircraft are not always level when they are loaded, the ratio of the air pressure signal to actual hopper contents is variable. An estimated readout from a single undercarriage le pressure sensor is shown in the following graph. A direct readout of this signal in the cockpit would not be useful. However with as sensor on each main undercarriage leg, and some appropriate software to sample and average the signals, it should be possible to obtain an estimate of the load on board. The friction in the undercarriage sometimes prevents an accurate signal being received at rest. As the aircraft starts taxiing the friction is overcome, although uneven ground will produce fluctuations in the air pressure. The software would need to recognise these fluctuation and calculate an average weight as shown by the dotted line on the graph.

Figure 10.1

Although the measurement of on-board load is challenging, pinpoint accuracy is not required. It would be sufficient to measure a 1000 kg load to the nearest 10 kg, which represents a 1% scale error; +/- 20 kg or 2% would probably be acceptable. As one commentator noted in the industry response section, a farmer can get his live cattle weighed with sufficient accuracy for commercial purposes by a mobile weighing device, so the technology exists.

Load Taxi Takeoff

In Flight

cylinder pre-charge

Landing

Unloaded Weight

Oleo Pressure

Time

Loaded weight



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Conclusion 10.1 The engineering challenges presented by on board load measuring are considerable but not insurmountable.

Conclusion 10.2 Onboard load measurement is more feasible if incorporated in the design from conception.

Conclusion 10.3 For existing aircraft designs, the undercarriage oleo pressure method may have potential for further development with appropriate software.

GPS tracking systems In recent years a number of GPS base systems have been developed that provide near real time information about the position of an aircraft, some systems can also estimate speed and height. These systems could provide an increase in safety to crews, particularly when operating in remote areas. The aircraft position signal could be provided to the aircrafts base, or more usefully the loader driver.

Agricultural aviation involves the operation of powerful machinery (up to 750 hp) at speeds of 120-180 kph by a single operator in rough and often isolated terrain. The occupational hazards are obvious. The loader driver is likely to be the nearest person in the event of an emergency. An in-cab display of the aircrafts position would alert the loader driver of any emergency. The loss of signal would be an obvious emergency, but in the recent accident near Opotiki, the sudden divergence of the aircraft from its regular track could alert the loader of an impending emergency situation, as well as pinpointing the crash site. For the information provided by a GPS tracker to be useful, the loader driver would obviously need suitable communication equipment at hand.

Many operators do equip their loader tucks with safety equipment, but the provision of GPS tracking equipment may be desirable for remote area operations. Most of the aircraft accidents happen on take-off or landing, and the loader driver is likely to be the first on the scene, so the vehicle should be fitted with suitable safety equipment. The adequacy of this equipment is best addressed during certification of the operators 137 exposition. The communication requirements would clearly be different for an operator in the Waikato and an operator in the Marlborough hill country.

A GPS tracker would provides some advantages over the existing requirement to fit an automatic emergency locator transmitter (ELT). Recent agricultural accidents have not had a good ELT success record. Often the ELT is damaged in the accident or simply the aerial is broken off preventing transmission of the signal. In the event of a successful ELT activation, it sends a signal on 121.5 kHz (soon to be 406 MHz) which is not always monitored by the loader driver. Although the loader driver will know within about 4 minutes that the aircraft has encountered a problem, due to its non-arrival, it could be some time before the signal is picked up though the rescue co-ordination centre and a location determined.23

23 Up to an hour.



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The inherent engineering problem with ELTs is that they are required to do nothing for most of their service lives. In a brief moment, often while the rest of the aircraft is undergoing structural failure they are required to automatically activate and remain operational throughout the crash sequence. By comparison a GPS tracking device can be provided with normal aircraft power, operates under normal conditions without crash loading, mechanical damage or fire. If any of those do occur, the signal ceases, which provides the alert. Although the signalling technology is more sophisticated, the engineering design challenges are smaller. As such GPS tracking devices offer an enhanced level of safety over ELT and should be recommended for agricultural operations.

The need to provide suitable safety equipment on the loader truck and ensure the loader driver is trained in it’s use was illustrated by the following incident (not recorded on CAA database).

The hydraulic system of the loader truck failed as the full bucket was positioned above an FU2424. Approximately 1000 kg of superphosphate and several hundred kilograms of loader bucket crushed the aircraft fuselage. The pilot was pushed forward onto the cockpit floor. He was trapped there because the rearward-sliding canopy was obstructed by the loader bucket and wrecked fuselage. In his displaced position, he could not reach the crash axe to break the canopy. The loader driver was unable to remove the loaded bucket. Luckily there was no fuel leakage or electrical ignition, before the farmer arrived with a tractor and dragged the loader clear of the wrecked aircraft.

Conclusion 10.4 GPS tracking systems may enhance the safety of agricultural operations in remote areas. To be effective, the loader driver should be trained and equipped to respond to emergency situations. Certification of Part 137 operators is an appropriate means of achieving this.

Time in Service Recorders In the course of the Review, industry stakeholders and CAA staff raised the subject of mandatory TSRs repeatedly. The mandatory provision of a TSR that met the requirements of NZTSO 2001 would doubtlessly improve safety by providing an unalterable record of flight time and takeoff landing cycles. The current TSO does not require recording of the onboard load due to the difficulties discussed above, However the record of flight cycles provides a means of detecting overloading by comparison with the invoices for the amount of fertiliser spread.

No viable device meeting the requirement of the NZTSO has yet been certified. The author of this review has also been involved in the TSR project. In discussion with manufacturers, including some very capable overseas organisations, the inherent problem is commercial viability. Even a simple device will run to approximately a hundred thousand of dollars to develop and certify. As the total market for device in New Zealand, assuming 100% market share is 1000 unit or less, manufacturers have not been in a hurry to develop such a

24 ZK-DMO



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device. The rule requiring the provision of TSRs may be approaching a critical decision point.

Are Time in Service Recorders Necessary? Part 91.509(b)(4) requires aircraft conducting agricultural operations to be fitted with a TSR, although the rule is currently held in abeyance pending development of a device that meets the requirements of NZTSO 2001. Some of the agricultural aircraft in New Zealand have fixed component lives, but there is little concern that these are being regularly exceeded. The requirement of Part 91.509 for time in service recorders for agricultural aircraft was primarily intended to ensure maintenance interval were respected. However they do provide an indirect measure of excessive overloading. A TSR can only do this indirectly, by providing a record of the number of flights completed in a given calendar period, which could be compared with records for the quantity of material dispensed, to get an average load per flight.

The only aircraft types in New Zealand suffering a significant number of occurrences that can be attributed to overloading, such as undercarriage problems, are the FU24 and Cresco series, although between them these two aircraft types together conduct 75% of the agricultural aircraft operations in New Zealand. These aircraft are operating under the provisions of Part 137 Appendix B which extended the privileges of CAM 8 to them without requiring certification to CAM 8 as was required by overseas authorities for the foreign aircraft types, as was discussed in Chapter 3.

As the Cresco undercarriage was certified at the MCTOW of 6450 lbs and 137 permits operation at up to 8256 lbs many of the occurrences may be due to overloading within the provisions of Part 137. Therefore monitoring the operating weight via access to TSR data may keep operators below the Part 137 permitted limit, but still not significantly reduce the occurrence rate. If the operator disregarded Part 137 altogether, the volume of the hopper limits the all up weight of the Cresco loaded with superphosphate to 8554 lbs 25.

By comparison the Flightcare and Turbine Conversions Ltd PT6 powered FU24s with the 66 cu ft hopper fitted have the same hopper volume as the Cresco and can accommodate 4942 lbs of superphosphate. Including the empty weight of the aircraft(3030 lbs), an hour’s fuel (+unusable fuel) and 180 lb pilot, the maximum weight possible with superphosphate is 7992 lbs or 25% more than its Part 137 legal overload weight.

So when considering overloading beyond Part 137 with superphosphate or other common fertiliser blends, the cause for concern is essentially only the FU24 fitted with a 66 cu ft Hoppers. The other significant agricultural types in New Zealand cannot be significantly overloaded with superphosphate. See figure 11.2. With high density material such as lime the other aircraft can be overloaded, but the 66 cu ft version of FU24 does so to a much greater extent than comparative types.

25 For the Cresco, the hopper volume (66 c ft) limits the superphosphate hopper load to 4942 lbs and thus the all up weight to approximately 8554 lbs, which is only 3.6% over the 8256 lb Part 137 limit. (A full hopper of superphosphate exceeds the hopper load limit of 4100 lbs).



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Figure 10.2

Figure 10.2 shows the percentage over or under the Part 137 weight that the aircraft will achieve will a full hopper, 1 hours fuel and crew. This weight has been estimated for the FU24 with 44 and 66 cu ft hoppers, as well as the Cresco (66 cu ft), AT-402B (53 cu ft) and GA 200B (28.25 cu ft). The three sets of data show the full hopper loads with three common products. Lime is the heaviest with a specific gravity of 1.6, urea is the lightest at 0.77 (half the density of lime) and superphosphate is in the middle at about 1.2.26

The standout feature from the figure 11.2 is how much the 66 cu ft FU24 can be overloaded beyond Part 137, in comparison with the other aircraft types. In figure 10.2, note the GA200B and AT-402B can be overloaded with superphosphate by about 10%. Both of these aircraft were designed primarily for spraying aqueous solutions, with densities almost equal to water. The GA200B has a hopper volume of 800 L with a placarded hopper maximum load of 854 kg, which with a pilot and an hour’s fuel takes the all up weight to 3827 lbs or only 0.72% over the maximum weight listed in its type certificate for restricted category operations. Superphosphate has a specific density of 1.15-1.2 so if the hopper is optimised for water based solutions, with the heavier super it will be able to be overloaded by about 15% which is close to what the graph shows. The FU24 with 66 cu ft hopper is optimised for a Part 137 legal load of urea but exceeds the Part 137 overload with anything denser.

In summary, the use of TSRs as a means of detecting overloading is essentially a regulatory tool to prevent gross overloading of the FU24 with 66 cu ft hoppers. If Part 137 had not allowed operation at 31% overload there would have been no justification for fitting 66 cu ft hoppers, even for low volume materials. If the original 44 cu ft hopper of

26 Specific gravity is an expression for a material’s density relative to the density of water. Water has a density of 1000 kg/m3. Superphosphate has a density of about 1200 kg /m3.



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the FU24-950 had been retained, the maximum all up weight with superphosphate would be limited to 6344 lbs, just within the 6366 lb Part 137 limits. With a 44 cu ft hopper the all up weight when full of urea would have been limited to 5164 lbs, which is comparable to the 5430 lbs or 12% MCTOW overload permitted prior to Part 137.

Therefore, when spreading urea, a 44 cu ft hopper could take 2114 lbs, which was about 266 lbs short of the pre-Part 137 capacity, in effect the 44 cu ft hopper was limiting the aircraft to 88% of the pre-Part 137 permitted load of urea. When Part 137 was introduced, the 44 cu ft hopper became apparently only able to take only 43% of the Part 137 load, so it was argued that a bigger hopper was clearly needed, for urea. The hidden fact here is that with 3171lbs of urea in its new 66 cu ft hopper, a piston powered FU24 would have an all up weight of 6221 lbs and struggle to get airborne from most strips with the 400 HP engine. So now the 66 cu ft aircraft had a performance problem even with urea, let alone super. The ‘solution’ was to add a more powerful engine. Of course with a more powerful engine, and the hopper only 75% full with a Part 137 legal super load, the potential to overload with super and other standard fertiliser products became ever present.

Conclusion 10.5 The current problem of loading in excess of Part 137 is partly attributable to the provisions of Part 137 itself, which led to the use of 66 cu ft hoppers. The use of TSRs for fixed wing aircraft may be less urgent if Part 137 were rewritten. The technology to develop a TSR has proved to be more complex and expensive than anticipated, and the outcome of the rewritten Part 137 should be considered before implementing the TSR for agricultural aircraft..27

27 This is not to say the TSR project is without merit. The TSR has very important applications for rotary wing aircraft. The airworthiness of rotary wing aircraft is predicated on flying hours which the TSR measures directly.



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Chapter 11 – Airworthiness Directives Review Scope item three from the terms of reference was to review all the airworthiness directives (ADs) applicable to agricultural aircraft types currently in operation or under certification. The legal basis of ADs, and the policy supporting them is explained below.

Airworthiness Directive Policy The Director issues Ads in accordance with section 72I(3A) Civil Aviation Act 1990, which provides that “where the Director believes on reasonable grounds—

(a) That an unsafe condition exists in any aircraft or aeronautical product; and

(b) That condition is likely to exist or develop in any other aircraft or aeronautical products of the same design,—

the Director may, by notice in writing, issue an airworthiness directive in respect of aircraft or aeronautical products, as the case may be, of that design.”

The CAA controls entry of an aircraft design into the New Zealand civil aviation system by issuing a type certificate (or type acceptance certificate for foreign designs). The type certificate is issued subject to the design meeting certain standards, which are intended to ensure a certain level of performance and/or safety. Continuing airworthiness is the subsequent monitoring function which reviews the service experience of the design. The development of unsafe conditions is evidence that the design for various reasons has not achieved the level of safety that its certification intended. Therefore an AD may require design changes to return the overall design to compliance with the level of safety commensurate with its original certification.

Agricultural Aircraft ADs In the course of the Review the ADs applicable to the Cresco and the FU24 have been examined, particularly those relating to inspection of the vertical fin. During this research it has become apparent that, while the Cresco schedule is reasonably current, the FU24 schedule contains certain redundant and obsolete ADs.

The foreign agricultural aircraft AD schedules are up to date with the state of design ADs, although they will require regular monitoring. This function is undertaken by the Continuing Airworthiness Team.

The Continuing Airworthiness Team has established a group operating project (9AL.AC29) to review the process by which foreign ADs are received and corresponding New Zealand ADs produced. Further work to review the schedule of ADs for agricultural aircraft and, in particular, those for which New Zealand is the state of design will be accomplished under this project. Accordingly the Review did not devote further study to the AD schedules.



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Chapter 12 – Conclusions The Review has reached the following conclusions, which are grouped by the chapter in which they are discussed.

Chapter 1 Chapter 1 outlined the background to the review. There was a perception within the CAA and frequently expressed by leading industry members that the rate of defects and accident was high and increasing. The increasing accident rate was reflected in the CAA’s social cost per flying hour measure for the fixed wing agricultural sector but not in the corresponding rotary wing sector. Accordingly the Agricultural Aircraft Safety Review was launched to quantify these concerns.

Chapter 2 – The Lewis Report The Lewis report was a review of the overload provisions of Part 137 carried out by an experienced independent industry consultant. The Lewis report had made a number of recommendations to improve the safety of operations conducted under Part137. Chapter 2 reviewed the recommendations of the Lewis Report and came to the following conclusions.

Conclusion 2.1 The Lewis Report provides a detailed assessment of certain issues faced by agricultural aircraft operating under Part 137. The opinions expressed in the Lewis Report are plausible and the aerodynamics calculations are correct.

Conclusion 2.2 The Review supports the principal conclusion of the Lewis Report that Part 137 does not provide an adequate basis for operations beyond MCTOW.

Conclusion 2.3 The Lewis Report’s recommendations (1-4) on the CAA providing further guidance material to detail an aircraft’s performance at the agricultural weight may improve safety but would not address the increasing equipment failure rate that is likely to be experienced when the aircraft is operated outside of its design envelope. The provision of further guidance material from CAM 8 is unlikely to be useful, firstly, because CAM 8 was not intended to be an operational rule, and, secondly, the FU24 and Cresco were not certified to CAM 8. .

Conclusion 2.4 The Review supports recommendations 5 and 6 of the Lewis Report regarding loading bucket weight devices and mandatory TSRs.

Conclusion 2.5 The Review conditionally supports recommendation 7 of the Lewis Report regarding fatigue assessments of aircraft refitted with turbine engines. (FAA AC 23-14 supports the re-assessment of horizontal stabiliser fatigue.)



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Turbine conversions represent a considerable investment in an old airframe, and operators expect such conversions to substantially extend the economic life of an aircraft. As such, re-engined aircraft are, in effect, a changed product. New Zealand currently has no clear ‘changed product rule’, but the need for one has been noted.

Conclusion 2.6 The Review supports recommendation 8 of the Lewis Report regarding engineering assessment of the undercarriage. The undercarriage should be assessed as part of a co-ordinated certification process at the nominated agricultural weight. To complete the engineering assessment of the undercarriage, a CAA policy on acceptable agricultural weight should be determined.

Conclusion 2.7 Recommendation 9 of the Lewis Report regarding publication of strip guidelines has been adopted with effect from December 2006.

Conclusion 2.8 Operation at weights beyond an aircraft’s original MCTOW is feasible when an engineering analysis establishes that sufficient capability exists in the affected structural components, and satisfactory flight characteristics are demonstrated. If operations at high weights for agricultural purposes are to continue, there is a requirement for:

a) A suitable certification basis for the engineering assessments that takes into account the nature of agricultural operations, b) A suitable set of operational parameters including, but not limited to, climb gradient, take-off performance, and stalling speed.

Chapter 3 - Regulatory Basis of Part 137 and CAM 8 Chapter 3 follows on from the Lewis reports critique of Part 137 and makes a detailed review of the regulatory basis for Part 137 and compares it with the United States Civil Aviation Manual No 8 on which it is based. Chapter 3 concludes that there are anomalies and discrepancies in Part 137 that should be corrected as follows.

Conclusion 3.1 The overload provision of Part 137 do not provide an adequate basis for operations at weights beyond MCTOW.

Conclusion 3.2 The overload provisions of Part 137 do not adequately specify how a restricted category (agricultural) weight for a given aircraft type can be safely established.

Conclusion 3.3 The best way to establish a technically and operationally safe restricted category weight for the purposes of agricultural would be the establishment of a working grop consisting of industry representatives and operations GA operations staff, supported by ACU engineering staff.



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Conclusion 3.4 There is a need to fully review current FAA practice for agricultural operations and current FAA certification requirements for new agricultural aircraft when developing the acceptable means. However, United States’ requirements should not necessarily be adopted without modification as New Zealand agricultural operations have unique and well-recognised characteristics that should be taken into account.

Conclusion 3.5 CAD leaflet C.10-1 to C.10-4 could be considered as a basis for establishing an acceptable means of operation beyond MCTOW.

Chapter 4 Section 1 - CAA Safety Data Review To determine if the deficiencies within part 137 or other factors were manifestly affecting the safety of agricultural operations, a detailed review of the CAA’s safety occurrence data was undertaken. The First section describes how a new method of doing this was developed, and in the process makes the following recommendations.

Conclusion 4.1 The current CAA safety information management system does not permit easy analysis of certain safety data. The techniques used in the Review could be adapted to provide the CAA with enhanced research capabilities.

Conclusion 4.2 This comparison verifies the validity of the occurrence categorisation method as a way of comparing the relative performance of different aircraft designs in service. The distribution of occurrences is a function of both the soundness of the design and its operating environment. Together they represent the design’s fitness for purpose or airworthiness.

Chapter 4 Section 2 - Data Analysis Conclusions: The second section of Chapter 4 details the results of the occurrence data review and notes in several key areas the safety of agricultural operations had become worse in recent years. In particular the occurrence rate increased after the overload rule was introduced in 1994. The key conclusion were as follows:

Conclusion 4.3 The FU24 has experienced a high rate of undercarriage failures, compared to the three most popular foreign agricultural aircraft types. The FU24 failure rate between 1994 and 2007 is 136% of the foreign agricultural aircraft undercarriage defect rate.

Conclusion 4.4 The rate of FU24 undercarriage failures has increased markedly since 1994 when Part 137 introduced the permissible overload graph in Appendix B.

Conclusion 4.5 The rate of FU24 undercarriage failures increased even more dramatically in 2001 when approximately 50% of the fleet was converted to turbine engines. This is most likely



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because the 38% increase in take-off power allowed the overload provisions to be more fully and more frequently exploited. This led to higher average loads on the undercarriage and more frequent exposure to very high loads.

Conclusion 4.6 The Cresco suffers a high rate of undercarriage failures. Since the PT6-34 powered Crescos entered service after 1994, sufficient data is not available to gauge the rate of failure before the introduction of Part 137 Appendix B. Since entering service the Cresco has suffered 0.515 failures per 1000 flying hours. This rate is 3.4 times higher than the FU24 rate and 4.5 times higher than the foreign agricultural aircraft undercarriage defect rate.

Conclusion 4.7 The three foreign agricultural aircraft types, when analysed in the same way, do not show significant increases in undercarriage failures in either 1994 or 2001. This rules out external factors as a cause of the increase in failures.

A small increase in performance related accidents occurred after 1994. This may have been due to operators exploiting or even exceeding the provisions of Part 137, although the hopper capacities of the foreign agricultural aircraft have limited the degree of overload with superphosphate to approximately 10%.

Chapter 4 Section 3 - Aircraft Comparisons During the review of the occurrence data it was necessary to compare aircraft chrarchteristics. This Chapter lists these chrarchteristics for easy reference and uses them to make some comparisons.

Conclusion 4.8 PAC aircraft have a low structural weight in comparison to their MCTOW. While this is not inherently unsafe, it highlights the need for the structure to be maintained to a high standard.

Chapter 5 - Unreported Incidents

Conclusion 5.0 Industry actively reports incidents of defects to the CAA. There is no evidence to suggest that overall reporting rates have declined significantly.

Chapter 6 - Turbine Conversions This chapter examined the wide ranging concerns regarding the various turbine engine conversions of the FU24 aircraft. The turbine powered aircraft have suffered a higher than expected defect and accident rate since their widespread introduction around 2000. The reason for this are complex and include technical, regulatory and operational issues. In the case of the turbine powered FU24, these factors have combined to produce a marked deterioration in the aircrafts safety and reliability.



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Conclusion 6.1 Since their introduction, the turbine-powered variants of the FU24 have suffered a slightly higher accident rate than the piston-powered variants.

Conclusion 6.2 The defect rate per flying hour of the turbine aircraft has remained higher than the defect rate for piston engine aircraft since their introduction.

Conclusion 6.3 STC approval procedures should include a review of the service history of the airframes to which new engines are fitted for issues that may be exacerbated or revived by the STC.

Conclusion 6.4 CAR 21.119 should be reviewed to determine whether the Director may impose additional conditions on the applicant for an STC if a review of the airframe type’s service history indicates additional conditions would be appropriate.

Conclusion 6.5 Consideration should be given to the introduction of a ‘changed product’ rule to clarify the conditions to be imposed on modifications that essentially change the nature of an existing product, such as the change of motive power or restarting production.

Conclusion 6.6 CAA policy relating to Part 21 subpart E regarding the Director’s power to specify the special conditions or later certification basis for extensive STC modifications is not clearly defined. As a result CAA policies regarding amendments to type certificate and approval of STCs may have been inconsistently applied.

Conclusion 6.7 The introduction of Part 137 in 1994 extended privileges to the FU24 (and Cresco) that could not be substantiated. The impact of these privileges was obscured until the more powerful turbine engines were fitted in 2001. In this sense Part 137 undermined the assumptions used to approve the turbine conversion.

Conclusion 6.8 The combined effect of the Part 137 weight increase and the turbine conversions was a sharp increase in aircraft defect rates, particularly evident in the rate of undercarriage failures.

Conclusion 6.9 A further unintended effect of the turbine conversions may have been to halt the introduction of newer aircraft, such as the Cresco, GA200 and possibly the AirTractor.



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Chapter 7 - Certificate of Airworthiness Duration

Conclusion 7.1 Although favoured by many industry stakeholders, the reintroduction of terminating COAs is unlikely to raise maintenance standards. It would also increase costs for industry and the burden on the CAA.

Conclusion 7.2 A better means of raising the standard of airworthiness for agricultural aircraft is to recognise them as special purpose machines and require specific maintenance programs.

Conclusion 7.3 Expertise in agricultural aircraft lies with industry, and a comparison of leading industry maintenance programs could lead to the production of a ‘best industry practice’ maintenance program. This would share expertise across the industry and raise overall safety. Such a program, along with relevant ADs and SBs, should be fed back to the OEM, and incorporated into the OEM maintenance program. This would become the reference standard for operator programs approved under 91.607. (This would still allow variation from the OEM program, but with explanations.)

Conclusion 7.4 There is a need to review the approval of maintenance programs for agricultural aircraft. Because of the demanding operations, and their predominance in the New Zealand agricultural industry, priority should be given to the New Zealand type designs.

Chapter 8 - Re-use of Data Plates

Conclusion 8.1 Returning the data plate to the CAA is unlikely to be a practical way of controlling the airworthiness of aircraft rebuilt from wrecks. Revoking the COA for aircraft that are ‘written off’ may be a more effective means.

Conclusion 8.2 The CAA’s ACU, Legal, and GA groups need to consider the legal aspects of revoking the COA for aircraft that are ‘written off’, and liaise with insurance industry.

Chapter 9 – Industry Operational Issues Significant numbers of industry members, including some of the most experienced members, have expressed strong concerns about aspects of agricultural aircraft safety. Conclusion 9.1 The current rule regarding operation beyond MCTOW is not well regarded by aircraft crews Conclusion 9.2 Airworthiness of the FU24 aircraft is a commonly expressed concern.



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Chapter 10 – Emerging Technologies

Conclusion 10.1 The engineering challenges presented by on board load measuring are considerable but not insurmountable.

Conclusion 10.2 Onboard load measurement is more feasible if incorporated in the design from conception.

Conclusion 10.3 For existing aircraft designs, the undercarriage oleo pressure method may have potential for further development with appropriate software.

Conclusion 10.4 GPS tracking systems may enhance the safety of agricultural operations in remote areas. A solution may be to train and equip loader drivers to respond to emergency situations. Certification of Part 137 operators is an appropriate means of achieving this.

Conclusion 10.5 The current problem of loading in excess of Part 137 is partly attributable to the provisions of Part 137 itself, which led to the use of 66 cu ft hoppers. The use of TSRs for fixed wing aircraft may be less urgent if Part 137 were rewritten. The technology to develop a TSR has proved to be more complex and expensive than anticipated, and the outcome of the rewritten Part 137 should be considered before implementing the TSR for agricultural aircraft.

Chapter 11 No relevant conclusions were made in relation to Chapter 11 – Airworthiness Directives Review.

.



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Glossary of Legal and Institutional Acronyms

AAA New Zealand Agricultural Aircraft Association

AC Advisory Circular issued by the CAA to provide explanatory information and examples of how to comply with a Civil Aviation Rule

ACU Aircraft Certification Unit of the CAA

AD Airworthiness Directive issued by the Director of the CAA in accordance with section 72I(3(a) Civil Aviation Act 1990

ARA Annual review of airworthiness. In effect an audit of the aircraft and it’s records to ensure the required maintence has been accomplished.

ARC Aviation related concern

ATA Airline Transport Association

CAA Civil Aviation Authority of New Zealand. A Crown entity established in accordance with section 72A Civil Aviation Act 1990. Among other functions, the CAA establishes civil aviation safety and security standards, and monitors adherence to those standards

CAD Civil Aviation Department, forerunner of the CAA

CAM Civil Aeronautics Manual, maintained by the FAA



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CAR Civil Aviation Rule issued by the Minister responsible for the administration of the Civil Aviation Act 1990 in accordance with section 28 of that Act

COA (or C of A)

Certificate of Airworthiness, now termed Airworthiness Certificate.

FAA The United States’ Federal Aviation Administration

FAR Federal Aviation Regulation issued by the FAA

GA General aviation (see, for example, the GA Group of the CAA)

IA Inspection Authorisation. CAA endorsement of an Aircraft Engineers Licence to carry out certain functions.

NZTSO New Zealand Technical Standard Order; contains information about the minimum performance standard for equipment that the CAA considers acceptable to comply with an applicable rule

OEM Original equipment manufacturer

SAU Safety Analysis Unit of the CAA

SB Service bulletin. Service information issued by a manufacturer.

STC Supplemental type certificate

TSO Technical Standard Order – FAA performance standard for aeronautical equipment

USCAA The United States’ Civil Aeronautics Authority; forerunner of the FAA



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Glossary of Scientific Terms

cg

Centre of gravity

cu ft Cubic foot. 1 Cu ft =28.31 litres,

G

Measure of acceleration as it effects items of mass. 1 G generates a force equivalent to that experienced by an item of mass at rest in the earth’s gravitational field at sea level. (9.814m/s2)

ELT

Emergency locator transmitter

GPS

Global positioning system

hp Horse power

knot

Nautical mile per hour

MCTOW

Maximum certified take-off weight

Payload

Useful load carrying ability of the aircraft. Equal to the MCTOW minus the aircraft empty weight , crew , fuel & lubricant.

PLTOW Performance limited take-off weight

ROC

Rate of climb

SG Specific gravity. The ratio of the mass of a given volume of a substance to the mass of the same volume of water. Substances with SG > 1.0 will sink in water.



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Vs Stalling speed. Minimum speed at which the aircraft can generate enough lift to supports its weight.

Va Velocity maximum acceleration. This is the speed at which the aircraft is capable of reaching its manoeuvre G load limitations. At speeds below Va full control deflections are possible without exceeding the aircrafts manoeuvre limitations At speeds above Va care must be taken not to overstress the aircraft during manoeuvres.

Vno Velocity normal operations, the maximum speed recommended for normal operations.

Vne Velocity Never Exceed – The maximum permissible speed.



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Annexes:

A Terms of Reference for Agricultural Aircraft Safety Review

B Civil Aeronautics Manual (CAM) 8

C New Zealand Civil airworthiness Requirements – Part 2

D Air Transport Division – Ministry of Transport – Engineering Instruction

E FU24 Occurrences

F Cresco Occurrences

G 750XL Occurrences

H GA200 Occurrences

I Air Tractor Occurrences

J Cessna Agwagon Occurrences

K Transavia PL-12 Airtruk Occurrences

L Zlin Z-13T Occurrences

M FU24 Fin Failures and Occurrences – Summary

N FU24 Fin Structural Comparisons

O Climb Performance

P Landing Gear Considerations


Terms of Reference for Agricultural Aircraft Safety Review


27 January 2007 Page i

Table of Contents

Terms of Reference for Agricultural Aircraft Safety Review Background ...................................................................................................................... 1 Purpose ............................................................................................................................ 1 Authority ........................................................................................................................... 1 Scope .............................................................................................................................. 1 Review Process ................................................................................................................ 2 Time Frame ...................................................................................................................... 3


27 January 2007 Page 1

Terms of Reference for Agricultural Aircraft Safety Review Background There is increasing concern in GA Group operational staff and sectors of the agricultural aviation industry regarding the rebuilding of aging aircraft and, in particular, the use of old airframes with new components and significantly more powerful engines.

The aircraft being re-engined are generally very old. In some cases, the wings and sections of the fuselage have been re-skinned but the structure remains basically the same. The aircraft have given many years of service in rugged conditions. As well as lengthening the fuselage to keep the centre of gravity (CG) within limits because of lighter engines, fuselage plugs are added to accommodate larger hoppers. Little else is new. Such aircraft are stated to have a rejuvenated life, as if new. In addition to carrying significantly heavier loads, the powerful new engines are capable of driving the aircraft to much higher speeds.

Associated with the concerns are reports (many of them anecdotal) of the rate of defects/ failures occurring in areas such as the undercarriage, tail fin/rudder structure, wing spar and engine mounts.

Of added concern is the relative lack of appreciation of aerodynamics, weight and balance by many agricultural pilots, in particular the need to reduce speeds, manoeuvre and G loadings at high all up weights.

The matter of deregistration of crashed aircraft and the re-use of data plates is also included in these concerns.

Purpose The purpose of the investigation is to gather information, authenticate anecdotal stories as far as is possible and make recommendations regarding currently operated agricultural aircraft design, continuing airworthiness, maintenance and operational practices and techniques.

Authority This review is sponsored by General Manager General Aviation (GMGA) John Lanham.

The Terms of Reference for the review have been written by Manager Rotary Wing and Agricultural Operations (MRW/A) Unit John Fogden.

Scope The scope of the review is to:

• Review the Bernie Lewis report commissioned and completed in 2005 and to review the resultant recommendations.

• Review all New Zealand Civil Aviation Authority documented safety occurrences, findings and open actions relating to agricultural aircraft.



• Review NZ airworthiness schedules for all agricultural aircraft types currently in operation or under certification.

• To conduct a study in association with NZ agricultural aviation operators and pilots to further quantify possible unreported incidents, occurrences, defects and structural failures and structural fatigue.

• Consider the airworthiness and operational implications of operating modified agricultural aircraft where old airframes are being fitted with more powerful turbine engines.

• Consider the implications of current non-terminating certificates of airworthiness in the agricultural context (i.e., vs four yearly and eight yearly rebuilds).

• Review NZCAA policy for the re-use of data plates from crashed aircraft.

• Discuss with industry broader operational safety concerns such as hopper size, compliance with Limitations, Appendix B Overload provision.

• Consider the available technology to assist the measuring, recording and retrieval of hopper loads.

Review Process The review team will be comprised of representatives from the CAA Aircraft Certification, Safety Investigation, Safety Analysis and Rotary Wing/Agricultural units. The team consisting of Jack Stanton, Bob Jelley, Ivan Harris and representatives from Safety Analysis (Peter Nalder) and Safety Investigation (Ian Stobba) with Elizabeth to assist as SAO is to conduct an investigation in accordance with these Terms and report to the GMGA.

The team is to:

• Conduct its reviews of documented occurrence, defect and accident reports, airworthiness schedules and the Bernie Lewis report, using internal CAA database material.

• Conduct its investigation of undocumented information, anecdotal evidence and opinion from reputable and appropriately experienced agricultural aviation sources.

• The investigation is to be conducted in a manner that supports a combination of document reviews, interviews of persons as appropriate and receiving of written submissions and responses as the team considers necessary.

The following steps must be followed by the Review team:

1. Identify and confirm with MRW/A:

• that the Review team understands the proposed format and procedure of the review;

• that reputable and appropriately experienced aviation sources are identified and agreed on, for the purpose of industry consultation; and

• establish if there are potential conflicts of interest or difficulties regarding the disclosure of the identity of any potential industry contributors.

2. Plan and pre-book (with SAO) regular meeting dates within the specified timeframe.



3. Review and analyse existing documentation and information, establish any other documentation required, obtain that information, then review and analyse it.

4. Establish a method and program of liaising with industry contributors that will be most cost and resource effective . Alternatively, the team may draft questionnaires for witnesses to respond to.

5. Assess evidence collected and compile a draft report.

6. Consider and recommend to GMGA whether a draft report should be made available to industry contributors or the agricultural industry at large.

NOTE: It can be anticipated that the Agricultural Industry Association (AAA) will wish to be closely consulted. It is important to the integrity of the review that consultation is not limited solely to senior AAA members and that a representative cross-section of the industry is considered during the review, particularly including employed pilots, their loader drivers and aircraft maintainers.

After considering the final report, the GMGA shall make recommendations to the Director. The Director will consider the final report and the recommendations and make any appropriate decisions regarding ongoing agricultural aircraft design, continuing airworthiness, maintenance and operational practices and techniques.

Time Frame This investigation should be completed as soon as the existing routine workload of the review team members allows. Preference should be given to this project when near to mid-term work programmes are being established.

MRW/A and GMGA shall be fully appraised of the progress of the investigation and shall be informed if any amendment is required to the specified time frame.

John Fogden Manager RW/A General Aviation Group 25 January 2007

Annex B to Agricultural Aircraft Safety Review

CAM 8 Synopsis Page 1

CIVIL AERONAUTICS MANUAL 8 (CAM 8) A Brief Synopsis

Introduction CAM 8 was the policies and interpretations of the Administrator of Civil Aeronautics to Part 8 of the regulations of the Civil Aeronautics Board, and became effective on October 11, 1950. At that time Part 8 was new, and a significant departure from previous restricted category airworthiness requirements. Part 8 was the regulation governing the issue of type certificates and airworthiness certificates in the restricted category.

This new Part 8 departed from the previous requirements that were requiring an equivalent level of safety as a passenger-carrying aircraft. The Administrator accepted that for special purposes, in this case agricultural, compliance with restricted category requirements was simplified, and the operating limitations would be tailored to the purpose of the operation. Although that simplification eased the requirement to provide engineering data and so on, there was still a requirement that good engineering practice was maintained, and that no feature of the design or modification would render the aircraft unsafe. The idea behind Part 8 was to provide the greatest flexibility and minimum burden on the operator consistent with public safety.

Part 8 Applicability Established standards for the issuance of type and airworthiness certificates for aircraft in the restricted category. It also established operating limitations applicable to such aircraft.

Eligibility for type certificate Addressed aircraft that were type certificated in another category, military aircraft, and modifications. Required conformance to good aeronautical practice and that no feature or characteristic of the aircraft rendered it unsafe when operated in accordance with the limitations prescribed for its intended use.

8.10(a)(1) addressed aircraft that had not been type certified in another category, and referred to Appendix B to CAM 8 as guidance for showing compliance with the applicable airworthiness requirements (eg CAR 3).

8.10-3 dealt with aircraft modified from a previously approved type. It contained requirements such as who could perform the modification, flight checking, hazards to avoid, and approval of the modification which included the Administrator’s agent or designee prescribing operating limitations.

8.10-4 dealt with agricultural aircraft modifications (to aircraft previously type certified in another category) and applied to aircraft where operations were normally conducted over open areas. It referred to the guidance contained in Appendix A to CAM 8.

8.20 dealt with the issue of airworthiness certificates where the aircraft has been type certified or modified per section 8.10, inspected by the Administrator, and the Administrator has prescribed operating limitations. This section was administrative and covered aircraft inspection, airworthiness directives, aircraft marking, repairs and alterations and their data, maintenance and maintenance facilities, and approval of major repairs and alterations.



8.30 dealt with operating limitations that the Administrator must prescribe, in addition to those required in this section, as he finds necessary for safe operation and protection of the public.

8.30-1 required that the special purpose operations and operating limitations would be listed, along with the limitations in sections 8.31 through 8.34.

For agricultural operations, examples of operating limitations were –

1. The aircraft shall not be operatied in any manner which will endanger public life and property. The operator shall adjust the take-off weight to provide a safe margin of performance for the existing operating conditions, considering the take-off area, altitude, temperature, and terrain. For maximum capacities of hoppers and spray tanks see placards.

2. Maneuvers shall be limited to those normally performed in agricultural operations.

3. Agricultural and pest control operations shall not be conducted over densely populated areas, in congested air lanes, or in the vicinity of busy airports where passenger transport operations are being conducted, unless the Administrator finds it in the public interest to authorise such operation and has issued a Certificate of Waiver or Authorisation.

4. Persons and cargo shall not be carried for compensation or hire.

5. Persons other than the minimum crew necessary for the agricultural operations shall not be carried during these operations.

6. No person shall be carried in the aircraft unless a seat and safety belt, installed in accordance with good aeronautical practice is provided for his use.

Examples of additional limitations were –

1. A prohibition against sulphur dusting, unless special fire previention measures have been incorporated in the aircraft.

2. A statement in the area operating limitations that the aircaraft is not eligible for a waiver to operate over congested area because of uncertificated poerplant components.

3. Restricted engine speed (rpm) ranges, if a metal propeller stress survey indicates the need for such a restriction.

8.31 dealt with area operating limitations. This was regarding waivers to operate in congested areas, and was largely administrative.

8.32 dealt with economic operating limitations. This was regarding the ability to carry another person in transit (loader driver) and associated equipment without it being regarded as being for hire or compensation.

8.33 prohibited the carriage of passengers during special purpose operations.

8.34 dealt with separate operating limitations for multiple airworthiness certification, converting from one category to the other, the instructions, and the owner’s responsibility.

Appendix A – Restricted Category Aircraft Modifications 1 – Structural Changes Stated that is a practical guide in the structural considerations when modifying an aircraft for agricultural use. This section discussed the effects of alterations from structural and



aerodynamic perspectives, conversion of personal aircraft types to agricultural use, general rules for proper alteration of the aircraft structure, attachment of hopper or tank to primary structure, boom installations, and corrosion protection.

2 – Dispensing Equipment Design Criteria This section dealt with sources of information regarding equipment design, hopper materials, seams, doors, volume calculations, agitators, spray tank design, venting, baffles, spray booms, nozzles, cockpit draining, etc.

3 – Powerplant Changes This section dealt primarily the structural issues regarding the installation of a different engine type such as engine mounts with the associated change in weight.

4 – Pilot Safety Items This section dealt with the issues such as visibility, location of instruments, seat belts and harnesses, ventilation, and crash protection.

5 – Electrical Systems This section dealt with possible changes to the electrics and addressed generators, environmental conditions, cable selection, terminals, lights, switches. It also covered the installation regarding cable runs, bonding, etc.

6 – Fire Protection This section dealt with the fire hazards that could be encountered from the materials being dispensed such as sulphur. Areas covered were exhaust sparks, static electricity, and spraying of combustible liquid.

7 – Weight and Balance 7.0 General This section stressed the importance of weight to the structure, of weight control and balance, and that if approved limits are exceeded then flight tests should be made

7.1 General Effects of Gross Weight Changes This section begins a discussion on the relationship between the design load factor and gross weight. It made the point that gross weights chosen should permit safe operation under all normal and emergency conditions. The chart that is currently reproduced in CAR Part 137 Appendix B is mentioned as a guide to determining gross weight provided the aircraft is flown in a restricted manner.

7.10 Effects of Gross Weight Changes on Aircraft Structure This section noted that the aircraft landing gear and supporting structure are particularly critical if the aircraft is landed overweight; and taxiing is very likely to be unfavourably affected by increased gross weights. With the increase in gross weight there must be a proportionate decrease in the load factor that can be reached in flight. It again notes that caution should be exercised in all flights at overload weights whether or not they are below the possible maximum. There was some discussion on the distribution of load with respect to the structural strain on the fuselage

7.11 Effects of Gross Weight Changes on Maneuvers This section notes that to prevent excessive loading the aircraft must be maneuvered cautiously, and that the stalling speeds are increased and stalls in turns are more easily encountered. A lower allowable load factor means restricting bank angle. Another factor is gust loads; the level flight and never exceed speeds should be reduced by the ratio of specification weight to overload weight but not below maneuvering speed. Again it advised caution in all flight conditions. There was discussion about pull-up speeds and the use of full deflection of control surfaces.



7.2 Weight and Balance Computations This provided guidance on aircraft weighing.

7.3 Effect of c. g. Position on Structural Strength This section discussed the effect of increased gross weight operation on structural strength, and in particular around the landing gear.

8 – Powerplant Installation The manual provided considerable guidance on design factors for the powerplant installation including the engine, cowling, firewall, propeller, fuel and oil systems, cooling system, induction and exhaust system. In addition the supply and control systems aft of the firewall, and instrumentation, are covered. This section was directed at the airworthiness evaluation of the powerplant installation, and ensuring satisfactory powerplant operation was achieved under the atmospheric conditions, altitudes, and maneuvers to be encountered.

It advised the use of type certified engines and propellers. It also covered engine/prop vibration characteristics with respect to blade stress, and some performance aspects associated with differing propellers.

9 – Flight Test This section addressed flight testing and began by stating that “There are certain principles in the field of aeronautical engineering wheich do not enter directly ino piloting but which are well for a pilot or an operator engaged in agricultural operations to understand in order to know what claims may reasonably be made for an airplane of known weight and power. These principles relate to performance which includes climb, distances required to take-off and land, etc.”

It made the point that aircraft used for agricultural operations have sufficient climb performance to avoid obstacles, and minimise stall/spin possibilities. The manual then went on to discuss the factors affecting climb performance, and used examples from aircraft of the time (Aeronca 7AC, Boeing 75, Navy N3N, Piper PA11, etc), and included a rate-of-climb correction chart for temperature and pressure.

Appendix B – Airworthiness Criteria for Agricultural and Similar Special Purpose Aircraft .0 – Basis and Purpose These criteria were derived from CAR 3 and apply to single engine aircraft intended for low speed dusting or spraying or similar. Following subsections described the procedure for showing compliance, inspections and tests, changes, definitions, etc.

.1 – Flight Flight tests should be made to demonstrate the existence of satisfactory flight and ground handling characteristics.

Weight and centre of gravity ranges should be established. Maximum weight should not exceed the weight selected by the applicant, the design weight for the structure, or the maximum weight at which compliance with the flight standards is demonstrated.

Performance was dealt with for – stalling speed (stalling speed limit at maximum weight 70 mph; recommended less than 55 mph at max weight), and normal climb (at least 8 times stalling speed or 300 feet per minute which ever is the greater, at max weight).



Flight characteristics was dealt with regarding controllability in a variety of conditions. Topics covered were longitudinal control, trim, stability, static longitudinal stability in climb, static directional and lateral stability, dynamic stability, stalling (level and turning flight)

Ground characteristics dealt with longitudinal and directional stability as well as shock absorption and flutter/vibration.

.2 – Strength Criteria This section contained an extensive list of load criteria (both limit loads and ultimate loads), safety factor, flight loads, design airspeeds, flight load factors, wing loadings under varying conditions, landing loads, structural criteria such as fuselage to wing attach points, dead weight items, control system design conditions, engine mount loads, landing loads, landing weight, landing gear loads and drop tests.

.3 – Design and Construction Standards This section contained criteria applicable to various design tasks such as control systems, crew protection, cockpit hazards, cargo provisions, toxic materials, corrosion protection, dispensing installations, and aircraft structure covering.

.4 – Powerplant Installation This section dealt with powerplant and propeller installation standards, and associated components and systems, such as fuel and oil tanks, and powerplant controls.

.5 – Equipment This section listed the required and recommended instruments and equipment.

.6 – Design and Operating Limitations and Information Design limitations were established and submitted to the (then) CAA for inclusion in the aircraft specification. They were airspeeds (Vne, Vm, Vfe), powerplant (rpm, manifold pressure, octane rating), maximum weight, and centre of gravity.

This section also covered markings and placards.

.7 – Identification Data Required an ID plate to be attached to the aircraft.

Annex C to Agricultural Aircraft Safety Review

C1


C2


C3


C4


C5

Annex D to Agricultural Aircraft Safety Review

1


2


3

OCC No Code Sev Date Time UTC

Reg Location Description Part Defective

P/N Part S/N TAIC Reference

Class Total

91/812 DEF MA 1/01/1901 EGX WHANGAREI

0 1

89/36 ACC MA 6/04/1989 CTO NR MOA CREEK

Still under investigation 89-039 0 2

91/118 DEF MA 1/03/1991 EMB NAPIER 0 3

91/119 DEF MA 15/03/1991 CBG NAPIER 0 4

91/122 DEF MA 24/03/1991 EMB NAPIER 0 5

91/150 DEF MA 11/04/1991 EMV BLENHEIM 0 6

91/399 DEF MA 12/08/1991 DZM MARSTERTON

0 7

91/440 DEF MA 25/08/1991 CBG NAPIER 0 8

91/809 DEF MA 5/09/1991 EMV GISBORNE 0 9

91/905 DEF MA 30/09/1991 EMU PALMERSTON NORTH

0 10

91/894 DEF MA 30/10/1991 CMN WHANGAREI

0 11

91/906 DEF MA 30/10/1991 CMN PALMERSTON NORTH

0 12

91/1218B DEF MA 29/12/1991 BOF KAWERAU 0 13

92/174 DEF MA 4/02/1992 CRY WHANGAREI

0 14

92/1074 DEF MA 27/03/1992 DLQ NOT STATED

0 15

92/1107 DEF MA 14/04/1992 EGI MOSGIEL 0 16

92/1751 DEF MA 15/05/1992 CRF UNKNOWN 0 17

92/1671 DEF MA 5/06/1992 CBG NAPIER 0 18

92/2207 DEF MA 27/06/1992 DMV UNKNOWN 0 19

92/2434 DEF MA 10/08/1992 EUG UNKNOWN 0 20

92/4531 DEF MA 29/11/1992 CMK WANGANUI

0 21

Annex L: FU 24 Occurrences 1

93/259 DEF MA 11/01/1993 DLQ HAMILTON 0 22

93/350B DEF MA 28/01/1993 DZF 10NM DANNEVIRKE

0 23

93/901 DEF MA 29/01/1993 EGK WANGANUI

0 24

93/793 DEF MA 11/02/1993 EMO PALMERSTON NORTH

0 25

93/1507 DEF MA 22/02/1993 CQB MOSGIEL 0 26

93/1548 DEF MA 18/03/1993 CMZ HAMILTON HUB CT86 0 27

94/83 ACC MA 13/01/1994 CMK Otupae Stn, 20 NE Ta

tba 0 28

94/554 DEF MI 3/02/1994 DZO HAMILTON 51108 0 28

94/2122A DEF MI 10/05/1994 EMX HAMILTON 0 29

94/4694 ACC CR 22/12/1994 BII N Waimate 0 30

02/2253 INC MI 24/07/2002 DJE Hamilton Immediately after becoming airborne the pilot of the Fletcher reported that he was making a precautionary landing. He landed safely in the lucerne beyond the grass runway and taxied back to the maintenance hangar.

0 31

05/3734 INC MA 19/11/2005 DZC Riwaka RCCNZ reported that Nelson Tower received a Mayday call from ZK-DZC. The aircraft was making a forced landing at Riwaka. The pilot later radioed the tower and advised that he had landed safely and did not require assistance

0 32


07/4039 ACC CR 10/11/2007 EGV Opotiki The aircraft went overdue on a crop dusting sortie and was later found to have collided with some trees and crashed into a gully. The pilot was killed.

0 33

08/2505 DEF MI 5/06/2008 EMW Hamilton SuperAir Ltd reported that on an unscheduled maintenance phase found bracket 243665R (modified to TEL-02-008-4) cracked lower beside weld.

Lower R/H Bracket

0 34

72/78 ACC MA 22/08/1972 BIH REREWHAKAAITU

During a sowing run the fin of the aircraft collided with a 12-gauge steel wire suspended 150 ft above a gully and carrying power to an electric fence in an adjoining paddock. the aircraft remained controllable and was flown back to the strip.

72-085 1 1

73/70 ACC MA 8/05/1973 CMK MARYBANK In flight separation of the fin and rudder occurred during a ferry flight to base. severe corrosion had weakened the vertical spar to an extent that it failed during a lefthand turn. the aircraft then entered a lefthand spiral dive but recovery was made with sufficient height to enable an emergency landing to be made.

73-067 1 35


75/123 ACC MA 17/11/1975 CZA TAHORA At end of sowing run pilot initiated a climb to make another run but found elevator jammed in forward position. forced landing made. aircraft touched down heavily on a small flat area on otherwise rugged terrain. investigation revealed that forward attachment of fin had failed due to progressive corrosion. fin and rudder had then folded backwards across the tailplane.

75-119 1 36

76/125 ACC MA 4/11/1976 BSM PIRONGIA Failure of the forward fin attachment fitting due to severe corrosion caused the fin and rudder to separate in flight. control difficulties resulting in the aircraft being forced to land on inhospitable terrain and slide over a bank

76-121 1 37

82/34 ACC MA 30/03/1982 EGH MAUNGAKARAMEA

The fin forward attachment fitting failed in normal cruising flight. the pilot executed an emergency landing without further incident. a fatigue fracture had initiated from the heavily corroded surface of the fin fitting which had finally failed in tensile overload.

82-025 1 38


83/102 ACC MA 16/11/1983 BIX WHARENUI STN

At the completion of a sowing run the pilot flew the aircraft in a steep turn to position for a further run on the reciprocal track. during the turn he heard a 'bang' from the rear fuselage area and decided to jettison the remaining load and land the aircraft. inspection of the aircraft after landing revealed that its rudder had folded a fore and aft crack.

83-104 1 38

92/3231 ACC CR 9/10/1992 BDS Wainui Hit wire, damaged fin RUDDER FIN 242340 93 1 39

92/3810 ACC MA 13/11/1992 BOF Orini Encountered severe downdraft, hit wires

FIN & RUDDER

1 40

95/317 ACC CR 16/02/1995 BPY NGATEA FIN FOUND 500M FROM CRASH SITE. VERTICAL STABILISER. PILOT ATTEMPTED TO LAND, LOST CONTROL = CRASHED.

Fin attach fitting

243017-2 1 41

97/1451 DEF MA 11/04/1997 CZA WANGANUI

The elevator hinge attaching to the fuselage on the left hand side broke cracking around the rear bulkhead. This caused a complete separation of the hinge from the bulkhead.

Elevator hinge

1 42

01/3269 DEF MA 20/09/2001 EGV Dargaville The pilot reported that the rudder pedal suddenly locked into a fully deflected position. He managed to land safely at Dargaville where he discovered that the whole tailfin had rotated through 180 degrees on its remaining bracket and was hanging off.

1 43

02/1578 DEF MI 16/04/2002 EGS Feilding Investigation of fin IAW DCA/FU24/173 found scratches and scoring around skin.

Forward skin of Fin

242308-2 1 44


02/1167 ACC CR 18/04/2002 EGO 6 SSE Masterton

The tail fin separated in flight; the aircraft struck a ridge and caught fire. The pilot was killed and the aircraft destroyed.

Tail fin (vertical stabiliser)

1 45

03/1899 DEF MI 29/06/2003 EMN Gore The 'flutes' between the elevator hinge P/N 242235 and fitting P/N 242237 were found cracked.

Main beam web

242208 1 46

03/1964 DEF MI 2/07/2003 DUJ Masterton Several cracks were found in leading edge and central rib of the tail fin of a Walter powered Fletcher when it was removed for painting.

Tail fin 1 #REF!

03/2967 DEF MI 26/09/2003 EUH Wanganui Bad corrosion was found on the vertical fin leading edge skin, in the area of the front mount bulkhead, during the aircraft's first 100 hour inspection.

Corrosion 242308-2 1 #REF!

03/3295 DEF MI 13/11/2003 DUJ Masterton Multiple cracks were found in the skin and internal ribs of the airframe. This is a Walter Fletcher.

Multiple cracks

1 #REF!

04/3155 DEF CR 29/09/2004 JLU Masterton It was reported that the pilot heard a loud bang whilst in flight. The aircraft landed safely and was inspected by an engineer. The investigation revealed that the main wing spar web had fractured.

Wing Spar Web

234 1 #REF!

05/3727 ACC CR 22/11/2005 DZG Whangarei RCCNZ reported that the aircraft was carrying out a transit flight from Kaikohe to Whangarei and was reported to be missing. After an extensive search the aircraft was found destroyed in Pukenui Forest.

1 #REF!


06/556 DEF MA 8/02/2006 JLU Masterton The internal ribs of the Walter Fletcher vertical stabiliser were found to be broken and cracked.

Internal Ribs 242340 1 #REF!

06/2830 DEF MI 14/07/2006 CML Hamilton A crack was found on the fin leading edge skin starboard side between the leading edge and middle rib doubler P/N 242337R. The crack was on the doubler centre line in a horizontal direction and about half an inch long

Leading edge skin

242308 - 2 1 #REF!

06/3094 DEF MI 15/08/2006 DJE Nelson While the aircraft was in for a scheduled 100 hour inspection a large number of 'working rivets' were noticed on the stabilator.

stabilator 1 #REF!

06/3537 DEF MI 7/09/2006 EMT Palmerston North

Whilst complying with DCA/FU24/ 176 cracks were found on the leading edge skin from working rivets. Chafe marks made by the dorsal fairing were also evident.

Leading edge skin and ribs

1 #REF!

06/3543 DEF MI 20/09/2006 EGI Gore It was reported that the aircraft was under going 4 yearly inspection when the leading edge fin was found to have crack in it.

Leading Edge Fin

242308-2 1 #REF!

70/33 ACC MA 10/03/1970 CTI HASTINGS While the aircraft was making a normal landing the right undercarriage leg separated. the aircraft slewed to the right, incurring substantial damage.

2147 2 1


70/72 ACC MA 10/08/1970 CFQ TAURANGA During takeoff an undercarriage leg separated but remained attached to the aircraft by the brake line. the underside of the aircraft was damaged by the loose wheel during the subsequent landing. separation of the leg was due to a torque link bolt failure.

2152 2 2

70/76 ACC MA 25/08/1970 BXZ TUTIRA While making a lefthand turn to position for takeoff during topdressing operations from a steep strip, the left wheel brake failed and the aircraft swung to the right into scrub, eventually coming to a sudden stop against a tree near the lower end of the strip. pin-hole corrosion was found in the brake line (part no. ja/fu24/38-2) and had resulted in loss of fluid.

2154 2 3

72/29 ACC MA 25/02/1972 BIK TWIN BRIDGES

Failure of the lower steering tube resulted in a violent nose-wheel shimmy during the landing roll. this caused the check cables to fail and allow the oleo piston-nose-wheel assembly to separate from the aircraft.

72-025 2 4

74/27 ACC MA 24/02/1974 BHJ TAIHAPE Just after a touchdown on an uphill slope the nosewheel tyre burst causing damage to the nose leg and firewall before the aircraft could be brought to a stop.

74-061 2 5


76/18 ACC MA 21/01/1976 DEQ PALMERSTON NTH

The left hand wheel assembly separated from the aircraft at liftoff due to failure of the brackets (p/n 245146) which attach it to the scissors link.

76-014 2 5

76/41 ACC MA 9/03/1976 BHY WHANARUA BAY

During a takeoff run the starboard undercarriage leg collapsed due to a fatigue failure of one of the lower clamping bolts. loss of tension in the bolt and operation on rough airstrips was the probable initiating factor in development of the fatigue crack.

76-037 2 6

77/45 ACC MA 12/03/1977 CMK PAHIATUA Following an 'explosion' during the takeoff run a persistent vibration influenced the pilot to jettison the load and make a forced landing straight ahead. the vibration resulted from a nosewheel tyre blowout.

77-045 2 7

77/71 ACC MA 11/05/1977 CWQ WAIRAMARAMA

During the landing roll the left wheel separated from the aircraft due to the failure of the 3 bolts attaching the lug to the piston. one of these bolts had broken some time previously.

77-074 2 8

77/137 ACC MA 25/11/1977 BIK NR GISBORNE

The right mainwheel separated from the airframe during takeoff. the pilot returned to gisborne airport and made an uneventful emergency landing.

77-137 2 9


78/55 ACC MA 28/03/1978 DYX NR KAITAIA After a normal touchdown, one undercarriage leg slowly collapsed. four attaching bolts had sheared in overload probably as a result of the wheel hitting a small ridge several days previously.

78-059 2 10

78/56 ACC MA 28/03/1978 DEQ MILTON On the first flight of the day the pilot selected a takeoff heading which resulted in the aircraft travelling over two pronounced depressions to the right of the correct takeoff path. contact with the far slope of these depressions resulted in substantial damage to the left undercarriage and adjacent wing area.

78-065 2 11

78/57 ACC MA 29/03/1978 CBE TE AKAU During a break in operations, two sheep followed some resupplying fertiliser trucks onto the airstrip. the pilot failed to check the convex strip was still clear of stock prior to recommencing operations and the aircraft struck one of these sheep on the first takeoff. one undercarriage leg collapsed during the subsequent landing at the base aerodrome.

78-052 2 11


78/84 ACC MA 27/06/1978 DUH OTAMARAKAU

The right wheel fell from the undercarriage on liftoff and the aircraft settled onto one flap during the subsequent landing. the lower scissor bolt had sheared, having been weakened when the wheel struck an obstruction on an earlier occasion.

78-087 2 12

78/141 ACC MA 31/10/1978 BHK KUROW One of the aircraft's tyres was punctured by a sharp stone during takeoff. in the subsequent landing with a flat tyre, the aircraft slewed into an adjacent fence, and the undercarriage collapsed.

78-142 2 13

79/114 ACC MA 26/09/1979 DJF SPRINGS JNCTN

The aircraft sank after liftoff and the left main wheel struck some ditch diggings damaging the undercarriage. on landing the damaged undercarriage leg separated from the wing

79-117 2 14

80/102 ACC MA 19/09/1980 EMA NR OAMARU

The left undercarriage leg collapsed after landing. one attachment bolt was found to have been partially fractured before landing and the final failure of this bolt resulted in overload failures of the remaining bolts.

80-111 2 15

81/55 ACC MA 10/05/1981 EMD TIRAUMEA When the aircraft was approaching to land in gusty wind conditions it struck the ground heavily just before the threshold and the right main undercarriage separated from the wing.

81-054 2 16


82/65 ACC MA 13/07/1982 DSL MAUNGANUI

A brake caliper failed on landing. to avoid over-running the strip and going down the steep hillside the pilot deliberately collided with the fertiliser bin.

82-066 2 16

84/14 ACC MA 1/02/1984 CLO MAHOENUI During the takeoff run the aircraft started pulling to the right so the pilot jettisoned the hopper load. the aircraft then became airborne norm ally but when it landed its right mainwheel fell off.

84-012 2 17

84/85 ACC MA 24/08/1984 DUH NR TANEATUA

Several sheep were standing near the threshold of the strip when the aircraft arrived overhead. the pilot attempted to land over the sheep but a wheel hit one damaging the undercarriage leg which folded rearwards.

84-086 2 18

85/37 ACC MA 19/04/1985 EGS NR MASTERTON

As the aircraft became airborne the right hand main oleo leg separated from the wing. the aircraft was landed at masterton aerodrome but the wing flap was damaged at the end of the landing run

85-040 2 19

86/44 ACC MA 12/05/1986 EGU WHANGAREI AD

While landing at his base aerodrome during evening civil twilight, deteriorating light conditions caused the pilot to misjudge his roundout. the nosewheel struck the ground just short of the runway and collapsed. the aircraft slid onto the runway on its nose.

86-043 2 20


86/54 ACC MA 4/07/1986 EMD IHURAUA The right tyre burst during takeoff. aircraft ran off the side of the airstrip and down a steep bank.

86-055 2 21

88/7 ACC MA 11/01/1988 JAC NR KAIKOHE

During takeoff an undercarriage bolt failed causing a swing to the left. the aircraft became airborne off the side of the strip and was landed on two wheels at its base aerodrome.

88-007 2 22

88/35 ACC MA 8/04/1988 EMO OTAMAURI A tailwind caused the aircraft to sink after takeoff. the left main undercarriage struck a bank and separated from the aircraft.

88-035 2 23

89/48 ACC MA 11/05/1989 BIV HIKATAIA The aircraft's left undercarriage leg rotated in azimuth on the takeoff run on a sloping airstrip. the pilot was unable to prevent the aircraft running off the strip and plunging down a 75 m drop. the main undercarriage leg had failed due to a previous overload.

89-049 2 23

89/85 ACC MA 29/10/1989 EGW NR OPUNAKE

During takeoff the left tyre blew out causing the aircraft to swerve. the pilot abandoned the takeoff but was unable to stop the aircraft before it struck a ditch and a bank where it came to rest.

89-089 2 24


90/88 ACC MA 18/06/1990 JAL NR RUAWARO

After takeoff the left main wheel and piston assembly detached from the aircraft. the fletcher was flown to hamilton aerodrome where it was landed without further damage. the lower link attachment bolt had failed due to torsional fatigue caused by the bolt binding in its surrounding bush.

90-090 2 25

90/107 ACC MA 19/09/1990 DMS Glen Lyon Nose gear collapsed after landing 2 26

92/1942 INC MA 28/06/1992 DMV INBOUND FIELDING

RECEIVED JOINING INSTRUCTIONS FOR LEFT BASE RWY 7. PIC ADVISED HAD NOSE WHEEL PROBLEM. A/C LANDED SAFELY AT 2055

2 27

94/1205 INC MA 26/02/1994 CKA TAHAROA . Port wheel 2 28

94/4476 ACC CR 24/11/1994 JAC Kaikohe Ad Undercarriage collapsed UPPER LINK BOLT

AN6-26 2 29

94/4454 INC MI 1/12/1994 EMT NEW PLYMOUTH

PILOT RANG TO ADVISE ARRIVING WITH POSSIBLE FLAT TYRE. LANDED NO PROBLEMS

2 30

94/4689 DEF MI 16/12/1994 DZN WANGANUI

NOSE WHEEL STEERING LINKS 245235 2 31

95/1002 ACC CR 12/04/1995 DLQ NEW PLYMOUTH

JOINS OVERHEAD NORDO OBSERVED PORT UNDERCARRIDGE MISSING EMERGENCY SERVICES ACTIVATED. AIRCRAFT LANDS SUCCESSFULLY.

Bolt 2 32


95/2830 DEF MA 14/08/1995 MAT S WHITIANGA

During take off run top undercarriage leg socket Part No. 245106 failed (right mainwheel), allowing wheel to rotate 90¦. This caused loss of directional control. Oleo subsequently dropped out of cylinder and aircraft came to rest with one wing resting ong round.

LUG & BOLT 245106 2 32

96/1589 ACC CR 4/05/1996 EMT Parihaka At lift off the starboard main undercarriage separated from the acft due to failure of the upper bolt. On the subsequent landing the starboard outer panel was damaged after contacting an earth bank. subsequent minor damage to rib end of centre section as sembly found.

Torque link bolt

2 33

96/1878 DEF MA 17/06/1996 EGU NGAROMA A 'bang' was heard from nose gear vicinity on rotation, rudder peddles felt different, from past experience I was aware the steering linkage had broken. Ascertained nose gear was still on aircraft (shadow on ground), made decision to proceed to Hamilton f or repairs.

LINK ASSY 245235 2 34

96/2414 ACC MI 7/09/1996 DHD Pourere Road

Landing uphill on topdressing strip, in sink, hit lip of depression in strip. RH u/c leg collapsed.

2 35

96/3572 DEF MA 7/12/1996 CZA WANGANUI

Brake Disc. Corrosion around weld area attaching cup shaped mild steel pressing to disc, causing failure and separation of disc.

Disc 2 36


97/650 DEF MA 14/02/1997 DHE AUCKLAND The incoming crew reported the aircraft was slow to taxi and required more power than usual. A noise was heard when applying the parking brakes. On a walk around the crew found that the number 4 main wheel inner shaft was fractured.

Wheel 2605759 2 37

97/1316 INC MI 22/04/1997 BOG LUMSDEN Suspected acft starboard wheel missing. Local standby implemented. Acft landed successfully with all wheels intact. Emergency services stood down.

2 38

98/3041 ACC CR 10/11/1998 EUF Geraldine ZK-EUF(Fletcher) had just finished doing some top dressing and was landing on a strip. Once the aircraft's wheels touched the ground the nose leg gear collapsed causing substantial damage to the aircraft.

2 38

99/234 ACC MA 8/02/1999 DZC Paturau The aircraft approached in a slight downwind and encountered a downdraft close to the ground. The pilot undercorrected and the right main landing gear became detached when it touched down short of the airstrip. The right wing was damaged as it settled ont o the strip surface.

2 39

00/92 ACC MA 17/01/2000 DUJ Wangaehu V

On landing the front oleo collapsed, and the aircraft flipped.

2 40


00/1002 DEF MI 15/03/2000 DEQ NORTHLAND

�An inspection was carried out as required by DCA/FU24/142A and cracking was found around the torque tube bearing face.

Torque tube 245259-4 2 #REF!

00/2483 DEF MI 27/03/2000 DEQ KOHUKOHU

Once the aircraft touched down it began to roll to the left followed by the right wing moving down contacting the ground. Pilot was unable to raise the flaps in time and aircraft suffered minor damage to flaps and outer wing panel. A visual check confir med that the right main undercarriage leg had come off.

Lug bolts AN5-36A Lug 245106 2 #REF!

01/2216 DEF MI 28/05/2001 DZN Wanganui The right hand brake calliper mount broke while the Fletcher was turning in the loading area.

Brake caliper mount

2 #REF!

01/3898 DEF MA 5/10/2001 LTF Wanganui While taxiing on a farm strip the nose wheel steering link shaft broke off at the lower pin clevis hole.

Steering link 2 #REF!

01/3701 DEF MA 30/10/2001 EME Dargaville As the Fletcher Fu24 took off the left lower undercarriage leg, piston and wheel fell off.

AN6 bolts 2 #REF!


01/4100 ACC MA 12/12/2001 EGO Rangitumau

The pilot was positioning the aircraft for agricultural operations, and was making his first landing for the day on the strip. The one-way strip was relatively short, and the pilot anticipated poor braking action because of the long, dewy grass. On touch down, the left main undercarriage struck a sharp lip at the threshold of the strip; the lip was concealed by the long grass. The undercarriage leg separated from the aircraft which slid to a halt on its left wing.

2 #REF!

02/75 ACC MA 15/01/2002 DDW Waikaia While on take-off roll, it seemed that a tyre blew out, slewing the aircraft off the strip. The right undercarriage leg folded and there was also damage to the righthand flap. There was only half a load onboard.

2 #REF!


02/2051 ACC MA 2/05/2002 EFM Masterton The left hand main undercarriage collapsed on landing on a farm strip after the top sissor link attachment bolts snapped.�Damage was sustained to the left hand undercarriage, outer wing, aileron and flap. Repairs were carried out to enable the aircraft t o be ferry flown back to Masterton. Extensive repair work was carried out at Masterton including disassembly of the centre wing.

Top sissor link bolt

AN6-26 2 #REF!

02/1581 DEF MI 13/05/2002 CCT Hamilton The top undercarriage link bolt broke in half when the a/c was turning on muddy ground. It was sent for analysis and replaced.

Top link bolt MS 21250-06036

2 #REF!

02/1643 DEF MI 15/05/2002 EGK Wanganui The left undercarriage leg had leaked out its hydraulic fluid and lost its pressure. Inspection revealed a crack below the lower clamp.

Main U/c cylinder

24 5120 2 #REF!

02/3585 DEF MI 14/11/2002 DZN Stratford The port tyre blew on takeoff. The pilot was unaware and contiued the sortie normally and on landing was able to maintain directional control.

Tyre 2 #REF!

02/3428 DEF MA 25/11/2002 EMG Owaka The aircraft had just landed when the port undercarriage leg collapsed causing minor damage. The pilot was not injured.

Scissor link lower bracket.

2 #REF!


02/3689 ACC MA 19/12/2002 DZC Nelson Significant event. The pilot was engaged in topdressing when just after take off from the airstrip the pilot realised that the port main landing gear was missing. The pilot flew to Nelson Airport where he made a sucessful landing on the remaining underca rriage.

Scissor Link Top Bolt

2 #REF!

03/1339 ACC MA 4/02/2003 CZB Ashhurst The pilot noticed a major vibration from the left wheel during the take off so the load was dumped. As the aircraft became airborne he noticed in the mirror that the main left wheel and oleo had fallen off

Lower torque link bolt

AN6-53 2 #REF!

03/825 INC MI 17/03/2003 DMU Napier During the landing rollout the pilot had difficulty steering the aircraft.

Not established

2 #REF!

03/958 DEF MI 23/03/2003 JAL Hamilton JAL hit a rock on takeoff breaking the caliper attach pins and the hose fittings from the cylinder assembly.

2 #REF!

03/2968 DEF MI 26/09/2003 EUH Wanganui The left main under carriage cylinder and clamp were found badly corroded during this new aircrafts first 100 hr check.��

MLG Cylinder 2 #REF!

03/3040 ACC MA 26/10/2003 JLU Bideford As the aircraft took off it sank back onto its right main undercarriage, which broke the leg off the aircraft.The was load was spread and it then flew back to to Masterton and made a safe landing with no other reported damage

2 #REF!


03/3205 ACC MA 11/11/2003 JLU Hinakura Just before touchdown the aircraft experienced a down draught and struck the airstrip hard. It bounced approximately 60 meters before touching the ground again when the aircraft's nose wheel collapsed and folded back and the aircraft slid about another 6 0 meters up the airstrip on the aircraft's propeller.

Nose steering Link assyembly

245235 234 2 #REF!

04/307 DEF MI 23/01/2004 CBA Unknown It was reported that the bottom forward under carriage clamp bolt broke which allowed the outer portion of the lower clamp to go rearwards, bending the lower back bolt allowing the cylinder to go rearwards.

NAS Bolts u/c cylinder attach

2 #REF!

04/854 DEF MI 5/03/2004 EMG Gore It was reported that half of the main wheel rim broke off on take-off with load.

Hub rim broken

245240-2 2 #REF!

04/1117 ACC MA 12/03/2004 EMW Kinohaku It was reported that on roll out after landing the starboard wheel dropped into a 10 inch slump in the airstrip, resulting in the main undercarriage leg breaking at the cylinder 5 inches below the skin at the wing. The aircraft slid for 30 metres before c oming to rest.

2 #REF!

04/1639 DEF MI 26/04/2004 BDS Otapiri It was reported that the hub rim separated from the base. This was found on landing.

Wheel Hub 2 #REF!


04/1966 DEF MA 6/06/2004 EMC Hamilton It was reported that during repositioning in the hanger, a loud bang was heard. It was found that the steering post/tube assembly had fractured within the lower bearing block. It is evident that this has been fractured for some time.

Nose Steering 08-45661-1 2 #REF!

04/3632 DEF MI 28/10/2004 EFM Masterton The aircraft rolled up to the loader after landing for another load and did a right hand turn. During this turn the left brake was applied but the pedal went straight to the floor with no effect. The aircraft was therefore unable to stop so a decision wa s made to take off again. Upon return to base it was found that the left calliper was missing.

Left Hand Brake Caliper

069-00200 2 #REF!

05/354 DEF MI 5/01/2005 NZS Christchurch

The nose steering/rudder steering post was found cracked as per DCA but was found to have been bent while in service and therefore they were both at different angle positions.

steering post 245259-1 2 #REF!

05/347 DEF MI 11/01/2005 CBA Hamilton Super Air reported that the pilot noticed that there was a problem with his wheel. The aircraft was stopped and the wheel was seen to be on a slight angle. The bottom bolt had broken allowing the wheel to pivot.

Bottom Pivot Bolt

AN8-53 2 #REF!


05/374 DEF MI 8/02/2005 EGK Wanagnui It was reported that the right hand brake calliper spigot bolt broke off around the spigot bolt.

RH Brake Caliper

091-10200 2 #REF!

05/1342 DEF MI 15/04/2005 EGK Wanagnui While working off a rough strip the nose wheel steering post broke off at the lower bearing.

Steering Post 2 #REF!

05/1578 DEF MI 14/05/2005 EGK Wanganui The nose wheel steering links lower bolt broke.

Steering link lower bolt

2 #REF!

05/2021 DEF MI 25/05/2005 EML Unknown Airstrip

The Fletcher FU24 - 954 ( Walter ) inner wheel half rim broke off on the airstrip when loaded for the take off; this caused the tube to puncture.

Main Wheel 161 - 02200 2 #REF!

06/2386 DEF MI 27/01/2006 CKA New Plymouth

The aircraft's nose wheel steering link broke just as power was applied directly after loading.

Lower steering torque tube ass

2 #REF!


The nose wheel steering linkage broke on the take off roll.

Nosewheel steering torque tube

2 #REF!

06/1341 DEF MI 12/04/2006 EUH Wanganui The MLG lower torque link bolt was found to have the head sheared off.

Lower Torque Link Bolt

AN6-53 2 #REF!

06/3067 DEF MI 17/07/2006 EMW Te Kopia Super Air reported that during the landing roll the pilot found that steering was limited. On inspection it was found that the nose leg had a broken tube on the steering linkage assembly and one of two safety wires were almost broken through and only hold ing by only a few strands.

Nose Gear 245207 2 #REF!


06/2937 DEF MI 3/08/2006 EMW Hamilton Super Air reported that the pilot was unable to steer the aircraft during the landing sequence. It was later found that the tube assembly was broken.

Nose wheel steering

245207 2 #REF!

06/3431 DEF MI 31/08/2006 WLN Lawrence It was reported that the aircrafts undercarriage leg broke off abbout 50mm above the axle after a normal landing.

RH undercarriage piston

11-40009-1 2 #REF!

06/3385 INC MI 10/09/2006 WLN Evans Flat Just after the aircraft had landed the right main landing gear bottom half broke off causing the aircraft to slide a few meters before coming to rest.

Oleo 2 #REF!

06/3609 DEF MI 23/09/2006 DMU Napier One attachment lug broke from the wheel brake cylinder allowing it to detach from the main undercarriage.

Wheel brake cylinder

2 #REF!

06/4746 DEF MI 10/12/2006 EMW Waiotira When the aircraft was on the landing roll and the brakes were applied the RH brake did not work. This resulted in the aircraft narrowly missing the loader.

Main wheel inner hub

245240-2 2 #REF!

06/4830 DEF MI 22/12/2006 CML Rerewhakaitu

�During take off the pilot felt the steering through the rudder pedals change. The flight was continued as normal and the load sowed but the landing was carried out slow and short to reduce wheel slewing.

Steering Linkage Assembly

245235 2 #REF!


07/379 DEF MI 21/01/2007 EMW Purua Whangarei

During the takeoff a small bang was heard and the aircraft veered to the right. The load was spread and the right hand leg was seen to be over extended. Whilst returning to Whangarei the whole leg assembly fell out retained only by the brake hose. During landing the wheel bounced up destroying the right hand flap.

Attachment bolts

AN5-36A 2 #REF!

07/606 DEF MI 24/01/2007 EMW Purua, Northland

The aircraft was turning to approach the loading bin when a noise was heard from the undercarriage.

RH Main wheel

245240-2 2 #REF!

07/484 DEF MI 13/02/2007 EGV Hamilton During a routine check the main undercarriage bottom leg attachment fitting was found to be corroded on the lower surface each side of the front attachment bolt hole

MLG bottom leg attach fitting

245106 2 #REF!

07/4050 DEF MI 24/10/2007 EMQ Karitane The aircraft was loaded and taxiing when the RH main wheel assembly appeared to give way. Engineering investigation revealed that wheel outer hub half had failed around the rim circumference.

Outer wheel half assembly

162-02000 2 #REF!

07/4762 DEF MI 15/12/2007 EMW Rotorua Super Air reported that over a 20 hour flight period during early December 07, aircraft has gone through two sets of brake pads.

Brake Pads 2 #REF!

08/1316 INC MI 25/01/2008 EMW Super Air Ltd reported steering linkage broke on landing, stopped as soon as possible - assessed and flew to HN for repair.

245207/245204

2 #REF!


08/1320 ACC MI 12/03/2008 EMQ Manitoto Upon landing the left hand undercarriage leg failed resulting in the aircraft vacating the airstrip and coming to rest on the left wing with substantial damage incurred.

Oleo Cylinder 245120 2 #REF!

08/1234 ACC MA 26/03/2008 EMT Dannervirke

As the aircraft rotated for take-off whislt engaged in agricultural operations the left main undercarriage leg failed and fell from the aircraft. The pilot diverted to Dannevirke and landed safely with minor damage to the wing flap horn and stabilator.

AN5-36A Boltsx3

2 #REF!

08/1480 INC MI 4/04/2008 EMW Horohoro The aircraft was becoming airborne with the fifth load of the job when the pilot felt the LH undercarriage sink more than normal. Suspecting an undercarriage problem he contacted his loader driver and asked him to have a look at the left wheel assembly wh en he flew past,.The driver reported that the left main tyre was mostly off the rim. The pilot flew to HN for repairs and landed successfully.

L/H wheel assembly 245153

245240-1 2 #REF!

08/1539 INC MI 8/04/2008 EMW Rerewhakaitu

During the ferry flight to the first job of the day the right brake pedal pressure was lost.On landing the pedal went to the floor with brake pressure lost.�Machine was flown to Hamilton for repair.

2 #REF!


08/1695 DEF MI 16/04/2008 EMW Rotorua During pre flight PIC noticed brake fluid below the RH brake caliper. When he checked the brakes before start up the RH brake pedal pressure was lost.

MS28775-218 061-01200 2 #REF!

08/3556 ACC MI 20/08/2008 EGK Taranaki Wanganui Aero Work reported to RCCNZ that ZK-EGK developed a minor problem that caused aircraft to land in a field in Taranaki. Nose wheel collapsed and prop touched. Minor damage to aircraft, no injury to PIC, Engineer present. Full report to follow

PWilliams 2 #REF!

08/3917 INC MI 6/09/2008 JLU Rotorua Superair reported during the takeoff phase, a shudder was felt. Pilot continued the takeoff, sowed the load, and landed after making some checks. Found the bearing caliper had broken off, broken the tyre rim and slashed the tyre.

2 #REF!

08/4119 DEF MI 15/09/2008 DZO Waikawau Superair reported that upon landing on airstrip, scissor link on nose leg failed resulting in nose wheel being inoperable from pedal inputs, and wheel free to wander. Aircraft was in slow taxiing role; pilot was able to stop aircraft quickly therefore no risk of leaving rwy.

Tube Assy 245207 2 #REF!

97/2414 DEF MA 5/08/1997 DZN WANGANUI

Right hand outer wing panel rear mount was found broken off during a 100 hour inspection, cause unknown.

Outer panel rear mount

241311 3 1


01/2934 DEF MI 8/07/2001 CZA Wanganui During 4 yearly airframe inspection Right Hand lower outer panel mainplane mount lug was found to be badly corroded having wasted to half original thickness.

RH lowere mount lug

241573L 3 2

01/3044 DEF MA 8/08/2001 EFM Palmerston North

Exfoliation corrosion found in wing/fuselage attachments causing distortion to adjacent rearward frame on left hand side. Photos supplied. Fittings, both left and right sides have been replaced

Wing fittings 243039 & 253057-2R

3 3

05/2284 DEF MI 11/07/2005 BXS Feilding During an inspection severe wear was found in the left hand wing rear spar to the fuselage mounting attachment fittings.

Rear Spar attachment fittings

3 4

07/843 DEF MI 14/02/2007 BHK Mosgiel On inspection bracket was found with crack near bolt hole.

Rear Wing Outer Panel Attachme

241311 3 5

07/1478 DEF MI 24/04/2007 DZO Hamilton Super Air Ltd reported that the outer wing attachment fitting was discovered with a crack about 20mm long near the attachment bolt hole.

Outer Wing Rear Fitting

241311 3 5

93/5299 DEF MA 25/10/1993 DJE WANGANUI

ENGINE MOUNT BOLT LUG

24 3663 4 1

96/2980 DEF MA 21/10/1996 DZM MASTERTON

Engine mount - top left mount plate. Plate broken away from tube.

Engine mount 4 2


engine mount frame

2436663 4 3

01/1410 DEF MA 12/03/2001 EGK Wanagnui Engine mount frame top RH engine mount bolt attachment broke off leaving engine mounted on only three bolts.

Engine Mount

24 3661 4 4


01/1377 DEF MI 15/03/2001 CKA Hamilton Bracket 24664 crackedbehind the weldon the FWD plate attaching engine bolt to bracket.

Bracket 243664 LH 4 5

01/1378 DEF MI 16/03/2001 CCT Hamilton Bracket cracked see 01/1377 Bracket 243664 LH 4 6

02/3756 DEF MI 24/10/2002 DUJ Masterton The top left engine mount lug was found cracked.

Engine mount lug

196 4 7

02/3293 DEF MI 31/10/2002 DUJ Masterton Engine mount bracket installed in top R/H postion in fuselage was found broken. A crack was found to propogate from a half drilled hole.

Engine mount attachment bracke

243664 4 8

03/742 DEF MA 23/02/2003 CKA Matematonga

The pilot noticed a vibration from the engine. After landing it was found that two bolts from the right hand engine mount had come off. They were refitted and the aircraft was flown back to base for further investigation.

Engine Mount Bolt Nuts

22541N100 4 9


Two lower engine mount bolts came out due to loss of nuts. Pilot landed aircraft and nuts were replaced.

Engine mount attachment

4 10

03/1310 ACC CR 5/05/2003 DUJ nr Masterton

The pilot heard a loud bang and noticed a gap between the firewall and engine cowling of Fletcher FU24 Walter ZK- DUJ He landed immediately and found the top left hand engine mount to firewall attachment bolt had failed allowing the engine and mount to b e displaced.

Attachment bolt

NAS6606-56

4 10


03/1889 DEF MI 24/06/2003 EMG Gore The pilot noticed that a one of 15 rivets were missing from the top left engine mount bracket and two were loose.��

Rivets 4 11

04/643 DEF MI 18/02/2004 EMG Gore A crack was found in the engine mount upper left attachment lug starting at the lower edge and propagating upwards.

Attachment lug

TCC07-001 4 12

05/2918 DEF MI 8/09/2005 JSW Gore It was reported that the right hand bottom mount on the fire wall was found to be broken.

Bottom RH Engine Mount

243665r 4 13

06/4372 DEF MI 22/11/2006 EMN Gore Pheonix Aviation Maintenance Ltd. reported that the lefthand engine mount on EMN's firewall was broken during the aircraft's 100 hour inspection.

Engine Mount

4 14

07/225 DEF MI 17/01/2007 JSW Gore During a routine 100 hour inspection, the righthand engine mount was found cracked.

Engine Mount

TCL 02-008-1

4 15

07/1137 DEF MA 2/04/2007 Auckland The pilot reported that the aircraft expereinced vibration and flutter during the cruise, approximately 400 nm west of Auckland. A PAN PAN call was made a decision was made to return to Auckland. Vibration remained until landing but became less noticeable as airspeed was decreased.

Strut support 4 16


07/1292 DEF MA 3/04/2007 JNX Te Akau The Operator reported that the an engine mount bolt broke causing the engine to tilt 50mm during the takeoff run. This in turn jammed all the engine controls which prevented the pilot from shutting down the engine or feathering the prop. He jettisoned the load and ground looped the aircraft. He stayed in it until it was stropped to the ground and shut down later.

Engine attachment bolt

NAS 6606-56

4 16

07/2577 DEF MI 18/07/2007 EMG Gore Phoenix Aviation reported that a crack was found at the aircraft's engine mount.

Engine Mount

TCL-02-010-2

4 17

07/3284 DEF MI 30/08/2007 WLN Taieri During a routine inspection, a small crack was detected originating from the top outboard radius of the top LH engine mount bracket in the fuselage.

Top LH Engine Mount Bracket

TCL 02-010-2

4 18

07/3702 DEF MA 27/09/2007 EUF Geraldine The aircraft aborted the takeoff due to the top left hand engine mount bolt nut failing.

Attachment Bolt and Nut

MS 21043L6 Nut

4 19

01/1631 DEF MI 6/04/2001 DUJ Masterton As part of a turbine engine conversion extra fuel tanks were fitted outboard of the original tanks. Over time a metal panel between the tanks has chaffed against the welding in the fuel tanks body

Fuel Tanks 5 1

01/2958 DEF MI 24/07/2001 DUJ Masterton Report of frequent "Beta" solenoid failures when in flight in the approach regime.. If pin is not fully engaged then the coil burns out.

Solenoid 5 2


02/1052 DEF MI 2/10/2001 CBA Hamilton The radial flow compressor casing was found cracked. This is a known defect.��

radial flow compressor casing

M601-154-8

863036 5 3

01/3702 DEF MA 30/10/2001 CML Tahuna The pilot reported that the aircraft experienced a significant power loss just after takeoff on his 4th sortie of the day. He jettisoned the load and turned back but realised the power available was not sufficient. He made a successful emergency landing i n a nearby paddock.

Jam nut 5 3

01/3939 DEF MI 12/11/2001 DZG n/k After the fuel pressure low pressure light came on, pilot then spooled the engine down to 40% and carried out a precautionary landing back onto the airstrip.

fuel filter drain

5 4

02/1054 DEF MI 14/11/2001 DUJ Masterton The radial flow compressor casing was found cracked. This is a known defect.

Radial flow compressor

M601-154-8

873006 5 5

02/1055 DEF MI 5/02/2002 JLU Hamilton Several small nicks were found on the outer circumference of the Power Turbine wheel.

PT wheel and blades

863019 5 6

02/1539 DEF MI 8/05/2002 EFM Masterton While maintenance was being carried out inside the wing it was noticed that the cleats previously installed when modification P.A.C - FU-0299 was incorporated had been cut/removed from inside the wing. These cleats were removed when the aircraft had the Walter STC incorporated

Wing internal cleats

08 - 03066 5 7


02/3203 INC MA 8/11/2002 EUD Queenstown

The pilot reported that while climbing through 5500ft the engine started to lose power. PiC instructed the parachutists to jump out. The engine then stopped and pilot made a successful forced landing onto Queenstown airport.

5 8

02/3899 INC MA 18/11/2002 EMN Winton The aircraft had an engine failure on takeoff as a result of water contaminated fuel being pumped into the tanks from a custom built mobile fuel storage tank. The aircraft did not suffer any damage and its fuel lines were flushed out. The storage tank has now been modified by replacing the top cover seal and making the fuel drain accessable.

5 8

02/3867 DEF MA 29/12/2002 EUD Jardiines Airstrip

Operator reported that at 10ft agl engine torque dropped below 20%, with the "Power Turbine" (NG) also declining. Pilot cycled power lever to idle then full power but got no response from the engine. A set-up for landing was made, successful landing ini tiated.

FCU 5 9

03/273 DEF MA 1/02/2003 CKA Hamilton Airport

During an engine ground run, after a F.C.U. adjustment and engine at 88% torque. A loud explosion occurred followed by engine spooling down and lots of PT blade material coming out of the exhaust. Engine shut down.

Power Turbine Blade

863036 5 10


03/869 DEF MA 18/03/2003 DZG Port Waikato

While investigating a high ITT resistance it was suspected that the ITT probe broke and went out through the power turbine and damaged the blades.

ITT probe 5 11

04/2142 ACC MA 4/07/2004 JNX Hicks Bay During takeoff from an agricultural airstrip the engine stopped producing power. The aircraft was force landed without power onto a river bed with no injuries to the two crew although the aircraft was damaged.

5 12

05/32 ACC MA 12/01/2005 EFM Mauriceville

During take off the aircraft's engine burst into flames. The aircraft then veered off the strip and through a fence, damaging the propeller.

Comp. turbine blades

844042 5 #REF!

05/184 DEF MA 17/01/2005 EMG Gore The Walter powered Fletcher had a major engine failure while it was taxiing on the ground.

GT guide vane supporting ring

894004 5 13

06/696 DEF MA 27/02/2006 NZS Pudding Hill

The aircraft was climbing out and established on a crosswind heading at 800 feet when a loud bang was heard followed by total power loss. A landing was then made on an adjacent runway. Minor damage was sustained to the flap on touch down.

Compressor turbine blades

893013 5 14


06/999 DEF MA 16/03/2006 JLU Danevirke When power was being applied for take off a loud howling sound was heard from the engine. The take off was subsequently aborted. Inspection revealed that the tip of one power turbine blade was missing.

Power turbine

883004 5 15

06/1417 DEF MI 15/04/2006 DJE Nelson It was reported that during a non routine boroscope inspection, damage was noted along with a piece missing from the number 1 compressor turbine blade and also what appeared to be cracking in the compressor heat shield.

Outer flame tube

863035 5 16

06/2183 INC MI 11/06/2006 JNX Hamilton Airways reported that ZK-JNX was a VFR flight into NZHN. On landing on grass RWY25, the aircraft was observed to strike a threshold marker board. The pilot advised that the flight had suffered minor engine problems.

Fuel Control Unit

LUN6590.03-8

881023 5 17

06/3198 DEF MI 25/08/2006 EMQ Moutere Station

It was reported that the engine lost power on takeoff and the pilot landed the aircraft and went through a fence. Minor damage was sustained to the propeller, tail cone and wing skin.

Fuel control unit FCU

5 18

06/3428 DEF MA 11/09/2006 DUJ Masterton During the ground run after a compressor wash the engine blew up. Flames and smoke were observed coming from the exhaust ducts.

GT guide vane ring

852052 5 19


06/3606 DEF MI 20/09/2006 CCT Hamilton During a scheduled inspection of the Walter turbine engine the ITT probe mounting bushings were found to be loose.

ITT Connection bushing

5 19

06/4630 DEF MI 4/12/2006 EUF Unknown During beta operation while taxiing after landing the "BC" lever failed.

BC Lever 5 20

07/2059 DEF MI 17/04/2007 CCT Hamilton It was reported that during the climb out from takeoff from runway 25L the aircraft experienced loss of power and was forced to return for landing. Unanymous

5 21

07/1280 DEF MA 18/04/2007 EMW Maungaturoto

The PT6 turbine engine experienced an uncontrollable overspeed on the turbine. To prevent the airspeed from exceeding the redline the pilot had to shut the engine down and start a glide back to home base. He then had to restart the engine several times to gain height and get close enough to carry out a dead stick landing.

5 22

07/3172 DEF MI 26/08/2007 EMN Pilot reported engine down on power.

5 23

08/334 INC MI 17/01/2008 JNX Raglan Superair Ltd reported PIC noticed occasional squeak on takeoff which gradually increased to most phases of flight, mainly takeoff and landing in turbulent flight. Flew to Hamilton base for investigation.

5 24


08/315 ACC MA 30/01/2008 JNX Raglan The pilot reported that just before he rotated there was a bang from the engine and he saw flames. The aircraft passed through two fences before coming to a stop down an embankment. The pilot vacated the aircraft before it was destroyed by fire.��PIC (K evin Young) reported earlier this month (21/01/08) that he noticed occasional squeak on takeoff which gradually increased to most phases of flight, mainly takeoff and landing in turbulent flight. Flew to Hamilton base for investigation.

5 25

08/2327 INC MA 22/05/2008 EME Hamilton On the first takeoff after a 150 hour inspection the engine did not produce full power. The pilot elected to continue the take-off and circuited for an uneventful landing

5 25

08/2439 DEF MI 4/06/2008 EGW Super Air Ltd reported that engineers has reported the FCU Finger filter had been fitted back to front sometime in the past. Found on check.

5 26

70/34 ACC MA 10/03/1970 CDX WHATAWHATA

When the pilot closed the throttle prior to landing, the engine stopped. a forced landing was made in a ploughed paddock beyond the end of the strip.

2107 6 1


70/90 ACC MA 10/11/1970 BVU WHATAWHATA

During a topdressing operation, engine lost power and stopped, meaning a forced landing on unsuitable terrain. pilot admitted he omitted to refuel aircraft. the aircraft would normally have been refuelled at base and end of previous day but underground tank was empty and pilot going to refuel from loader vehicle at strip in morning. sufficient fuel to reach a.s but need to refuel overlooked.

2170 6 2

71/34 ACC MA 24/03/1971 CRX MANGAITI Engine stopped through fuel exhaustion during a topdressing sortie. pilot attempted down-hill landing on the strip but found it impossible and the aircraft collided with a hedge and plunged into a gully.

71-032 6 3

72/86 ACC MA 13/09/1972 CLM NGAROMA Just after takeoff on a topdressing sortie the engine failed completely. the load was jettisoned and a heavy landing made in hilly country. strip examination of the engine revealed a fatigue failure of the crankshaft gear disrupting the drive to the camshaft and

t

72-082 6 4


73/56 ACC MA 29/03/1973 CKJ L ROTOMAHANA

Following a power loss the pilot attempted a forced landing on a relatively level hilltop, but during the roll the nosewheel entered a deep depression and was forced rearward and upward into the cockpit floor. fire broke out in the engine bay immediately thereafter and flashed back into the cockpit as the pilot opened the canopy to escape.

73-049 6 4

73/87 ACC MA 20/07/1973 BXZ PARIHAUHAU

An engine failure due to a failed piston pin necessitated a forced landing in a small paddock in steep hill country. seeing that we would be unable to stop the aircraft from over-running the paddock and capsizing in a deep gorge, the pilot intentionally guided the aircraft into a tree. his action prevented destruction of aircraft and serious injury or death to both occupants.

73-089 6 5


73/130 ACC MA 29/10/1973 CDW NR ORAKEI Earlier that day 2 forced landings resulted from severe engine vibration and power loss shortly after takeoff. ground runs after rectification work indicated that engine was operating normally. after takeoff from a field, reoccurrence of fault momentarily confused pilot. aircraft stalled and struck ground in incipient spin. sticking valve probably caused rough running

73-129 6 6

75/3 ACC MA 2/01/1975 CBA MATAPARA When the aircraft engine ran roughly a forced landing became necessary. a heavy landing on a soft surface caused collapse of the noseleg. the engine malfunction was due to fuel starvation. due to an incorrectly routed fuel line, 4 gallons remaining in the tank was unusable.

75-016 6 7

75/87 ACC MA 9/08/1975 BYC NR TE MATA

During a spraying run the engine ran roughly and a forced landing was made on a gorse-covered ridge. the top piston ring of one cylinder had broken and pieces of ring were found throughout the engine. one piece lodged under a valve is believed to have caused the malfunction.

75-085 6 7


75/116 ACC MA 28/10/1975 DUG KAIMAI En route to the sowing area the engine stopped and a forced landing was made in a small paddock, the aircraft then passing through a fence. incorrect application of sealant material when the fuel sender units had been replaced had allowed some of this material to enter the tanks and had blocked the outlet of both tanks, thus depriving the engine of fuel.

75-113 6 8

76/93 ACC MA 17/08/1976 EFS NR MOENJODARO

Location: nr moenjodaro, pakistan. while the aircraft was on a spraying run at low level the engine cut without warning.

76-090 6 9

77/81 ACC MA 11/06/1977 DHY WAIMANA On takeoff after the aircraft had been refuelled, a bang was heard and the engine lost power. a forced landing was carried out in a swamp. a large quantity of water was drained from the aircraft's fuel system.

77-083 6 10

77/86 ACC MA 23/06/1977 DHD SCARGILL The castellated nut on the throttle butterfly shaft vibrated loose and engine power suddenly reduced to idle during a sowing run. in the ensuing forced landing the aircraft rolled into a ditch incurring substantial damage to the nose section.

77-090 6 11


78/82 ACC MA 12/06/1978 CBA TE AKAU During a sowing run the aircraft's engine spluttered and then stopped, necessitating a forced landing in rough country.

78-081 6 12

79/47 ACC MA 7/03/1979 CDX NR TE ANGA

Shortly after liftoff the aircraft's engine cut due to fuel starvation. uneven fuel feeding was evident on the fuel gauges. a bee was found jammed in the outlet of one tank causing the uneven fuel feeding and subsequent fuel starvation.

79-045 6 12

79/151 ACC MA 10/12/1979 EHX NR OWHANGO

During the takeoff run an engine power loss caused the takeoff to be abandoned. the aircraft could not be stopped within the remaining airstrip length and slid sideways into a ditch. the power loss was probably caused by a vapour lock in the fuel system.

79-148 6 13

82/48 ACC MA 28/04/1982 JAA PUKAPUKA Following an engine failure the pilot made a forced landing during which the aircraft ran over a bank. the engine failure was caused by a fatigue failure of a connecting rod.

82-049 6 14


82/50 ACC MA 5/05/1982 DZN WAIMIHA On the 21st takeoff that morning, the engine stopped because of fuel exhaustion. a forced landing was made straight ahead between obstructions. the pilot's attention was distracted from the aircraft's fuel state by a freshening tail wind which he knew could cause difficulty when operating from this strip.

82-052 6 15

87/60 ACC MA 9/06/1987 VAL PATOKA The aircraft was damaged during a forced landing after fuel pump failure.

87-064 6 16

87/109 ACC MA 25/11/1987 BOE CHASLANDS

At the commencement of a sowing run the engine began to 'over rev'. and shortly afterwards it stopped. during the ensuring forced landing the left undercarriage leg was torn out. a strip examination indicated that the oil gallery to the engine's no. 3 and no. 4 main bearings had been blocked resulting in failure of the no. 7 connecting rod.

87-119 6 17

90/134 ACC MA 10/12/1990 BIX Rotomahana Block Ad

Power loss, thistles jammed aileron, control lost. Refer to TAIC report 90-011T.

90-011T 6 18

91/640 INC MA 23/09/1991 CML ROCTR SHORTLY AFTER TKOF ACFT EXPERIENCED ROUGH RUNNING ENG, LANDED RWY 01.

6 18

92/1158 INC MA 15/04/1992 CRF GISBORNE PILOT REPORTED ON FINAL WITH ROUGH RUNNING ENGINE

6 19


93/1506 DEF MA 15/02/1993 CQB MOSGIEL SHORTLY AFTER TAKE OFF AS THE A/C TURNED AT 200FT A LOUD BANG WAS HEARD. THE ENGINE RAN ROUGH.

CONNECTING ROD

6 20

93/3652 DEF MA 22/07/1993 CML NZHN COUNTERWEIGHT BUSH

73810 6 21

93/3651 DEF MA 28/07/1993 DZG HAMILTON PISTON LW10207 6 22

93/5152 DEF MA 9/09/1993 BOF KAWERAU Crankshaft 6 23

93/5987 DEF MA 14/12/1993 BIF HAMILTON AUXILIARY FUEL PUMP

8123-H 6 24

94/2736 DEF MI 9/06/1994 DLQ HAMILTON ROUGH RUNNING: LOW COMPRESSION NR5 CYLINDER

UPPER VALVE SPRING S

LW10076 6 25

94/3034 DEF MA 19/07/1994 DZD MOSGIEL MAGNETO IGNITION COIL

6 26

94/4646 DEF MI 20/10/1994 EMT PALMERSTON NORTH

LOSS OF OIL PRESSURE ON TAKEOFF.

LW11775 6 27

94/4648 DEF MI 29/11/1994 DYJ PALMERSTON NORTH

LYCOMING ENGINE IO-720 50-15/38-13

L885-54A 6 28

95/1170 DEF MA 27/02/1995 CDZ PALMERSTON NORTH

During scheduled maintenance of a Lycoming IO-720, 8 cylinder, 400 horse power air cooled engine, camshaft lobes were found to be worn after only 98 hours of service life. Two inlet tappets (numbers 3 and 4) were badly spalled, on the tappet contact are a, after only 98 hours of service life. Metal fragments were found in the oil filter element.

Camshaft / tappets

LW13879 6 28

95/702 DEF MA 12/03/1995 DZM MASTERTON

. Tubular mount

6 29


95/1164 DEF MA 22/03/1995 DBG DANNEVIRKE

No1. CONROD BOLT FAILURE. Con-rod bolt 6 30

95/1164 DEF MA 22/03/1995 DBG DANNEVIRKE

No1. CONROD BOLT FAILURE. Con-rod bolt 6 31

95/2574 DEF MA 29/08/1995 DJE WANGANUI

. Exhaust Valve Spring Cap

LW16475-KL1-0

6 32

95/2630 DEF MA 5/09/1995 DHE HAMILTON . Magneto screw

10-349652 6 33

95/3351 DEF MI 26/09/1995 EGQ PALMERSTON NORTH

. Camshaft L641-54 6 34

95/3670 DEF MA 13/11/1995 EMC WANGANUI

. Valve cap 69532 KL1-0

6 35

96/270 ACC CR 30/01/1996 EGW PIO PIO While in cruise from a farm airstrip to Te Kuiti aerodrome EGW suffered an engine failure necessitating a forced landing in a paddock.

6 36

96/1037 DEF MA 1/04/1996 DZO HAMILTON During routine inspection, metal found in oil filter.

ENGINE L690-54 6 37

96/3646 DEF MI 16/04/1996 HAMILTON Duriing routine inspection metal particles found in oil filter.

ENGINE L1140-54A 6 38

96/1150 DEF MA 22/04/1996 CBA HAMILTON During routine inspection of oil filter flat metal particles found.

conrod bearing

6 39

96/1597 DEF MA 11/05/1996 EOE NEW PLYMOUTH

0144 ZK-EOE reported south of the city joining with engine problems requesting straight in rwy 05 (opposite to duty runway). No emergency declared. Aircraft landed safely 0149.

Spark plug 6 39

96/1562 DEF MA 5/06/1996 MAT HAMILTON Conrod #2 cylinder position LW-10646.

Upper Conrod Bushing

6 40


96/3007 DEF MI 24/10/1996 EMC WANGANUI

Engine Lycoming IO-720-A1B induction pipe cracked at weld repair.

Induction pipe

6 41

97/704 DEF MI 3/03/1997 JAL HAMILTON While on a ferry flight from Pirongia to Hamilton, the engine began to misfire slightly. The aircraft was cleared to enter Hamilton controlled airspace and to descend to 500 feet. On reaching this altitude the pilot requested a climb to 1000 feet, which was given. The pilot was asked if he required RFS assistance and whether he required a left base onto an alternative grass vector. These offers were declined and the aircraft landed safely.

Spark plug RHb37e 6 42

97/986 DEF MA 3/04/1997 DZG 2NM E ROTORUA

At 0257 DZG advised engine failure and was landing in paddock just east of RO AD. Twr observed descent and landing. After landing pilot advised safe on ground.

Conrod 6 43

97/1708 DEF MI 17/04/1997 CKA HAMILTON During 100hrs check, metal found in suction filter, metal peeling off shell in round pieces.

Bearing LW13683 6 44


The engine driven fuel pump failed during flight. This caused the engine to fail. The engine was restarted using an electrical pump.

fuel pump RG17980 6 45

97/1607 DEF MI 19/05/1997 DDW INVERCARGILL

Bearing metal in filter at routine inspection traced to failure of #7 conrod bearing.

#7 Conrod Bearing

6 46


97/2575 DEF MA 20/08/1997 EGU PALMERSTON NORTH

Cylinder failure on engine fitted to ZK-EGU. Engine ran rough #5 cylinder found to have loose exhaust seat which had jammed open the exhaust valve and bent the push rod. Cylinder changed.

#5 CYLINDER L874-54A 6 46

97/2576 DEF MA 20/08/1997 CRF PALMERSTON NORTH

Engine removed due metal contamination.

PISTON AND RINGS

L615-54A 6 47

97/3124 DEF MI 14/10/1997 EUF MOSGIEL Distributor gear bush in block found very loose.

DISTRIBUTOR BLOCK

10-391588 6 48

98/1842 DEF MA 7/04/1998 DDW WOODLANDS

DURING FLIGHT OIL SPLATTERED ON TO THE WINDSCREEN. THE FLIGHT WAS TERMINATED SAFELY.�LYCOMING REPLACED THE CRANKSHAFT

Engine Casing 6 49

98/2382 DEF MI 10/08/1998 DLS PALMERSTON NORTH

Engine strip report shows signs of detonation.

Bearings 6 50

98/2939 ACC CR 29/10/1998 EUH Rahotu Towards the end of a 'sowing' sortie the fuel pressure guage indicated extreme fuel pressure. So the pilot decrease the throttle and headed back to the strip to land. Once on short finals the pilot had to increase throttle to maintain altitude, howevert he engine went to idle and this caused the pilot to stall the aircraft just short of strip threshold.

6 51

99/1009 DEF MA 17/03/1999 EUH NEW PLYMOUTH

There was a major defect found with a cylinder in the engine of the aircraft.

VALVE ROCKERS

17 F 21187 6 52

99/3145 DEF MI 27/10/1999 MAT THAMES Metal was found in both oil filters. Con Rod Bearing

74309 6 53


00/636 DEF MI 10/03/2000 DZM PALMERSTON NORTH

The engine was removed due to a knocking noise and low oil pressure. Engineering found that the oil filter had significant metal in it.

bearings L 1086-54A 6 54

01/1232 DEF MA 18/02/2001 BOG Gore The aircraft engine began rough running.

Exhaust valve LW 16740 6 54

01/1625 DEF MI 19/03/2001 EGS Masterton The number 5 bearing shells in the Fletcher Lycoming IO-720 AIB engine suffered a catastrophic failure resulting in cracking of the crankshaft. .

Main bearings

LW-13683 6 55

01/2019 DEF MA 1/05/2001 EMW Palmerston North

The engine was removed from service due to metal found in the oil filter. When the engine was stripped down it was found that the main bearings camshaft and tapppet bodies had failed prematurely and caused other engine damage

Main Bearings

LW 13683 6 56

01/2020 DEF MA 15/05/2001 EGO Palmerston North

The engine was removed due to metal contamination. It was found that an exhaust valve seat had dropped in No 5 cylinder However, it is suspected that vibration, detonation, and excessive heat had caused this in the first place.

Cylinder L886-54A 6 57

01/2206 DEF MI 21/05/2001 EME Palmerston North

The body of a brand new spark plug fractured between its threaded portion and the upper body as it was being tightened. Fifty eight plugs were returned to the manufacturer for replacement

Spark plug URHB37E 6 58


01/2028 DEF MA 7/06/2001 EGO Feilding Metal was found in engine oil filter at the second filter check after overhaul. On strip down the main front bearings were found to have delaminated.

Front Main Bearings

LW 13885 6 59

01/4052 DEF MA 15/10/2001 EGO Palmerston North

The engine was bulk stripped and the fifth order counterweight blade was found to have failed through the trailing blade bush hole.

Crankshaft counterweight bush

6 60

02/2046 DEF MI 21/02/2002 DDW Dunedin The engine had only run 2-3 hours after a complete overhaul when the pilot reported an oil leak from a crankshaft seal. Investigation revealed aluminium in the oil filter due to a failed crankshaft bearing shell.

Crankshaft 6 60

02/1218 DEF MA 15/03/2002 CCT Mahoenui During the takeoff roll the Walter turbine engine made a loud noise and emitted some smoke. The takeoff was aborted and the aircraft came to a safe stop. Engineering found that the compressor turbine had failed.

Compressor Turbine

841089 6 61

02/1177 DEF MI 20/03/2002 EUF Taieri A 3 ¾" crack was found on the Walter turbines compressor housing.

Compressor casing

M601-154.8

874037 6 62

02/1982 DEF MA 14/06/2002 EMT Palmerston North

The engine was removed following a loss of oil pressure. It was found that the oil filter housing retaining bolt had failed.

Oil filter housing

6 63


02/1983 DEF MI 16/06/2002 EMT Palmerston North

The pilot found that power would not increase above 2200rpm. Investigation revealed that a section of SCAT hose had collapsed and was restricting airflow to the engine.

Air intake ducting

SCAT 16 6 64

02/2884 DEF MI 9/09/2002 EUH Palmerston North

The engines number 4 and 6 main bearings were found to have failed prematurely due to bearing overload.

Main bearings

LW 13683-MO3

6 65

02/3350 DEF MA 17/09/2002 DZO Waikato The engine seized while the aircraft was on the ground at the loading site.�Investigation revealed that the crank case halves had fretted causing the centre main bearing to come loose.�

Crank Case Halves

RL495-54R 6 66

02/2906 DEF MI 23/09/2002 CZA Te Kuiti The left magneto was found loose during an Audit Inspection.

Magneto 6 67

02/3352 DEF MI 15/10/2002 JAL Waikato While looking for an oil leak the pilot noticed that several cylinder base studs were broken.

Cylinder base studs

76220 6 67

03/1336 DEF MA 8/05/2003 EGW near Whangarei

The aircraft was accelerating for take off when the engine suffered an internal failure that resulted in a hole being made in the top of the crankcase. The aircraft was then brought to a safe stop on the remaining part of the airstrip.

Connecting rod cap

LW 13756 6 68


03/2482 ACC MA 28/08/2003 DZM Rewarewa The Operator reported that the aircraft lost power after takeoff and the pilot made an emergency landing into a paddock. The right outer wing then hit a sheep which caused damage.

6 69

03/3011 ACC CR 23/10/2003 DUJ Bideford Operator reported that on takeoff, the engine failed. The pilot applied the brakes, but overran the airstip and went through a fence and came to rest in a bush.

Turbine Blades gas generator

6 70

03/3341 DEF MA 20/11/2003 EUC Napier PIC reports low manifold pressure and high fuel flow

induction air filter

6 71

03/3922 DEF MI 3/12/2003 DZN Palmerston North

The engineer reported excessive bearing wear, posibly due to lubrication breakdown resulting from operation of the engine in the upper range of temperature limits.

Bearings L836-54 6 72

03/3638 DEF MA 3/12/2003 DZM Masterton Pilot reported smelling oil in-flight during agricultural operations. On inspection it was found the studs had failed on a cylinder allowing it to shift from the crankcase.

Crankcase L-835-54A 6 73


03/3802 DEF MI 17/12/2003 BXZ Farm Strip The pilot reported an engine oil leak . An inspection found the top rear nut off, the bottom through-bolt broken, top middle studs broken, lower two middle studs pulled out of the case and foward stud broken. The cylinder was removed and inspected; helic oil inserts and replacement through-bolts were fitted; the oill filter was checked and no metal found; the engine was ground run and performed satisfactorily.

Cylinder Base Studs and Bolts

38.13 L852-54 6 73

04/1629 DEF MA 29/01/2004 BHK Unknown It was reported that the camshaft gear bolts were found too soft and yeilding before torques value. A similar defect was found on another Hawker Pacific batch number in 2002.

Gear Bolts STD1791 Bolt

6 74

04/588 DEF MI 15/02/2004 BHK Taieri The engine filter was found to contain metal. The engine was removed and stripped.

Con Rod Bearings

74309 6 75

04/3119 DEF MI 25/08/2004 JAL Te Kuiti It was reported that the pilot found an oil leak coming from the number 5 cylinder.

Cylinder 6 76

05/673 DEF MI 2/03/2005 EUH Wanganui It was reported that the aircraft's fuel line was found cracked and leaking.

Fuel Line 6 77

05/1303 DEF MI 17/04/2005 CRY Hamilton A new CFO-100-1 oil filter and seals were installed on the engine during a routine inspection. On starting the engine oil was pumped out of the engine from the oil filter housing and adaptor.

Oil Filter Housing Seal

CFO-203 6 78


05/2115 DEF MA 20/06/2005 SFL Port Waikato

A loud clonking noise was heard coming from the engine in flight.

Crank shaft LW-10842-85

598H 6 79

05/2336 DEF MA 22/07/2005 EMY Mount Palm

The pilot reported that the aircraft was positioned on a medium steep strip for take off after completing a job. The brakes were released and the throttle was opened. The engine suddenly died and the aircraft came to rest 15 metres from the end of the run way.

Auxiliary Air Valve.

6 80

07/1727 INC MI 11/05/2007 EGT Hawkes Bay

AG Aviation Ltd reported that engine began cutting out. Made a precautionary landing on closest airstrip. Fuel hose leaking under pressure. Had exhausted fuel tanks.

6 80

70/6 ACC MA 21/01/1970 CBG KAITAIA The pilot was testing newly installed spray gear and flying low past a hangar to allow an engineer to view the spray pattern. the pilot's preoccupation with the spray controls resulted in the aircraft colliding with a hangar, damaging the undercarriage and tailplane.

2080 7 1


70/7 ACC MA 23/01/1970 BHV KAIPARA FLTS AD

Forward visibility was reduced by rain on the windscreen. the pilot rounded out too high and the aircraft landed heavily on one side of the strip, causing the right undercarriage leg to separate. the aircraft then skidded along the strip, incurring damage to both mainplanes and rear bulkhead.

2086 7 2

70/12 ACC MA 3/02/1970 BHJ KAITIEKE A loading vehicle struck the left elevator when backing away after filling the aircraft. the loader continued to back, twisting the aircraft's elevator and badly damaging the rear fuselage assembly

2096 7 3

70/14 ACC MA 4/02/1970 CLA HEREKINO During a topdressing run, the aircraft collided with power wires of which the pilot was aware but believed he had enough height to clear. collision partially jammed the elevators and the pilot was forced to land in a restricted area, the aircraft being further damaged when its left wing struck a tree.

2088 7 4

70/19 ACC MA 13/02/1970 BVU SOUTH HEAD

A deer emerged from tall cover on the edge of the airstrip and collided with the aircraft which had just landed. the pilot was unable to take safe avoiding action

2144 7 5


70/23 ACC MA 15/02/1970 COA TUATAPERE When the pilot flew overhead, the spraying area was covered by fog and a landing was made in a paddock. owing to wet grass, braking was ineffective and the pilot was unable to stop the aircraft before it struck a fence.

2145 7 5

70/29 ACC MA 26/02/1970 CDW KIWITAHI Due to a faulty spray pressure gauge, the pilot's attention was diverted to the spray boom. the nose wheel struck rising ground and the forward part of the fuselage was damaged.

2146 7 6

70/43 ACC MA 14/04/1970 CDW HUNTLY The aircraft struck power wires which were difficult to see against a background of bush and scrub.

2149 7 7

70/47 ACC MA 21/04/1970 BVU MANGAPEHI

While the aircraft was stationary in the loading area, it was struck heavily by the loading vehicle. substantial damage to the right flap and fuselage resulted.

2148 7 8

70/52 ACC MA 7/05/1970 CMZ WHANGARURU

While flying to an operational area at sowing height, the aircraft struck a power wire, presence of which, the pilot was unaware, strung between the mainland and an island

2140 7 9

70/58 ACC MA 10/06/1970 CKB ROTOKAKAHI

The loader driver omitted to raise the loader bucket before moving toward the aircraft. the collision caused substantial damage to the fuselage.

2142 7 10


70/70 ACC MA 4/08/1970 BHY WAIMAHAKA

While a loader vehicle was backing away from the aircraft, one of its wheels sank in a depression and the loading bucket struck the top of the fuselage.

2153 7 11

70/73 ACC MA 11/08/1970 CCT TAHORA During a landing, the rear fuselage struck the ground and was damaged.

2160 7 12

70/74 ACC MA 11/08/1970 BXZ FERNHILL An inexperienced loader driver inadvertently lowered the bucket onto the top of the aircraft.

2156 7 13

70/100 ACC MA 23/11/1970 CTH NR MOSSBURN

Aircraft had been topdressing area nr lake te anau for most of day. at approx 1730 hours the pilot, with loader driver as pax, took off for winton, 47 m sse, where a start was to have been made on another job. the aircraft failed to reach destination and was located early next day in steep tussock country 1900 ft asl, 8 m from departure point. both occupants killed. the accident was caused by loss of control incurred during a very steep turn made at a height which precluded recovery.

2174 7 13

71/28 ACC MA 7/03/1971 CBE TANGOIO Aircraft collided with a power wire at the end of a sowing run. the fin was almost completely severed but the pilot maintained control and diverted to napier to make a landing without further damage.

71-026 7 14


71/52 ACC MA 14/05/1971 COB MIMIWHANGATA BY

While taking off from a razor-back strip in a cross wind the aircraft was forced by a sudden updraught under the right wing into an almost vertical bank. loss of control resulted and could not be regained before the aircraft struck a hillside.

71-050 7 15

71/53 ACC MA 18/05/1971 CBE ARGYLE EAST

While attempting his first landing on this strip the pilot misjudged his approach and allowed the aircraft to sink below strip level. the resulting impact, 12 inches below the level of the end of the strip, bent the main landing gear rearwards and caused damage to the flaps.

71-052 7 16

71/54 ACC MA 18/05/1971 BXQ TAKAPAU On completion of a ferry flight the pilot landed uphill on a 350 yard airstrip with a slight tail-wind component. the strip was wet and the aircraft could not be stopped before it collided with a fence at the top of the strip.

71-053 7 17

71/58 ACC MA 3/06/1971 CRP HALCOMBE During positioning for a spraying run the aircraft encountered an area of unexpected turbulence which caused it to depart from its intended flight path and to collide with a tree from which there would, at best, have been minimal separation.

71-057 7 17


71/80 ACC MA 29/08/1971 BVU MANGAITI During an approach to a landing under marginal conditions for the particular airstrip, wind eddies in the lee of tall trees bordering the strip caused the aircraft to collide with one of these trees 40 ft above ground level.

71-080 7 18

72/16 ACC MA 24/01/1972 CPY NR DANNEVIRKE

On arrival at an airstrip to commence a day's operation an area of sink was encountered on finals. corrective action failed to prevent an undershoot and both main undercarriage legs were dislodged when they struck the lip of the strip.

72-113 7 19

72/21 ACC MA 11/02/1972 BXT HILLEND During the third of a series of spray runs in a gorse-covered gully the aircraft collided with a power wire. control was maintained and an emergency landing made.

72-019 7 20

72/27 ACC MA 22/02/1972 BXQ KAITAIA During a ferry flight to base rapid formation of fog forced the pilot to attempt a landing on difficult terrain. a successful touchdown was made but the aircraft collided with a fence during the landing roll.

72-024 7 21


72/35 ACC MA 3/03/1972 BVA TE KUITI AD The aircraft which was picketed on the airfield was unlawfully converted to his own use by a farmer's son. it became airborne and had reached about 100 ft agl when it stalled and nose-dived into the ground. it is believed that the occupant had had no previous flight instruction.

72-029 7 22

72/45 ACC MA 12/04/1972 CFK TE AKAU On completion of a ferry flight the pilot attempted a landing on an exposed airstrip in a strong gusty crosswind. at roundout a gust of wind under the starboard wing rolled the aircraft violently onto its side. the left wing hit the strip and the outer wing panel separated. the aircraft then cartwheeled off the airstrip.

72-042 7 23

72/68 ACC MA 27/07/1972 CLI NR WANGANUI

Aerial inspection of area to be sprayed made and no obstructions observed. contour of land meant that spraying runs had to be made directly toward a low sun. towards end of first spray run, aircraft entered area of shadow and pilot noticed a solitary pine tree ahead which he could not avoid. a wing collided with tree but aircraft remained controllable and was flown back to base.

72-067 7 24


72/71 ACC MA 31/07/1972 CZC MAHURANGI

After completing an inspection of an area to be topdressed the pilot flew down a large gully. flying under a string of power wires crossing the gully the aircraft collided with another string of wires tied to the base of a pole. the pilot knew of the existence of those wires but believed they were further down the gully.

72-070 7 25

72/80 ACC MA 30/08/1972 CFQ NR FAIRLIE Loss of control occurred (precipitated by circumstances undetermined but in which the consequences of a coronary occlusion cannot be excluded) while the aircraft was in a steeply banked attitude close to the ground.

72-077 7 26

72/116 ACC MA 27/11/1972 CQB MANGARATA RIVER

While the aircraft was turning to line up with the airstrip the stabilator struck a reversing loading vehicle.

72-122 7 27

73/32 ACC MA 5/02/1973 BIH PIAKOITI RIVER

The accident resulted from loss of control at a low altitude. no evidence was obtained to suggest or show that this was due to any mechanical cause. physical incapacitation of the pilot before impact is regarded as the probable cause of the accident.

73-023 7 28


73/60 ACC MA 8/04/1973 BHJ MAKURI Operating in marginal weather conditions the aircraft encountered a gust just short of the threshold which caused the port wing to drop and the port undercarriage leg to be torn off when the wheel impacted against the runway lip.

73-050 7 29

73/124 ACC MA 14/10/1973 BWV NR MASTERTON

The pilot landed too far in on a hillside strip. lush growth reduced braking effectiveness. a ground loop was initiated but one wheel hit an obstruction and broke off. the aircraft slewed into a fence.

73-123 7 30

74/14 ACC MA 28/01/1974 DPF OTOKO On arrival at a short steep strip the aircraft landed too far in. a groundloop was initiated to avoid another aircraft parked on the strip and the aircraft overran the edge of the strip.

74-012 7 31

74/17 ACC MA 1/02/1974 CMK NGAMATAPOURI

Unable to position the loader bucket directly over the hopper mouth the driver backed his vehicle away to make another approach. the pilot, believing the aircraft had been loaded and that the loader was clear, applied power to taxi and the aircraft fin struck the loader bucket.

74-060 7 32


74/21 ACC MA 12/02/1974 CMK WHANGAMOMONA

A precautionary landing was being made on a farm strip due to failing light but the brakes were ineffective in slowing the aircraft on wet grass and during an attempted groundloop the aircraft slid over a 20 ft bank.

74-074 7 33

74/38 ACC MA 24/03/1974 BVB PUKEKOHE EAST

During a low level run made over an airstrip to influence grazing cattle to move away from the landing area, the aircraft struck one of the animals and afterwards collided with a building, an outer wing panel being dislodged. it then dived into the ground.

74-034 7 34

74/45 ACC MA 31/03/1974 DBZ MAPIU On short finals for a hillside airstrip landing, low morning sun restricted the pilot's view ahead. the aircraft touched down well into the strip and could not be stopped before it collided with a loading bin

74-039 7 35

74/66 ACC MA 20/05/1974 BXS WAIOTAPU During a familiarisation flight over an area to be sown the port wing of the aircraft collided with and severed 33,000 volt high tension cables. although damaged the aircraft remained controllable and was flown back to the strip.

74-064 7 36


74/68 ACC MA 22/05/1974 BXQ NR KAITAIA AD

Deteriorating weather halted topdressing operations and pilot attempted to return to base. landings were made on several intermediate airstrips because of the weather. when he was landing on 3rd such airstrip cattle ran out of scrub and pilot landed beyond them. there was no effective braking on flat waterlogged strip and aircraft skidded into a fence.

74-068 7 37

74/78 ACC MA 28/06/1974 DJD TARINGAMOTU

The port wheel struck the lip of the strip during an approach and as a result the leg folded rearward during the roll.

74-076 7 38

74/112 ACC MA 1/10/1974 CZC NR RUATORIA

The pilot, comparatively inexperienced in agricultural flying operations, misjudged the turning radius of his aircraft which, during a steep turn, collided with a hillside

74-107 7 39

74/142 ACC MA 17/12/1974 DSL MAUNGATI While the pilot was flushing out the spray gear and flying above a gorse fence the aircraft collided with power lines strung in a 34-chain span across a broad valley. he had not been informed of their presence nor had he previously noticed them.

74-139 7 40

74/144 ACC MA 20/12/1974 BWV NR PONGOROA

The aircraft undershot on approach and the wheels struck a bank on the threshold. the wheels separated and the aircraft came to rest on the strip.

74-141 7 41


75/11 ACC MA 11/01/1975 BHJ PONGAROA During an overshoot to avoid the animal, the aircraft struck a lamb which had run across the landing path.

75-007 7 42

75/17 ACC MA 27/01/1975 BIT RAETIHI Owing to a low sun directly ahead the pilot chose to land on the reciprocal vector in calm conditions. trees in line with the approach path reduced the effective strip length and this, coupled with poor braking effect on wet grass, allowed insufficient ground run to bring the aircraft to rest normally.

75-014 7 43

75/122 ACC MA 16/11/1975 CYN MOKAUITI Several 'clean-up' sowing runs were made up the lee side of a hill. on the third run the aircraft was unable to clear the top of the hill and while it was turning away from it the outer wing panel collided with a tree. the aircraft remained controllable and was flown back to the strip.

75-118 7 44

76/57 ACC MA 14/04/1976 DJY MATAIKONA

During the takeoff run the pilot observed sheep crossing the strip. he closed the throttle and turned the aircraft towards rising ground on the right side of the strip but as the nose wheel ran up the slope the tail was brought into contact with the ground.

76-051 7 45


76/64 ACC MA 14/05/1976 DMT TE AKAU After landing on the strip to commence operations the aircraft was travelling too fast when an attempt was made to turn around at the end of the strip. control was lost on frosty ground and the aircraft slid into a fence.

76-065 7 46

76/71 ACC MA 28/05/1976 CWQ POLLOK When the aircraft was landing on a short steeply sloping strip prior to commencement of operations, a strong downdraught was encountered on short finals. the aircraft landed heavily on the lip of the strip and an undercarriage leg collapsed.

76-067 7 47

76/89 ACC MA 2/08/1976 BXQ WAINUI While turning on to a sowing run the pilot mistook a set of power wires for another he had crossed previously. on descending to sow the aircraft collided with wires, a portion of the fin and rudder separated, but the aircraft landed without further incident.

76-088 7 48

76/108 ACC MA 17/09/1976 CBG RUAPUKE During a landing on a greasy strip with a cross/tail wind, a gust caused loss of directional control. the aircraft veered off the strip and the nose leg ran over a 2-3 ft bank and collapsed.

76-104 7 49


77/30 ACC MA 14/02/1977 CLI ARIA Just prior to touchdown on a shaded strip the pilot found the area unsuitable while avoiding the area he failed to maintain his landing direction and the aircraft's right outer wing section struck the loading vehicle.

77-029 7 50

77/67 ACC MA 29/04/1977 CDZ KAIPARA FLTS AD

On returning to base for the fourth time during the day's operations, the pilot noticed that all sheep were gathered on one side of the strip. as the aircraft touched down one sheep ran clear of the others and was struck by the left main wheel of the aircraft.

77-070 7 51

77/72 ACC MA 24/05/1977 CZB NR WAIKANAE

The pilot was distracted by talking to the farmer during loading. he commenced taxiing before loading was complete and the elevator struck the loading vehicle.

77-075 7 52

77/144 ACC MA 22/12/1977 DBG NR SEDDON

After touchdown braking proved to be ineffective on the wet grass surface and the aircraft slewed sideways over a bank beyond the loading bay.

77-150 7 53


77/145 ACC MA 23/12/1977 DUJ MAURICEVILLE

The pilot who had been operating from the airstrip during the day, following his usual landing approach pattern, failing to realise that the tailwind component had increased to some 20 knots. owing to previous heavy rain, braking action was ineffective on the wet grass surface and the aircraft overran the end of the strip, sustaining substantial damage.

77-153 7 54

78/39 ACC MA 7/03/1978 CZA TAIHAPE During an early morning flight the aircraft collided with two paradise ducks, one of which penetrated the front windscreen.

78-044 7 55

78/73 ACC MA 14/05/1978 DZM WESTMERE When the aircraft was landing on a wet airstrip, the brakes locked as the pilot applied light braking and the aircraft slid into a fence.

78-072 7 56

78/93 ACC MA 20/07/1978 CWQ PAUA The wind increased considerably while the aircraft was away spraying and a quartering tail wind was blowing when it landed back on the wet and greasy strip. towards the later part of the landing roll the pilot lost directional control of the aircraft and it commenced to groundloop. one wing struck a fence.

78-094 7 57


78/106 ACC MA 21/08/1978 DDA NR OWAKA During a grass seeding operation the aircraft struck a tree at the end of a sowing run. the complete left wing separated from the aircraft which then rolled and dived into the ground. the aircraft burnt out.

78-105 7 58

78/108 ACC MA 23/08/1978 EGU MAUNGATAPERE

The aircraft was landed in a gusty tailwind. the airspeed was higher than normal and the aircraft touched down well beyond the threshold of the airstrip. the braking action on the wet grass was poor and the aircraft could not be stopped before it collided head-on with the loading vehicle which the passenger was planning to drive to another area.

78-107 7 59

78/142 ACC MA 1/11/1978 CAY HIKURANGI The aircraft was landing with a tailwind and touched down well up the strip. as the pilot considered the aircraft could not be stopped in the remaining distance, he attempted to ground loop the aircraft on the loading area, but the aircraft's right wing collided with a bank.

78-140 7 60


78/144 ACC MA 8/11/1978 BHL GLADSMUIR STN

In course of topdressing operation company pilot agreed to loader driver's request to complete days sowing. loader driver a commercial pilot with a type rating for aircraft but unauthorised by company to fly aircraft. during a turn between sowing runs, across face of sloping paddock pilot lost control of aircraft which struck ground heavily and destroyed on impact.

78-143 7 61

78/147 ACC MA 17/11/1978 DZL KAKATAHI Aircraft was one of two engaged in a topdressing operation. pilot of second aircraft was returning to sowing area when he saw other aircraft heading away into a blind valley. shortly afterwards it attempted a steep climbing turn and disappeared from view. when pilot of second aircraft arrived over the area the wreckage was on fire.

78-145 7 62

79/19 ACC MA 30/01/1979 EHX KIRIKAU While sowing superphosphate along a road boundary the aircraft collided with an electric power conductor. the wire broke and whipped across the windscreen. the conductor was suspended some 250 feet agl.

79-026 7 63


79/24 ACC MA 4/02/1979 CZA SILVERHOPE

The pilot decided to make an unscheduled landing on a company airstrip due to unsuitable weather during a ferry flight. the surface of the strip was wet and the pilot lost directional control of the aircraft during landing. he was unable to prevent the aircraft from colliding with one of a line of concrete power poles running parallel to the strip.

79-024 7 64

79/59 ACC MA 29/03/1979 BXQ WAIOTAHI A tailwind necessitated taxiing to the far end of the strip and taking off back towards the loading area. starting work after a frustrating refuel the pilot lost his concentration and attempted to takeoff downwind. when he realised his mistake the aircraft could not be stopped in time and it ran down a bank into some cattle yards.

79-057 7 65

79/61 ACC MA 9/04/1979 CAY NR PAPARATA

The aircraft struck a fence while taking off on an agricultural sortie and the resultant damage caused it to roll into an inverted attitude and dive into the ground.

79-060 7 66

79/79 ACC MA 27/05/1979 DUI MAHOENUI A very low approach to a ridge airstrip was made because of low stratus cloud which covered the top end of the strip. the pilot landed parallel to the edge of the strip but was unable to follow the curved strip and ran off the side.

79-077 7 67


79/85 ACC MA 13/06/1979 CPN HOROHORO

Whilst on a topdressing sortie the aircraft struck a transmission power line and crashed inverted into pokaitu stream.

79-083 7 68

79/119 ACC MA 6/10/1979 CZA NR EKETAHUNA

The pilot was aware of the power lines across the area being topdressed. however the aircraft struck and severed the conductors when the pilot became preoccupied with sowing around some trees

79-123 7 69

79/145 ACC MA 4/12/1979 CRX MANGATARERE VLY

While making a procedure turn the aircraft assumed a steep nose down attitude and impacted heavily on the terrain. the pilot was fatally injured and the aircraft was destroyed by impact forces and fire.

79-143 7 70

80/10 ACC MA 16/01/1980 EGI STIRLING After touchdown in crosswind conditions on a wet and greasy strip the pilot lost directional control of the aircraft which slid sideways into a gully.

80-010 7 71

80/12 ACC MA 26/01/1980 EMC NR TAIHAPE

Pilot took property owner's daughter on survey flight to point out boundary of area to be topdressed. after flight pilot told her to leave aircraft by stepping over trailing edge of wing. however after leaving seat and climbing onto wing she hesitated briefly then jumped over leading edge of wing walked into path of rotating propeller: received serious injuries and died later

80-012 7 72


80/24 ACC MA 1/02/1980 CPY NR TEMUKA

Aircraft collided with a tree while in a turn to the left. fuselage structure forward of cockpit was demolished and seriously injured pilot was freed from aircraft with assistance of local emergency services. no fire. accident survivable only because pilot was wearing a full safety harness and crash helmet.

80-022 7 73

80/53 ACC MA 8/04/1980 CLO PAPONGA Due to sun glare the aircraft landed some 30 degrees off the airstrip heading and collided with a bank.

80-051 7 74

80/80 ACC MA 3/07/1980 CMM BANKS PENINSULA

The aircraft collided with the loading vehicle as the pilot commenced taxiing.

80-079 7 75

80/85 ACC MA 17/07/1980 CRP NR KAIKOHE

During a ferry flight from kaitaia to whangarei the aircraft made several low runs over the pilot's parents' property. at the completion of a turn made after a run up the side of a hill the aircraft disappeared from sight behind a ridge. a short while later the occupants of a passing helicopter noticed the aircraft wreckage in steep bush covered terrain.

80-082 7 76

80/109 ACC MA 8/10/1980 EMV MORRINSVILLE

After touching down the pilot was unable to prevent the aircraft overrunning the runway.

80-107 7 77


81/3 ACC MA 9/01/1981 DJE NR MANGAMAHU

Aircraft operating from a 450 m grass airstrip on a topdressing operation in calm conditions. aircraft touched down on the wet grass but was travelling too fast for the calm conditions and poor braking action. as a result it skidded into a superphosphate bin located at the end of the airstrip.

81-003 7 78

81/6 ACC MA 14/01/1981 EGS TINUI During the takeoff roll the aircraft struck a sheep but became airborne safely with a damaged stabiliser. after a low pass during which the damage was described by the loader driver the pilot landed the aircraft normally.

81-006 7 79

81/21 ACC MA 17/02/1981 DLV WHANGAEHU RVR

During a right turn, to position the aircraft near the loading vehicle after landing, the pilot misjudged the aircraft's distance from a fence strainer post. the outer portion of the left wing was damaged in the collision.

81-019 7 80

81/30 ACC MA 1/03/1981 DUI OTANGIWAI

The aircraft collided with a high tension power conductor during a topdressing sortie. the collision caused the aircraft to dive into the ground out of control. the pilot received fatal injuries in the accident.

81-028 7 81


81/59 ACC MA 29/05/1981 CBE NR RAGLAN The aircraft touched down too far along the wet airstrip and could not be stopped before it passed its normal loading position. while the pilot was turning it to avoid the loading vehicle, the aircraft passed over a small retaining wall which tore off the hopper box and tipped the aircraft onto its right wing tip.

81-058 7 82

81/90 ACC MA 4/11/1981 DHY NR CAMBRIDGE

While on a survey flight the pilot dived the aircraft to attract the attention of another farmer client who was cultivating a paddock on the valley floor. during the descent the aircraft struck 3 copper power conductors which the pilot had not sighted against the brown earth background.

81-119 7 83

82/45 ACC MA 23/04/1982 EMA POOLBURN While landing, still banked to the right, the aircraft's right wing hit a protruding rock off the side of the strip.

82-043 7 84

82/59 ACC MA 18/06/1982 EMR ONEWHERO

After bringing the aircraft to a stop the pilot decided to taxi around to refuel. the aircraft's tail struck the loader vehicle which had moved in without his being aware of it.

82-051 7 85


82/63 ACC MA 28/06/1982 BIO PUKEATUA At the end of a sowing run the aircraft entered a climb and rolled into a reversal turn to the right. part way through the turn the aircraft was observed to descend steeply and it struck a power pole before impacting heavily in an adjacent paddock. the pilot was seriously in the accident and died in hospital the next day.

82-064 7 86

82/116 ACC MA 8/12/1982 BPZ WHITEMANS VLLY

While the aircraft was turning in a valley between sowing runs it struck a ridge and a fence then cartwheeled and dived into the ground. the pilot was fatally injured in the accident.

82-115 7 87

83/24 ACC MA 28/02/1983 CLI NR MANGAMINGI

The pilot initiated a climb from the end of a sowing run and then commenced a turn to the right. during this manoeuvre the aircraft entered a steep dive and collided with the terrain .

83-025 7 88

83/54 ACC MA 2/06/1983 EGH NR RAWENE

While taxiing from the loading bin the aircraft commenced sliding sideways down the slippery clay surface of the airstrip. the pilot shut down the engine and the aircraft slid down a bank and came to rest in contact with a fence.

83-054 7 89

84/35 ACC MA 20/03/1984 EMI NR WAIMATE AD

The aircraft departed in low ceiling conditions and collided with the terrain 2km from the aerodrome.

84-035 7 90


84/36 ACC MA 21/03/1984 JAB WAIPUKURAU AD

During a cross-wind takeoff the pilot allowed the left wing to drop and collide with the runway as the aircraft lifted off. the ensuing circuit and landing was completed uneventfully.

84-037 7 91

84/41 ACC MA 9/04/1984 DUG PURUA The pilot misjudged his approach and the aircraft touched down, too far up the strip at an excessive speed. in an attempt to retrieve the situation the pilot applied full power but the aircraft became airborne too late and collided with the terrain.

84-042 7 92

84/84 ACC MA 16/08/1984 DZF HILLEND During takeoff the left wing of the aircraft struck several cattle which had wandered onto the airstrip but were not visible from the takeoff point. the aircraft remained controllable and was flown on to balclutha.

84-085 7 93

84/88 ACC MA 14/09/1984 EUE TE MIRO While positioning for a spray run the aircraft was rolled inverted by turbulence. the pilot recovered the aircraft to a level attitude but was unable to prevent it squashing into bush on the valley floor

84-091 7 94


84/100 ACC MA 27/10/1984 DJF NR HOKITIKA AD

During an attempted closely sequenced descent of four parachutists the first jumpers reserve chute was inadvertently released. he was pulled into the tailplane and the aircraft went out of control. the parachutists landed safely but the pilot who was not wearing a parachute was killed in the ground impact.

84-106 7 95

86/49 ACC MA 10/06/1986 DSL NR KAIKOHE

After loading the aircraft by hand, the pilot walked to the edge of the strip to clean his hands. the aircraft commenced to move across the loading area and could not be stopped. it rolled off the side of the strip and down a steep bank. the reason for the park brake's release was not determined.

86-050 7 96

87/78 ACC MA 17/08/1987 DLV NR MASTERTON

During a turn at the end of a sowing run the left wing tip collided with a tree.

87-084 7 97

87/101 ACC MA 5/11/1987 CKA OTOROHANGA

The aircraft's tailplane struck the loader vehicle while the pilot was lining the aircraft up for takeoff.

87-110 7 98

87/102 ACC MA 16/11/1987 DMT TIRAU During a spray run, the tip of the aircraft's spray boom caught in an electric fence feeder wire. several aircraft components received substantial damage when the wire separated.

87-111 7 99


87/115 ACC MA 15/12/1987 CWQ NR WAIRAKEI

The trainee pilot was sowing over a small prominent hill. on the last run he made a steep turn to avoid the hill but the lower wing struck the ground. the aircraft cartwheeled and rolled down the hill.

87-125 7 100

88/50 ACC MA 20/07/1988 CMK WAITANGIRUA

The pilot lost directional control of the aircraft after landing downwind on a wet, uphill strip. it slid off the strip into an adjacent building.

88-051 7 101

88/54 ACC MA 2/08/1988 CLO TE AKAU During a spray run up a hillside in misty rain, the right wingtip struck a fencepost dislodging the aileron. while rolling out of control, the aircraft passed through a fence which arrested its forward speed, allowing it to slide down a hill to a halt.

88-055 7 102

88/75 ACC MA 27/10/1988 EGW URITI VALLEY

The aircraft struck a wire which ran from a hill top tv aerial to a house in a nearby valley.

88-077 7 103

89/41 ACC MA 14/04/1989 CTS MOTEA The air was calm on the approach but a strong gust was encountered as the aircraft crossed the threshold. the pilot attempted a go-around immediately but the aircraft's angle of climb was insufficient for it to clear a row of trees. after the resulting collision the aircraft remained flyable but the limited control available dictated an immediate forced landing.

89-044 7 104


89/80 ACC MA 6/10/1989 DIL ALBURY As the loader backed away from the loaded aircraft it stalled. the pilot failed to notice the vehicle was not clear of his aircraft and commenced takeoff, causing the tailplane to strike the vehicle.

89-082 7 105

90/101 ACC MA 7/08/1990 BII PEEL FOREST

When the aircraft 'fish tailed' during the landing roll the pilot attempted a go around. the left wing collided with a gorse bush yawing the aircraft and causing it to descend down the side of a ridge into thick gorse.

90-075 7 106

91/145 ACC MA 19/04/1991 BDS nr Ruatahuna

Landing, hit loader, outer wing damage

7 107

91/790 ACC MA 20/10/1991 EHX 7 W Turangi

Collided with hill 7 108

92/2055 INC MA 12/07/1992 BII EYREWELL A/C SPRAYING POISON. HIT SOME WIRES. A/C ON GORUND TAXYING UP TO HOUSE. J SCOTT DAGNAM FARM DONCASTER RD OXFORD

7 109

92/3812 INC MA 2/11/1992 BXZ TE HOE ON APPROACH DOG OBSERVED RUNNING DOWN MIDDLE OF STRIP. FULL POWER APPLIED AND A TUNE TO LEFT INITATED. GUSTY CONDITION W/TIP PASSED THRU WIRE OF FENCE

7 110

93/1420 ACC MA 18/03/1993 EMT Kina Rd Hit loader vehicle, damage to tailplane

7 111

93/2836 ACC MA 24/06/1993 BHJ 5 SW Blenheim

Wet slippery strip, hit vehicle 7 112

93/4359 ACC CR 28/09/1993 BHU 1 SE Tauwhare

Collided with terrain, cause unknown

93-012 7 113


93/5997 INC MI 9/12/1993 CML HINUERA DURING SHALLOW TURN CLIPPED A STRAINER POST WITH PORT OUTER WING TIP. DAMAGING LOWER OUTER AILERON SKIN.

7 114

94/744 ACC MI 1/03/1994 CMZ nr Hastings Landing, overran airstrip 7 115

94/2369 ACC MI 6/05/1994 BHK Stratford Ad

On landing, hit hedge 7 116

94/3123 ACC MI 27/07/1994 CBA Waihi Bch After landing, hit utility vehicle at end of strip

7 117

94/3485 ACC MI 25/08/1994 DHE Otutira Collision with loader 7 118

95/262 ACC CR 9/02/1995 BIF NIHANGA RD, MANGAKIN

WIRE STRIKE CAUSING A CRASH 7 119

95/560 ACC CR 5/03/1995 EGO NGAPURU WHILE LANDING AT A FARM AIRSTRIP THE FU24-950 WAS CAUGHT BY A WIND GUST FROM THE REAR CAUSING THE PILOT TO LOOSE CONTROL.

7 120

95/2448 ACC CR 30/08/1995 CMY 454 RANGANUI BLOCK R

An aircraft was landing empty, when it was caught by gust of cross wind and blown off side of the strip down a bank.

7 121

96/11 ACC CR 2/01/1996 DZM Masterton Narrow ridge top airstrip, Waimanu Farm. Landing, reasonably strong cross wind which swept up bank under starboard wing. Rolled acft almost onto port wing. Broke dihedral 10 inches outside attachment bracket, broke wing almost in half, broke rear attachme nt point.

7 122

96/522 ACC CR 29/02/1996 EGM 4 S Piopio A top dressing aircraft nose impacted then cart wheeled.

7 123


96/831 ACC MA 20/03/1996 EMX Otaua Aircraft landed well into the strip and could not stop using normal braking. Attempted ground loop and shut engine down. Aircraft came to rest with tail down hill.

7 124

96/1640 INC MA 5/04/1996 EGQ RAI VALLEY Acft rolled off strip whilst unattended -substantial damage. Parking brake not properly applied.

7 125

96/1790 INC MI 7/07/1996 JAL HAMILTON ZK-JAL 1935/1940 overdue action commenced 15 mins after aircraft should have reported vacating the zone. Contact established 2 mins later by another aircraft and AA supervisor advised.�Cause - lapse of memory by experienced pilot.

7 126

96/2110 ACC MA 4/08/1996 JAA WHAREHINE

On take off acft started slewing to left out of pilots control. Reduced power but acft continued through down hill fence.

7 127

96/2236 ACC CR 23/08/1996 EGQ 10 NM SW Motueka

While on a routine sowing run, 16 km south-west of Motueka, the left wing-tip of the aircraft struck a lone pine tree damaging the left aileron. Control difficulties resulted and the aircraft collided with the face of a steep ridge. The aircraft was des troyed and the pilot lost his life in the accident.

96-016 7 128

97/462 ACC MA 14/02/1997 DDW 7 S Clinton Coming in to on land top-dressing strip. Aircraft landed off centre line and hit an earth bank.

7 129


97/3164 ACC CR 20/10/1997 DZC Neudorf Returning to the airstrip after spreading a load the engine stopped due to the aircraft running out of fuel. When the engine stopped I landed straight ahead on a flat paddock. There was a young bull in the paddock and I was unable to avoid him. The fieldw as quite short and the longest distance I could get to stop in was the same path the bull took. I collided with the animal in a semi ground loop and the aircraft stopped. Damaged to the propeller was sustained.

7 130

97/3767 ACC MA 12/12/1997 CQB Henley On take off in gusty conditions the wing dropped and contacted the ground. As the aircraft was airborne the flight continued uneventfully to Dunedin aerodrome

7 131

98/115 ACC MA 27/01/1998 JAB 14 SE Waipukurau

The pilot elected to land on his home strip with a 10 knot tailwind. On short final the aircraft lost height; the starboard undercarriage struck the end of the strip and was torn off.. The pilot elected to go around and land on a more suitable area (paddo ck) about two miles to the east. During the landing the starboard flap was further damaged.

7 132


98/2669 ACC MA 17/09/1998 BOG Lumsden Sheep ran across landing strip during landing and struck aircraft. tore spreader off and damaged flaps and holed fuselage. Stock often present at this Lumsden base strip but normally cleared by low pass

7 133

98/3403 DEF MI 4/11/1998 EMG GORE AERODROME

Aircraft ZK-EMG (Fletcher) was parked in front of the fuel pump on Gore airfield unattended. A Cessna-206 came over and parked behind ZK-EMG with its motor still running. While its pilot attempted to move ZK-EMG from the re-fueling area, the pilot accid entally knocked off the park brake of the Cessna --- thus resulting in the aircraft to move forward and its propeller to chop into the tail section of ZK-EMG.

7 134

99/1313 ACC MA 8/05/1999 EUH STRATFORD This aircraft was carrying out a landing at a top dressing strip, when the pilot notice piles of road metal/seal near the threshold. The pilot was unable to to avoid the piles of metal and hit them causing damage to right hand wing, flap, and undercarria ge.

7 135


00/159 ACC MA 25/01/2000 JAA South Kaipara

After the aeroplane had been loaded, the pilot began taxiing for take-off. He had moved about one metre when the left tip of the tailplane struck the loading vehicle, which had moved in towards the aeroplane again unbeknown to the pilot.

7 136

00/615 ACC MI 27/02/2000 EGI Owaka During loading, the aircraft was struck on the left side by the loading vehicle.

7 137

00/532 ACC MA 2/03/2000 EUF Motunau The aircraft was sowing lime on a property when it collided with wires in a gully. The impact was taken on the nosewheel, which collapsed back against the fuselage. The pilot flew to a suitable field, shut down the engine and made a forced landing.

7 138

00/617 ACC MA 11/03/2000 EUH Urenui The loading vehicle was reversing away from the aeroplane after loading, and collided with the outer leading edge of the tailplane.

7 139

00/945 ACC MA 26/03/2000 EGU Stratford On takeoff the pilot experienced sunstrike the aircraft hit a strainer post near the end of the strip causing minor damage to the tail cone area and underneath the rear fuselage.

7 140


00/4522 ACC MA 7/11/2000 EUC Napier An increased tail wind on landing caused the Fletcher to over run the airstrip and collide with a fence post. The aircraft sustained damage to the propeller, left fuel tank and left outer wing panel.

7 141

00/4421 ACC MA 10/12/2000 BOG Five Rivers The aircraft failed to stop before the end of the paddock & skidded sideways into an embankment, which caused the port main leg to collapse, and the propeller to contact the ground.

7 142

01/2307 ACC MI 14/01/2001 EUC Patoka While starting a take-off roll, the aircraft's right-hand aileron contacted the ground. Pilot aborted the take-off and the damaged aileron was replaced and aircraft returned to Napier for repairs to be completed.

7 143

01/191 ACC MA 21/01/2001 CML Honikiwi ZK-CML landed into wind on a downhill slope airstrip. However the grass was slightly wet and it skidded off the end of the airstrip and over a bank.

7 144


01/755 ACC MA 7/03/2001 DHE Puketutu The tailwind increased when the aircraft was about 5' above the ground. The pilot elected to continue in the belief that he would be able to stop in time. However, dew and lush grass caused poor braking performance and the aircraft slid about 180 m until the left wing hit a post which turned it 90 degrees and sent it down a small gully. It was substantially damaged.

7 145

01/3117 INC MA 5/09/2001 CQB Taieri Mouth

After completing a job, pilot uplifted farmer to fly round and survey another block to be topdressed. Pilot's intention was to take the farmer and no fertiliser however the loader driver unexpectedly brought the loader to the aircraft, unobserved by the p ilot. When power was applied, the aircraft moved forward and the tailplane came into contact with the loader's cab, causing damage to the RH stabiliser tip, fuselage skin and one stringer.

Rear skin & Stringer

243034L 7 7 146


01/4022 ACC MA 19/11/2001 CMK Tokoroa During spray ops, the pilot realised that he had taken longer than anticipated and decided to return to the strip for fuel. On the way back the fuel pressure gauge flickered, so he decided on a precautionary landing on a forestry road. During the landin g the right wing struck a tree stump causing the aircraft to swing off the road and into 4-foot high pine trees.��The aeroplane was substantially damaged but the pilot was uninjured.

211 7 147

01/3886 ACC MA 20/11/2001 UTE Kohukohu The aircraft was approximately a third of the way down the airstrip on its takeoff run when the pilot became aware that the control lock was fitted, but he was unable to remove the device. The rough surface of the airstrip coupled with sufficient nose do wn force to the nose resulted in collapse of the nose gear, and substantial damage to the aircraft.

7 148

02/2324 INC MI 20/02/2002 DZG Wairamarama

During the takeoff, from a strip, some sheep ran across the front of the aircraft. In avoiding one sheep the left wing hit another.

7 149


02/1428 INC MI 16/04/2002 JNX Ngakuru During the takeoff roll the nose wheel entered a small depression that compressed the oleo strut and caused a prop strike.

7 150

02/2050 ACC MA 18/04/2002 DZM Mauriceville

The aircraft landed on the farm strip a little right of the centre and the propeller and nose wheel hit a bank, which resulted in substantial damage.

7 151

02/2248 ACC CR 24/07/2002 EOE Thames The Walter Fletcher was spraying a paddock when the right wing struck an outstanding branch, the aircraft then collided with a row of trees, rolled and impacted the ground inverted. The pilot did not survive the accident.

7 152

02/3469 ACC CR 30/11/2002 EMO Lindis Valley

The aircraft was witnessed by the loader driver to be in a steep left turn (possibly after conducting a go around from the landing approach). It then collided with rocks on high ground and rolled inverted and slid down a hill seriously injuring the pilot.

7 153

03/463 INC MI 8/01/2003 EMN Tairei The aircraft was left running and unattended while the pilot spoke to his engineer. Blustery conditions caused the brakes to let go and before the pilot could intervene it moved forward and hit the hangar. Damage was done to the propeller and the starboar d wing leading edge.

7 154


03/741 INC MA 14/02/2003 CKA Pomerangi The tailskid area of the rear fuselage made contact with the ground while landing on a steep airstrip.

Rear Bulkhead

243011 and 243239

7 155

03/843 ACC MA 24/03/2003 DUJ Eketahuna The aircraft was engaged in a sowing run when it hit some high tension lines 200' AGL. The pilot was able to fly 25nm with limited aileron control and land safely at Masterton Aerodrome.

7 156

03/976 ACC CR 4/04/2003 LTF 10 NE Stratford

The aircraft was engaged in its last sortie of the day before returning to Stratford. It was reported overdue and the wreckage found in the early hours of the morning. Both occupants were dead and the aircraft was destroyed.

7 157

03/1180 INC MI 15/04/2003 DJE Nelson The aircraft was taxiing on the western grass when the left wing struck a sign at holding point 'Whiskey' causing damage to the wing.

7 158

03/2941 INC MI 28/05/2003 BDS Opotiki Operator reports that during an ag-operation the fertiliser loader bucket struck the side of the fertiliser concrete bin. Broken pieces of concrete went into the aircraft hopper with the fertiliser. While spreading, a piece of concrete impaled itself in to the wall of a house on the property being sown. No injuries occurred.

7 159


03/2679 ACC CR 20/09/2003 BDS Matawai HSE-It was reported that the aircraft encountered low cloud and poor visibility during the flight so the pilot decided to turn back. It was during this turn that a high sink rate was encountered which caused the aircraft to collide with a hillside. Both o ccupants were injured.

7 160

03/2852 ACC MI 29/09/2003 EMX Ngakuru The Fletcher was landing when a crosswind gust, from the left, caused the aircraft to weathercock towards the boundary. The pilot applied full right rudder but the aircraft continued to slide and the underside of left wing to scraped over 4 fence posts c ausing some wing damage to the aircraft..

241339L & 241538L

278 7 161

03/3286 ACC MI 31/10/2003 EGW Kirikopuni The pilot landed the aircraft with a tailwind well into the strip the long grass surface of which was affected by dew. The pilot ran the aircraft off the side of the strip to avoid the loading truck causing damage to the tailplane.

7 162

04/2195 INC MI 3/06/2004 JAA Paengaroa The pilot flew the aircraft down a gully at a lower level than normal to minimise the drift of the fertiliser being sown. The aircraft struck an electric fence wire, strung between the tops of adjacent ridges. The wire broke limiting the damage to superf icial scratching of the wing.

7 163


04/3919 INC MI 28/10/2004 EGW Whangarei 5E36 It was reported that ZK-FVD had just landed on runway 06 at Whangarei and had rolled past the appron exit to the turning bay to turn around and backtrack. During this time a ZK-EGW landed on run way 06 while FVD was still on the runway.

7 164

04/4277 DEF MI 1/11/2004 CRY Waikeke Super Air reported that the aircrafts elevator was clipped by a loading vehicle as it was taxing off.

7 165

05/138 ACC MI 24/01/2005 CLO Heriot (West Otago)

It was reported that the aircraft veered off the runway during landing and crashed into some trees.

7 166

05/665 INC MI 28/01/2005 EMN Owaka It was reported that the aircraft initiated the take off before the loader has cleared the area. This resulted in the aircraft's elevator hitting the loader, which caused it to be out of alignment and damaged the port rear fuselage about the elevator hing e point.

7 167

05/963 INC MI 9/02/2005 EGS Dannevirke The pilot reported that whilst taxing on a farm airstrip the distance to a fence line was misjudged and collided with a strainer post impacting the right aileron and outer panel

7 168


05/385 INC MI 14/02/2005 EGP Owhata The pilot landed the aircraft too far into the paddock with a quatering tailwind . Wet grass also decreased braking effectiveness and the aircraft overran the runway through a fence and came to rest some 40 metres beyond the landing area.

7 169

05/644 INC MI 16/02/2005 CRF Taupo Taupo Unicom reported that the Fletcher flew through the parachute drop zone after being advised by a parachute drop pilot not to join overhead.

7 170

05/689 ACC MI 5/03/2005 JNX Rotorua The aircraft was approaching the loading area just after landing when the pilot attempted to slow the aircraft down by selecting beta but there was no response. Full reverse was then applied and the aircraft stopped successfully before reversing itself d own a slope.

7 171


05/1353 ACC MA 5/04/2005 DHD Wanstead Airstrip

While landing on a short airstrip possible wind shear was experienced. The aircraft sank rapidly and full power was applied which had no effect. The aircraft hit the ground heavily resulting in substantial damage. �The wind at the time was near maximum c ross wind and swinging.�The chief pilot spoke to the pilot and made him aware of the risks in operating in marginal conditions.

7 172

05/1214 INC MI 7/04/2005 DZG Hamilton The Fletcher Fu 24-950 was taking off and touched the tail skid on the airstrip

7 173

05/2339 ACC MA 25/07/2005 EGV Manawahe RCCNZ reported that during the landing roll the aircraft went off the edge of the private airstrip during this time the propeller and tail were damaged.

7 174

05/4387 INC MI 18/10/2005 EGW Te Kuiti Super Air reported that the aircraft required a tighter turn than normal to miss a large hole which had developed in front of the picket line. Subsequently the right hand wing tip caught the fuel pump and damaged the fibre glass tip. No damage was done to the pump.

7 175

05/4386 INC MI 17/12/2005 EMW Rotorua Whilst landing at Thorpe's Airstrip in a rain shower a gust caused the right wing tip to touch the ground before the pilot could arrest its descent.

7 176


06/464 ACC MI 17/02/2006 EGS Pahiatua The aircraft caught the loader bucket when the take off run was commenced. Substantial damage was sustained to the rear bulkhead, elevator attachments, rear fuselage and elevator.

7 177

06/2392 INC MI 7/05/2006 EGW Waikato It was reported that the aircraft went through 2 strands of lowered electric fence wire that had not been removed from the airstrip.

7 178

06/2393 INC MI 9/05/2006 EGV Ohiwa Harbour

It was reported that the aircraft's prop struck the ground during manoeuvring on the loading area while lining up for a load of fertiliser.

7 179

06/4204 INC MI 31/10/2006 CKA New Plymouth

The aircraft taxied into a soft depression on the airstrip loading area after refuelling causing minor damage to the propeller. The cause was attributed to a rough, soft and undulating airstrip loading area.

7 180

06/4206 INC MA 1/11/2006 CRY Hukrenui It was reported that there was a sudden gust of wind which pushed the aircraft off the strip during the landing. The left hand aileron hit the fence causing it to skid to the right

7 181


07/1585 INC MI 7/04/2007 EUD ROTORUA The pilot had dropped the fuel card on floor of cockpit. The park brake was applied, and propellor condition lever was taken through to full feather, the pilot had his head down below the seat. While trying to locate the card, the pilot knocked the pr opellor condition lever back to flight idle, causing aircraft to taxi forward 5 metres in an arc due to one wheel brake not holding. The right hand wing leading edge contacted a metal ladder causing minor damage.

7 182

07/1191 ACC MA 16/04/2007 JNX Te Poi The pilot was using the airstrip for the first time. On landing he misjudged the line of the airstrip and landed in a depression towards the side of the airstrip. This resulted in the spreader contacting the ground and being torn off causing damage to th e fuselage, left flap and elevator.

7 183

07/2254 DEF MI 12/06/2007 EGV New Zealand

Super Air reported that the aircraft hit a sheep during the takeoff.

7 184

07/2255 INC MI 20/06/2007 EGW New Zealand

Super Air reported that the aircraft expereinced a heavy landing which dislodged the spreader attachment.

7 185

08/836 INC MI 10/01/2008 JAA Papamoa Super Aid Ltd reported pilot pulls away from loader truck too quickly striking elevator on truck guard.

7 186


08/834 INC MI 21/02/2008 JAA Te Puke Super Aid Ltd reported pilot taxiied into hole off side of airstrip.

7 187

08/2101 INC MI 24/04/2008 DZO Kairangi Loader driver drove into aircraft RH Flap in "sun-strike" while loading aircraft with fertilizer.

241600R RL488 7 188

71/51 ACC MA 10/05/1971 DEQ CAPE RUNAWAY

A forced landing became necessary following what the pilot believed to be a fall off in engine power. the integral actuating pin of one propeller blade was found fatigued and although it could not be established that this component failed in flight, the evidence suggests that it did. reports of similar in-flight failures overseas support this conclusion.

71-048 8 1

73/58 ACC MA 2/04/1973 CMY WAOTU One blade of the mccauley d2a 34c58/5-90at-4 propeller failed at the root end during takeoff. unbalance then caused the crankshaft to fail behind the propeller attachment flange.

73-073 8 2

94/1428 DEF MA 5/04/1994 EGU PALMERSTON NORTH

PROPELLER BLADE PITCH CHANGE K

E49192 8 3

94/3486 DEF MA 22/08/1994 CML HAMILTON Pilot noted engine vibration and airspeed washing off on topdressing sortie.

PITCH CHANGE PIN

HC-C3YR-IRF/F8475R

8 4

94/3635 DEF MA 26/08/1994 BOE MOSGIEL Propellor blade pitch change peg failed during topdressing run causing severe vibration and loss of thrust. Aircraft returned to strip at full power in order to maintain 60 knots

Pitch change knob

HC-C3YR-1 DY2691A 8 5


00/4517 DEF MA 8/12/2000 EGT Waipukurau

The propeller blade pitch change knob failed while the aircraft was taking off. The whole propeller has been sent to Hartzell for further investigation.

Blade 8 6

01/3972 DEF MA 29/11/2001 DMO Beaumont The Fletcher took off on a spraying sortie when the aircraft experienced a severe vibration. The pilot managed to jettison the load and land on a plateau causing substantial damage to the undercarriage. He was not injured.

prop pitch change spigot

8 7

03/547 DEF MA 26/02/2003 DZC Tapawera The pilot reported that just after a load-drop the engine started to run rough. The engine was shut down and a force-landing was made into a paddock The aircraft slid down a back causing minor damage. All work relating to this prop failure to be logged u nder previous occurrence 01/3972.

Pitch change knob

HC-C3YR-1RF

8 8

03/1023 DEF MA 5/04/2003 DMU Patoka The pilot felt shake in nose area during start of take-off which was considered a nose wheel tire flat. Pilot pulled up wheel and aircraft was still shaking. Engine was shut down and pilot observed approxiamately 1/3 of Propeller Blade missing.

Propellor Blade

F8475R DY5361A 8 9

03/1971 DEF MI 18/04/2003 EGP Kerikeri During an inspection the propeller governor drive gear was found to be cracked.

Governor drive gear

8 10


03/1271 DEF MI 22/04/2003 CMK Wanganui No 5 Cylinder Intake Pipe found badly cracked around top flank.

8 11

05/3737 DEF MA 17/11/2005 EGW Hangawera The pilot experienced a severe vibration in the aircraft. The load was jettisoned and the aircraft returned to the airstrip.

Propeller Blade

F8475R DY3424A 8 12

06/4205 INC MI 30/10/2006 EUH Stratford It was reported that the aircraft propeller picked up a stone during loading and broke off aone tip of the blades. This was not discovered unitll there was a stopage for lunch.

8 13

07/911 DEF MI 7/02/2007 DZC Safe Air, Blenheim

The B4776 repair bush in the engine side of the hub has become completely displaced from the counter bore in the hub.

Repair Bush P/N B4776

HC-C3YR-1RF

DY 3839A 8 14

07/2080 ACC MA 10/06/2007 EMC Raupunga At the end of a topdressing run at approximately 100 feet above the ground a loud bang was heard. This was followed by a severe vibration and loss of engine power. A forced landing was made in very rough country that resulted in severe damage to the aircr aft but no injuries to the

il t

Propeller blade

F8483 J75739 8 15


07/4763 DEF MI 17/12/2007 EMW Rotorua Superair Ltd reported three separate prop indicated overspeeds. Aborted each takeoff. Engineer to RO to fix shorted wires. On the next start, smell of burning wires and panel went blank so aborted the start. Earth wires shorted. Main earth wire was f ound to have corrosion between firewall and earth wire.

Tacho 8 16

71/36 ACC MA 26/03/1971 CRF NR TAIHAPE

During the first takeoff from the airstrip the aircraft was slow to accelerate. jettison action was taken but the aircraft sank off the end of the strip and collided with a fence.

71-035 9 1

71/43 ACC MA 23/04/1971 CBG KAHAROA The aircraft sank after liftoff and before the load could be fully jettisoned the aircraft struck a ridge ahead.

71-042 9 2

71/55 ACC MA 20/05/1971 BVU TE MATA The aircraft experienced a sudden tail-wind gust as it became airborne, sank off the end of the strip and collided with a ponga tree. it remained airborne and returned to base

71-054 9 3

71/62 ACC MA 21/06/1971 CLO DANNEVIRKE

On takeoff the aircraft collided with a fence at the end of the strip. the pilot jettisoned his load and flew the aircraft to base.

71-061 9 4


72/18 ACC MA 3/02/1972 BVC PARAHEKA During sowing of superphosphate over hilly country, pilot found he had no alternative but to deviate from planned route, jettison load and attempt to climb over high ground ahead. with insufficient power to do so he was then committed to making a climbing turn, during which the aircraft stalled, squashed against the hillside, then slid down the slope.

72-015 9 5

72/28 ACC MA 24/02/1972 BWD KAIPAKI The pilot was spraying a large flat paddock of maize. on the second sortie a steep approach was made over a small group of boundary trees 80-100 ft high. the aircraft squashed into the crop, coming to rest half way along the paddock.

72-027 9 6

72/72 ACC MA 3/08/1972 CTO NR L TEKAPO

Following a snowfall, snow was brushed from the leading edges of the wings and a takeoff was attempted with nearly a full load. the jettison was operated to facilitate becoming airborne but the aircraft collided with the top of a fence. being unable to remain airborne the pilot closed the throttle and the aircraft came to rest in a ditch.

72-069 9 7


72/76 ACC MA 20/08/1972 DDA OTANE The pilot attempted a spray run up the side of a hill. the height difference between the bottom and the top of the hill was 600 ft. at the end of the spraying run the airspeed was so low that the aircraft squashed on to a ridge just beyond the brow of the hill.

72-074 9 8

73/36 ACC MA 15/02/1973 BXT WAIHOLA When the aircraft failed to return from a topdressing sortie a search revealed that it had crashed shortly after takeoff killing the pilot. the aircraft had stalled during climb-out, loss of control ensuing at a height which did not permit recovery before the aircraft struck the ground.

73-029 9 9

73/94 ACC MA 7/08/1973 DHO HOWARD RIVER

On the 11th takeoff from an airstrip progressively thawing out the aircraft accelerated more slowly than previously. partial jettisoning of the load was initiated at a point where the aircraft had formerly become airborne. as it was becoming airborne the aircraft collided with a fence. no evidence of unintended overload found. after examination no explanation found.

73-095 9 10


75/102 ACC MA 27/09/1975 CYZ NR WAINGAKE

Aircraft taking off from strip and climbing in circular pattern to cross ridge approx 100 ft higher than takeoff point. as aircraft approached ridge it entered a downdraught. pilot turned level with ridge and attempted jettison but unable to prevent aircraft from striking side of gully. fuselage and wings forward of hopper destroyed by fire after pilot escaped by breaking through jammed canopy.

75-097 9 11

76/77 ACC MA 25/06/1976 BHJ NR PAHIATUA

The pilot stated that he had noticed some frost on the wings and tail surfaces before the aircraft was loaded but had not removed it before takeoff. after becoming airborne the aircraft failed to gain height and collided with several fences before coming to rest.

76-073 9 12

77/12 ACC MA 25/01/1977 DMV ELSTHORPE The aircraft sank back onto the topdressing strip just after takeoff and the right aileron struck a gate post. the aircraft load was jettisoned and the pilot decided to remain airborne, flying to a nearby airport without further incident.

77-014 9 13


77/50 ACC MA 17/03/1977 BHY NR KAIKOU After liftoff on a topdressing sortie the aircraft was seen to drop a wing which carved a swath through tall scrub. the aircraft then rolled into an inverted attitude and dived into the ground

77-048 9 14

77/57 ACC MA 28/03/1977 CLO FLEMINGTON

The aircraft encountered a downdraught after takeoff and although the pilot attempted to jettison the load he was unable to prevent the aircraft from colliding with the adjacent terrain.

77-057 9 15

77/61 ACC MA 23/04/1977 BII NR KAEO A hang up occurred while sowing wet lime. the aircraft had received an unintended overload which could not be released while sowing a blind valley. the aircraft struck a ridge at the head of the valley and dived down a bank.

77-063 9 16

77/107 ACC MA 3/09/1977 CLI RAHOTU The aircraft failed to lift normally during the 6th takeoff from a wet strip. the flaps elevator and fuselage were damaged in a collision with a boundary fence despite the pilot's attempts to clear this obstruction by lowering further flap and making efforts to jettison the damp potash/superphosphate load.

77-107 9 17


77/141 ACC MA 5/12/1977 CMI NR DARGAVILLE

An inexperienced topdressing pilot did not select the best way to sow a block. he encountered a downdraught while turning onto the sowing run and retained his load until over the property to be sown. when the load was jettisoned he was too low to avoid high ground ahead.

77-142 9 18

78/67 ACC MA 27/04/1978 DSL GLENAVY While taking off from a level airstrip in a gusty tailwind, the aircraft took a longer run than normal and the load was jettisoned. the rear fuselage struck the fence as the aircraft became airborne in a tail-down attitude.

78-064 9 19

78/69 ACC MA 3/05/1978 CBG PURUA Although inexperienced, pilot had no difficulty with this strip for 25 loads. on 26th flight aircraft didn't lift off by the normal position along strip. company manager believed pilot's technique of allowing aircraft to adopt an excessively high nose attitude at liftoff combined with late decision to jettison caused tail of aircraft to collide with fence at end.

78-068 9 20


78/127 ACC MA 8/10/1978 BIK PAERATA On the second load after refuelling the aircraft sank after liftoff. the jettison was left too late and the aircraft struck a fence. on returning to the strip after sowing the load the pilot noticed that a light tailwind had developed. the wind was not indicated on the wind sock as it was made from material too heavy to respond to light winds

78-131 9 21

79/52 ACC MA 19/03/1979 EGB BIDEFORD Takeoff run appeared normal until failed to become airborne at rotation. pilot jettisoned some of load and aircraft lifted off but too late to avoid collision with fence at end of strip. remaining load dumped and pilot able to fly aircraft back to the strip for uneventful landing. probable that tail wind drift affected aircraft during latter stage of the takeoff.

79-055 9 22

79/57 ACC MA 27/03/1979 CTI FAIRFIELD While topdressing close to a residential area aircraft was observed to enter a steep turn at low altitude. the turn was progressively tightened and the angle of bank increased with the aircraft in a nose high attitude. during the turn aircraft stalled and although pilot jettisoned the load insufficient altitude available for recovery before colliding with terrain.

79-054 9 23


79/83 ACC MA 11/06/1979 DMJ NR MILTON The aircraft failed to become airborne on a topdressing sortie. the pilot in command was fatally injured when the aircraft rolled some 70 m downhill beyond the strip and impacted heavily on a small ledge.

79-081 9 24

80/29 ACC MA 7/02/1980 EMF NR WAIPUKURAU

On the first sortie of the day, the aircraft was seen to climb towards the sowing area in a steep nose up attitude. just short of the area to be sown the aircraft stalled, a wing dropped and the aircraft struck the ground inverted. a severe fire broke out at impact.

80-027 9 25

80/44 ACC MA 20/03/1980 EGV NR ROTORUA

While working off a level airstrip in varying tailwind conditions the aircraft lost height after takeoff and collided with a fence.

80-032 9 26

81/86 ACC MA 21/10/1981 CCT ORMONDVILLE

After takeoff the aircraft turned into a downdraught on the lee side of a ridge. the pilot attempted to jettison the load and turn away from the area but the aircraft continued to sink until it collided with the ridge.

81-083 9 27

84/108 ACC MA 11/11/1984 BIK NR MATAMATA

While taking off from a farm airstrip on the 14th sortie of the day the aircraft struck a fence. it became airborne briefly before striking a substantial tree and diving steeply into a gully.

84-114 9 28


85/45 ACC MA 9/05/1985 BVU NR GISBORNE

After takeoff the pilot made a steep left turn. the aircraft sank and rolled left so he jettisoned the load. the aircraft continued to sink and the left wing struck the ground and it cartwheeled.

85-045 9 29

86/33 ACC MA 20/03/1986 DHE WHAREPUHUANGA

While the pilot was turning in his seat to look at a loader, one of his boots became jammed in a rudder pedal. he was unaware of this until after the takeoff was started. the load was jettisoned as the aircraft became airborne off the side of the strip, damaging the elevator and wing on the edge of the strip.

86-031 9 30

87/53 ACC MA 6/05/1987 CBI NR MATAKANA

During the first takeoff from a topdressing strip the aircraft's tailplane collided with a boundary fence. part of the tailplane subsequently separated in-flight and the aircraft dived into the ground out of control. the pilot received fatal injuries in the accident. probable cause was that the pilot failed to jettison the load early enough to restore the aircraft's takeoff performance which had been degraded by the kikuyu grass on the airstrip.

87-055 9 31

87/108 ACC MA 24/11/1987 BIX WHAKAMARU

The aircraft struck the ground after takeoff due to a tailwind gust.

87-118 9 32


89/77 ACC MA 15/09/1989 BWV WHAREORA

During takeoff wheel drag was experienced due to boggy areas on the downhill airstrip. the pilot abandoned the takeoff but could not prevent it overrunning through a fence

89-079 9 33

90/17 ACC MA 19/01/1990 DUF NR TE ANGA

During the second takeoff of the day a tailwind gust occurred. the pilot's attempts to jettison the load of wet lime were unsuccessful and the aircraft sank off the end of the strip into a swamp.

90-016 9 34

90/89 ACC MA 19/06/1990 BHV KERIKERI AD

During takeoff from a long level airstrip a slight power loss occurred which degraded the aircraft's acceleration. the load was jettisoned but this did not prevent a collision with some scrub which caused the aircraft to slew and impact onto a road.

90-085 9 35

90/92 ACC MA 4/07/1990 DGE HIGH PEAK STATION, C

Towards the end of the takeoff a strong tailwind gust and downdraught was encountered. the aircraft's tailplane struck a fence and the fletcher sank down a steep face before striking the ground with its left wing and coming to rest against a tree.

90-093 9 36

91/453 ACC MA 28/08/1991 CZA Pahiatua Takeoff, hit fence 9 37

92/1017 ACC MA 20/04/1992 DHD nr Waikaremoana

Heavy, slow, stalled 9 38

92/3804 ACC MA 12/11/1992 EGH nr Dannevirke

Hit fence on farm strip takeoff, diverted, crashed

9 39


93/350A ACC MA 28/01/1993 DZF 10 N Dannevirke

Poor takeoff performance, jettison system failed

9 40

94/1155 ACC CR 29/03/1994 DZB 2 S Ngaruawahia

Manoeuvring low level, incipient spin, hit ground

94-010 9 41

94/1789 INC MI 19/04/1994 DZO TE ANGA ON T/O A/C RAN INTO AN AREA OF DOWN DRAUGHT AND SANK SLIGHTLY CAUSING ONE MLG TO HIT A FENCE POST.

9 42

94/2081 ACC CR 11/05/1994 CMG Argyll East Turbulence, aircraft sank, hit ground heavily

9 43

94/3633 ACC MA 18/09/1994 EGX Okaihau Excessively wet material, dump failed, hit hill

9 44

94/4134 ACC CR 3/11/1994 EFO Kaikohe Crashed shortly after takeoff 94-025 9 45

95/1273 ACC CR 7/05/1995 EMB 8NM NE TAUPO

TOPDRESSING ACFT ON THE THIRD SOWING RUN OF THE DAY IMPACTED ON LEVEL GROUND SOME 8KM NORTH EAST OF TAUPO.

95-007 9 46

95/1541 ACC CR 8/05/1995 JAL TE AKAU AIRCRAFT OVERRAN RUNWAY AND CAME TO REST IN A BANK.

9 47

95/1708 ACC CR 6/06/1995 EMU LAKE GRASSMERE

AIRCRAFT FOUND BURNT OUT AFTER COLLISION WITH THE FACE OF A HILL

95-010 9 48


95/3614 ACC MA 24/10/1995 BHJ HOKITIKA A Fletcher top dressing aircraft was engaged in agricultural operations sowing lime from the Raft Creek airstrip in the Kokatahi Valley on the West Coast of the South Island. Satisfactory performance was being achieved with 14 loads of one tone each for4 5 minutes. On the 15th consecutive load the aircraft failed to reach decision point speed and despite an attempted jettison of load the aircraft impacted with a fence at the end of the strip as the aircraft was becoming airborne. The jettison was completed and the aircraft landed for inspection.

9 49

95/3133 ACC CR 1/11/1995 EUG RANGOIO STATION

Aircraft impacted with ground during topdressing operations.

95-018 9 50

96/1145 ACC MA 23/03/1996 EMN Otapari Gorge

During take off run aircraft outer panel hit fence post. Minor damage to elevator trim tab.This was the first take off of the day on a wet strip and it appears the pilot may have miscalculated the take-off distance.

9 51


96/2415 ACC MA 6/09/1996 BDS Manawahe Topdressing aircraft was flying into a narrowing gully and towards a ridge. Pilot realised too late there was insufficient performance to clear the ridge. Attempted to dump the 750 kg load. Did not release. Hit top of hill.

9 52

96/2551 ACC MA 21/09/1996 CDZ PUIRI Failed to get airborne - due wind gust. Engine operating normally.

9 53

97/91 ACC CR 21/01/1997 EHX 8 WSW Taihape

Whilst conducting topdressing operation, aircraft impacted with terrain in descending turn. 1 Fatal, aircraft destroyed.

9 54

97/492 ACC MA 24/02/1997 DZF East Dannevirke

The pilot was sowing into a narrow, rising valley when he encountered heavy sink. Unable to turn within confines of valley and despite application of full power, 20 degree flap and payload dump, he failed to establish a climb. Aircraft stalled and impact ed valley side. Pilot injured. Aircraft destroyed.

9 55

97/2568 ACC CR 29/08/1997 DIL FAIRLIE While positioning for a spreading run, aircraft encountered loss of lift. Crashed into paddock 5nm South East of Burkes Pass. Substantial damage.

9 56


99/1481 ACC MI 19/03/1999 DLQ Waituna West

The aircraft encountered sink during the takeoff and stuck a fence post at the end of the runway. It remained airborne and was flown back to base. Damage was caused the right hand flap.

9 57

99/732 ACC CR 27/03/1999 EMV nr Riversdale Beach

Significant event: The aircraft, with a 23-hundredweight load, became airborne but sank rapidly off the end of the strip in a nose-high attitude. It collided with a fence, damaging the left wing spar and the tailplane. At this point load jettisoning wa s observed, and the aeroplane climbed briefly before rolling to the left and striking the ground inverted. The pilot was killed in the final impact.

99-002 9 58

99/2831 ACC MA 28/09/1999 DLS Raetihi The pilot reported that, on the take-off roll, the engine appeared to overspeed and the aircraft failed to take off. It sank into a shallow gully off the end of the strip

9 59

00/614 ACC MA 9/03/2000 LAY Te Miro On the first flight after refuelling, the aeroplane was taking off on an uphill strip with a quartering tailwind. The pilot commenced jettisoning the load when he realised he was not going to get airborne. The aeroplane collided with a deer fence and a trough on the lower side of the strip. The pilot was not injured.

9 60


00/4078 ACC CR 14/12/2000 BHL Raglan, Te Akau

The aircraft took off from an airstrip near Raglan (Te Akau) failed to become airborne and crashed into the hillside. The aircraft was destroyed in the accident

9 61

01/2183 ACC MA 26/06/2001 EMW Mangapai The aircraft sank after takeoff and hit a fence post with the left wing, which damaged the aileron. The pilot managed to circuit and land safely.

9 62

01/2806 ACC MA 19/08/2001 EMN Dipton West

On the 17th flight from the strip, the right main undercarriage struck a clump of tussock or similar obstruction and became partially detached. The pilot reported also that a rectangular hole was torn in the top surface of the wing. He diverted to Gore (company base) where the trailing wheel caused further damage to the right flap on landing.

9 63

01/3065 ACC CR 7/09/2001 CMN Waiotira The aircraft failed to become airborne within the length of the airstrip. The left wing struck a fence then scraped the ground. The pilot jettisoned the load and became airborne but was unable to control the aircraft and prevent it from impacting ground .

9 64


01/3127 ACC MI 14/09/2001 SAJ Mangatahi The Fletcher clipped a fence at the end of the airstrip on takeoff. The pilot jettisoned the load and carried out an emergency landing in an adjacent paddock. Damage was limited to the undercarriage and the the fuselage underbelly.

9 65

01/4371 INC MI 4/12/2001 JAA Pahoia During the 3rd takeoff run the pilot realised he may not clear the fence so he jettisoned the load. The aircraft lifted off but the tail cone just clipped a fence. The pilot landed and inspected the area for any damage and then flew back to the maintenan ce base for a further inspection.

9 66

01/4194 ACC CR 23/12/2001 MAT Hukerenui The aircraft took off from an airstrip with a load of lime. The pilot then entered the sowing area which was a valley system in hilly terrain. The pilot attempted to dump the load but the aircraft hit some trees then the ground and caught fire. The pil ot was killed.

9 67

02/1262 ACC MA 25/04/2002 EUH Opunake During the takeoff the pilot realised that the aircraft was not accelerating as it should . He dumped the fertilizer became airborne but clipped the fence with the right wing. The pilot decided to divert to Stratford where he landed safely. The aircraf t sustained minor damage.

9 68


03/15 ACC MA 7/01/2003 DMO Waitahuna The pilot lined up on the sloping airstrip, but picked the wrong reference point on terrain visible beyond the crest. On the takeoff roll, he found that as he came over the crest, he was about 25 degrees off the line of the strip. He commenced jettisoni ng the load but was unable to clear the head of a small gut adjacent to the strip.�The aeroplane was substantially damaged, but the pilot was uninjured.�

9 69

03/3733 ACC CR 19/12/2003 BXZ 10 SW Te Kuiti

The aircraft descended after takeoff and flew into a small ridge a few degrees off the runway centreline fataly injuring the pilot.

9 70

05/2301 INC MI 30/04/2005 BHK Lumsden The pilot reported that the aircraft experienced a lime hang-up while sowing a 35 tonne of lime, the product would not flow from the hopper door.

9 71

06/1135 ACC CR 31/03/2006 EGP Kaitaia It was reported that an aircraft carrying out agricultural operations has had a fatal accident near Brass Road, Kaitaia. There was only the pilot on board.

9 72

08/984 INC MI 27/02/2008 EGT Wanstead Left flap trailing edge contacted the top of a fence post during a takeoff sustaining minor damage.

9 73


08/1400 ACC MI 3/04/2008 DLQ Opotiki The aircraft was taking off from a farm strip when it was caught in a downdraught as it crossed a small gulley.Despite the pilot initiating a jettison of the load the aircraft the aircraft continued to sink and struck a fence. The impact caused a main un dercarriage leg to fold rearwards. The pilot flew on to Opotiki and made a successful landing.

9 74

08/1714 ACC CR 25/04/2008 DZC Kaihoka Lakes

The topdressing aircraft collided with terrain during the take-off. The pilot lost control soon after the collision and during the ensuing accident he was seriously injured and the aircraft was destroyed.

IMcClellan 9 75

93/2205A DEF MI 17/08/1993 EMX ARDMORE TRANSISTOR 10 1

95/1821 INC MI 22/06/1995 DLQ NEW PLYMOUTH

A/C HEARD CIRCLING THE AERODROME. NO CALLS RECRIVED, A/C DID STANDARD O/H REJOIN FOR RWY 23. GIVEN GREEN LIGHT TO LAND. PILOT REPORTED TO TWR HAD DIVERT DUE WX AND HAD RADIO FAILURE

10 2

95/1906 DEF MI 22/06/1995 BHG HAMILTON A new emergency locator transmitter self activated whilst aircraft on ground and not being worked on.

Emergency locator transmitter

53501 10 3


04/2783 INC MI 27/08/2004 JAA Tauranga Airways reported that ZK-JAA called 10NM to the west of NZTG. During the transmission, the transmission cut out and only carrier wave was received. However, the TG TWR controller issued zone entry instructions. The flight called again at the sports ground and circuit joining was provided. However, light signals were used to confirm landing clearance when the aircraft was on final.

10 4

04/2805 DEF MI 29/08/2004 JAA Tauranga Airways reported that the aircraft taxied onto grass 25 and got airborne without making any RTF contact with the tower, which had been on watch for ten minutes. The pilot reported that he made calls and saw people in the Tower as he flew past. He called t he Tower from his destination and established he had a radio problem.

Radio 10 5

07/395 DEF MI 7/02/2007 EML Airways reported that the aircraft experienced communications failure and squawked 7600, entering WB CTR at Okaramio and subsequently flying the DOMES arrival to NZOM.

10 6

07/1990 DEF MI 2/05/2007 DHE Auckland On retraction to Flaps 2 the Leading edge amber light remained illuminated

loose switch H/O 1026-2 9025 10 7


07/1987 DEF MI 23/05/2007 DHE Auckland Asian Express Airline reported that during the climb just after takeoff from Auckland the aircraft failed to pressurise. A fuel dump was carried out and the aircraft returned to Auckland.

Broken Wiring

10 8

08/391 DEF MI 28/01/2008 EME Taupo The pilot reported that while airbourne he noticed that the Generator was not charging.�On landing he found that the Starter/Generator had detached from it's mounting point.

Starter/Generator

LUN2132.02-8

5830920 10 9

08/1462 DEF MI 4/04/2008 JSW Gore ELT antenna broken just above antenna block (diode).

Antenna 110-773 10 10

08/1883 DEF MI 28/04/2008 DUJ Hamilton During a functional ELT self check the "G" switch was found not working.

Me406 "G" switch

453-6603 01952 10 11

08/2224 DEF MI 23/05/2008 EMG Gore Aviation Maintenance reported an Antenna broken after 70hrs in service. Broken just above diode block on Antenna.

Antenna 110-773 10 12

08/3477 DEF MI 13/08/2008 DUJ Pukehoe East

Refer to Engineering. Me406 Artex ELT

10 13

08/3682 DEF MI 20/08/2008 DUJ Hamilton Superair Ltd reported on DUJ's ELT follow-up ME406 - went off by itsellf (first time this had happend). Two days later it went off again.

10 14

08/3056 DEF MI 17/07/2008 DUJ Hamilton Superair Ltd reported remote switch LED light on permanently.

ELT 453-6603 07437 10 4


92/830 INC MA 31/03/1992 CDZ PMCTR SHORTLY AFTER TKOF RWY 25 BOUND YP ACFT REQUESTED LDG RWY 25 DUE SERIOUS NOSE UP PROBLEM, EMERG SERVICES ALERTED AND ACFT LANDED SAFELY

11 1

94/1345 DEF MA 15/02/1994 JAC WHANGAREI

A CONTROL CABLE HAD BROKEN THROUGH MORE THAN HALF ITS BRAIDS.

CABLE CAB-D-14-83-2624

11 2

94/4207 DEF MA 6/11/1994 EMN INVERCARGILL

CONTROL CABLES PREMATURE WEAR.

FLT CONTROL CABLES

11 3

94/4246 DEF MA 9/11/1994 EGV IN FLIGHT RUDDER JAMMED IN NEUTRAL POSITION.

RUDDER 24 2401 11 4

95/2389 DEF MA 7/08/1995 CBA OROPI While aerial topdressing rudder pedal's went slack. Realizing still had control of aircraft proceeded back to airstrip. Discovered rudder torque tube broken.

TORQUE TUBE

242409 11 5

96/1574 DEF MA 4/06/1996 EGU HAMILTON Throttle cable appears to have fatigued and subsequently broken approx 12 inches from engine throttle fork end. Suspect routeing fault.

THROTTLE CABLE

243357-2 11 6

97/2864 DEF MA 16/09/1997 DHD Fielding Elevator trim system found to be installed incorrectly.

Trim drum 11 7

97/2865 DEF MA 16/09/1997 DHD DANNEVIRKE

Flight control cables found to be installed grossly over tensioned.

Cable tension 11 8


97/2863 DEF MA 25/09/1997 DHD FEILDING Aircraft elevator cable worn excessively and over tensioned from rebuild. Also trim assembly jammeing and found to be assembled incorrectly. Concerned at the potential for fatal accident. Aircraft was rebuilt at United Aviation but was sent to Aero Suppor t Fielding where fatal flaws were found.

11 9

99/3510 DEF MA 10/12/1999 EOE NEW PLYMOUTH

The Fletcher FU24 pilot called at Oakura, west of New Plymouth, to advise he was joining and had a broken rudder cable. He was anticipating handling and control problems on finals and after landing. A local standby was declared however the aircraft landed safely.

Rudder Cable 11 10

00/3448 DEF MA 30/10/2000 JSW GORE Engineering noticed abnormal wear in the Power Lever and Quadrant Gate in the cockpit that required the removal and replacement of both items.

Power Lever & Quadrant Gate

TCL 06-004-1

11 11

03/3950 DEF MI 29/12/2003 DHD Fielding On the pre flight check the pilot noticed stiffness in the elevator. After a few movements and a small amount of force the stick moved freely without any further problems. On take-off the aircraft was extremely nose heavy. The aircraft re-circuited and l anded safely.

Horn Trim Tab

242532-8 11 12


04/1028 DEF MI 10/03/2004 EUH Wanganui It was reported that during the 100 hour inspection the flap control handle ratchet was found cracked where it is welded to the tube.

Handle ratchet mount

08-45911-1 11 13

04/2760 DEF MA 19/07/2004 EUH Wanganui Wanganui Aero Work reported that the aircraft's direct aileron cables were found badly worn.

Aileron Control Cable

242597 11 14

04/4278 INC MI 4/11/2004 EGV Hamilton Super Air reported that ZK-EGV just had a new electric trim switch fitted. Shortly after take off the pilot applied forward trim which evidently resulted with the opposite occurring and the nose of the aircraft lifted.

Maintenance error

11 15

04/4111 DEF MI 22/11/2004 EGS Aero Support

It was reported that the right hand aileron cable, fitted at 7512 hours, was found worn after 7986 hours TIS.

Aileron Cable 11 16

04/4099 DEF MI 30/11/2004 CRY Hamilton It was reported that the aircraft pulley bracket that is holding the aileron pulley to the side of the cockpit has a crack at the attachment end.

Pulley bracket

11 17

05/195 DEF MI 28/01/2005 EUC Napier During a routine maintenance aileron cable inspection, as per DCA/FU24/174, it was revealed that several aileron control cables were worn to M.M limits some with broken wires.

Aileron Cables

242671, 672, 597

11 18

05/1216 DEF MI 7/04/2005 JNX Hamilton The pilot reported that the elevator control was noisy and notchy.

Elevator pulley

11 19

05/1274 DEF MI 11/04/2005 EMG Gore During inspection it was found the plug in the end of the aileron push rod was working.

Aileron push pull rod

242502 11 20


06/2388 DEF MI 19/03/2006 EMW Rotorua During landing a problem with the flaps was experienced.

Flap torque tube

242552 11 21

06/1304 DEF MI 2/04/2006 EUH Wanganui An investigaation into an inservice defect found that the throttle cable was found broken.

Throttle Cable

24 1624-1 11 22

06/2482 DEF MI 3/06/2006 EUH Wanganui The aircraft's hopper control lever broke off during a ground run.

Hopper control lever

249479 11 23

07/436 DEF MA 7/02/2007 EGV Whakatane The pilot reported that during the take off the elevator became stiff to operate.

Elevator rear pulley

11 24

07/2685 DEF MI 8/07/2007 EFM Hamilton Super Air reported that riverts found to be very loose which caused aileron control loss.

11 25

07/3839 DEF MI 17/10/2007 EME Taupo It was reported that pilot noticed a vibration in the Rudder Pedals. The vibration was difficult to replicate on demand but was noticeable in the climb at climb power settings with 3 notches of flap at 70-80 kts.

Hopper Fairing

256 11 26

08/1385 INC MI 14/02/2008 EMW Rotorua Super air Ltd reported trim failed over a couple of days would work for a while and then stop again. Flown to HN where the trim motor was replaced.

11 27

08/2286 DEF MA 20/05/2008 EMX Hamilton Defect report - Submitter reported Aileron L/H spar found cracked during routine inspection.

SPAR 241506-2L

241538L 297 11 28


08/3992 DEF MI 25/08/2008 EMW Hamilton SuperAir reported over a period of time, the pilot noticed a slight jamming of the control column and this got progressively worse to where the pilot had to move it to the left and then back to the right to get free movement. Jamming was always when tryi ng to roll to the right from a LH turn. Once fixed it was very noticeable how free and light the control column movement was.

Aileron 11 29

91/1218A INC MA 29/12/1991 BOF KAWERAU FORCE LANDED DUE ENG PROBLEM. PILOT SUSPECTED FUEL SABOTAGE. Nature of the occurrence

12 1

93/2461 INC MA 3/06/1993 DYJ GISBORNE A/C JUST AIRBORNE RETURNED TO LAND WITH STRONG SMELL OF AVGAS IN COCKPIT.

12 2

00/3286 DEF MI 20/09/2000 EMN GORE During an inspection it was found that 2 of the stabiliser balance weight attachment lock nuts were loose. This was possibly due to repeated use or incorrect tightening in the past.

Barrel nuts 1452-048 13 1

03/3946 INC MI 15/12/2003 EUH Taranaki area

It was reported that the aircraft's tailplane just clipped a cow before touchdown while landing on a farm strip. The leading edge skin and ribs were badly damaged so the elevator was replaced.

LH Leading edge

13 2


07/3028 DEF MI 20/08/2007 EUF Taieri During a routine inspection a crack 1 1/2 inches long was found on the stabilator spar main beam top angle just inboard of the RH upper skin attachment.

Angle - Main Beam - Top

242209 13 3

08/937 DEF MA 20/02/2008 CRY Hamilton Super Aid Ltd reportedf further investigation around area of working rivets on RH outer panel revealed outer RH spar web and lower cap cracked at 100 hr inspection at Hamilton Hanger (Super Air Ltd)

14 1

02/3757 DEF MI 24/10/2002 DUJ Masterton After finding other cracks in the airframe the engineers removed the hopper and found several more stress cracks in areas which cannot be normally seen in a standard 100 hour check.

Fuselage components

196 15 1

06/396 INC MI 11/01/2006 JNX Huntly Super Air reported that the hopper lid detached due to cracking in the framework during the flight.

15 2

06/479 DEF MI 4/02/2006 JNX Rotorua Super Air reported that the hopper detached itself from the aircraft during flight. It was left in place only by a piece of rope.

Hopper Lid 15 3

07/364 INC MI 21/01/2007 CRY Matammata

The aircraft was in the cruise when the bottom of the lift up canopy flew up and caused damage to the right hand side before detaching and falling to the ground.

Canopy 15 4

08/2143 INC MI 20/05/2008 EME Taupo Fertiliser deflector plate attached under the aircraft was seen to be flexing during flight.

TCL 09 101 1 TCL-09-101-6

15 5


87/24 ACC MA 13/02/1987 DZA NR ORARI GORGE

After 100 tonnes of fertiliser had been sown on a hill country station, a spreader unit was attached to aircraft and pilot took off to sow pellets on higher country on same property. 5 mins later the aircraft landed and came to rest abruptly on a spur. personnel who reached the aircraft with a minimum of delay found aircraft extensively damaged and pilot dead. probable cause was an inflight medical incapacitation which prompted the pilot to attempt to land without delay.

87-046 16 1

88/100 ACC MA 27/12/1988 EMZ NR RANGITATA

The pilot was engaged in spraying a potato crop. towards the completion of this task the aircraft dived into the ground during a turn. probable cause of the accident could not be established. findings; aircraft dived into the ground during a reversal turn. the mixture of chemicals being sprayed contained a concentrate classified in toxicity as a dangerous poison. pilot did not ensure he was fully protected against the mixture during loading. not determined if any (f3 for more)

88-098 16 2


06/1021 INC MI 25/03/2006 DJE Motueka The pilot felt some chest discomfort after take off and after a couple of minutes decided to descend and land. About 3 hrs later after feeling worse he was taken to A&E where he was diagnosed with a collapsed lung. The pilot had suffered a chest infection prior to this event that had been treated with antibiotics.

16 3


OCC No Code SevDate Time

UTCReg Location

Description Part Defective P/ N Part S/N TAIC Ref Class Total

91/35 DEF MA 10/01/1991 LTR WANGANUI 0 1

91/256 DEF MA 25/05/1991 LTQ INVERCARGILL 0 2

91/1278 DEF MA 14/10/1991 LTS WANGANUI 0 3








92/2575 DEF MA 20/03/1992 LTS UNKNOWN 0 11



Annex F: Cresco Occurrences Page 127





93/1811 DEF MA 26/02/1993 JAD TAUPO 0 18

93/1472 DEF MA 11/03/1993 LTQ INVERCARGILL 0 19


93/2339 DEF MA 12/05/1993 TMN HAMILTON 0 21

93/2459B DEF MA 2/06/1993 JAD TAUPO 0 22

93/2728 DEF MA 8/06/1993 LTP NAPIER 0 23

93/2729 DEF MA 8/06/1993 LTP NAPIER 0 24

94/1716A DEF MA 18/04/1994 JAD HAMILTON 0 25

94/3956 DEF MI 19/09/1994 LTS WANGANUI FLANGE 08-40027-2 0 26

95/3668 DEF MA 13/09/1995 LTR WANGANUI Bell crank mount tube

08-11219-1 0 27

01/1783 DEF MI 25/03/2001 LTT Napier Angle capping cracked at l/h side from relief cut out. Angle Capping 0 28

96/2641 DEF MA 19/08/1996 LTR WANGANUI Rear fuselarge frame P/N 08-11125-12 Frame 08-11125-12 1 1



UTCReg Location


97/3830 DEF MA 1/12/1997 LTW MALAYSIA During maintenance the rudder almost came off when an engineer applied pressure to the top rudder hinge.

top hinge 08-32037-1 1 2

97/3831 DEF MA 1/12/1997 JAD MALAYSIA During maintenance the rudder almost came off when an engineer applied pressure to the top rudder hinge.

Top hinge 08-32037-1 1 3

97/3832 DEF MA 1/12/1997 LTQ MALAYSIA During maintenance the rudder almost came off when an engineer applied pressure to the top rudder hinge.

Top hinge 1 4

98/1059 DEF MI 9/04/1998 TMM TAUMARUNUI A pilot of a light aircraft noticed that the top of the rudder had a lot of side movement.

RUDDER TOP RIB

1 5

99/780 DEF MI 17/03/1999 TMM HAMILTON n/a UPPER RIB 08-33035-1 1 6

99/1892 DEF MA 15/06/1999 LTX NAPIER During a routine inspection (100 hour) the rudder top attachment was noted to be lose. On removal it was found that the anchor nut was torn away from

Rudder top attatchment

1 7


the rib.�It appears that there was at least four holes drilled 2 leg anchor nut

99/2731 DEF MA 16/08/1999 LTX NAPIER During routine inspection, the rudder tip attatchment plate was found to be missing riviets on both sides.

Rudder 1 8

00/1690 DEF MA 22/05/2000 LTU NAPIER The vertical fin skin had a 6 inch long cracked from adjacent the top of the rudder mount bracket. It is suspected excessive loads have been imposed on skin.

SKIN CRACKED 08320014 014 1 9

00/1769 DEF CR 26/05/2000 LTT MATAMATA Significant Event. During topdressing operation, loader driver noticed vertical fin movement during taxi up to loading area and previous take-off. Examination of area revealed fractured vertical stabiliser Forward fitting. Forward location only held by dorsal fin attachment screws most of which were ripped out.

fitting - forward fin attach.

2430172 NSN 1 10



UTCReg Location


01/3778 DEF MA 23/10/2001 WAT Christchurch During the pre-flight inspection the pilot noticed excessive movement of the rudder at the upper pivot bolt location. Closer inspection revealed that the upper pivot bolt nut had detached and caused elongation of the bolt hole in the rib.

Rudder attachments.

1 11

02/2467 DEF MI 8/08/2002 LTT Napier During a check of the upper rudder hinge bracket a crack was found in the rib pivot attachment.

Upper rudder rib 08-33035

1 12

03/835 DEF MI 4/03/2003 LTE Napier During routine maintenance inspection of the rudder top hinge location revealed a cracked rib. The rib was renewed.

Rudder rib 1 13

03/1896 DEF MI 8/06/2003 LTE Napier The rudder top rib was found cracked around the anchor nut periphery during a routine inspection.

Rudder top rib 08-33035-1 1 14

03/1996 DEF MI 30/06/2003 LTA Napier The upper rib was found cracked around the Rudder top rib 08 33035 1 1 15


03/1996 DEF MI 30/06/2003 LTA Napier The upper rib was found cracked around the counter sunk rivet head location that holds the upper pivot bolt anchor nut. �As previously reported the ribs thickness does not seem to contain any fatigue.�

Rudder top rib 08-33035-1 1 15

03/2355 DEF MI 23/07/2003 LTX Napier During a routine inspection of the rudder area the upper rib was found to be cracked.

Upper Rib 08-33035-1 1 16

03/2847 DEF MA 9/09/2003 TML Hamilton The pilot noted the aircraft's rudder sitting at a abnormal angle after delivery for a 100hr inspection.

rudder upper rib

08-33035-1 1 17

04/1665 DEF MA 23/03/2004 LTX Napier It was reported that the rudder spacer was found with side flanges cracked.

Spacer 08-33041-1 1 18

04/1305 DEF MI 21/04/2004 LTY Wanganui It was reported that during the 100 hour inspection the veretical fin front mount was found broken off.

Front Mount 243017-2 1 19

04/1803 DEF MA 31/05/2004 LTH Wanganui It was reported that whilst changing the fin mount from aluminium to steel, the original fitting was found cracked one third to half way across.

Front Mount 243017-2 1 20



UTCReg Location


05/1415 DEF MI 19/04/2005 NZO Queenstown There were a number problems found whilst trying to fit modification PAC/CR/0427 to a Cresco 08-600 aircraft.

Rudder top hinge

PAC MOD CR 0427

1 21

05/2942 DEF MA 24/08/2005 LTX Napier During a scheduled inspection of a Cresco aircraft the fin leading edge skin was found to be cracked at the top of bulkhead P/N 242305-2 attachment.

Fin Leading Edge

08-32001-4 1 22

07/1266 DEF MI 2/04/2007 EEL Taieri Fin leading edge skin found cracking from top of cut-out area for PN: 242305-2 bulkhead.

Leading Edge Skin

242308-3 1 23

83/34 ACC MA 19/03/1983 LTR L TAUPOThe right wheel and oleo piston separated from the aircraft as it touched down during the landing run following a topdressing flight.

83-036 2 1

93/2459A INC MA 3/06/1993 JAD TAUPO ON T/O WITH FULL LOAD, PILOT FELT KNOCK UNDER A/C, DISCOVERED WHEEL MISSING UNDERTOOK EMERGENCY LANDING WITH MINIMAL TO NO DAMAGE

2 2


DAMAGE.

93/4005 DEF MI 20/08/1993 TMN LANDING GEAR

245106 2 3

93/5343 DEF MA 7/11/1993 LTS WANGANUI NOSE WHEEL STEERING POST

08-45661-2 2 4

93/5724A DEF MA 9/12/1993 TMN OKAHUKURA MLG LUG ATTCHMENT BOLTS

AN5-37A & AN5-40A

2 5

93/5724 ACC MA 10/12/1993 TMN 5 N Taumarunui Right undercarriage leg collapsed on landing 2 6

94/4528 DEF MA 1/12/1994 TMN HAMILTON PILOT REPORTED PORT MAIN LANDING LEG AT AN UNUSUAL ANGLE

ATTACHMENT BOLT

NAS 1306-78 2 7

95/2061 DEF MA 19/04/1995 LTR WANGANUI . Steering post 08-45661-2 2 8

96/584 DEF MA 15/02/1996 LTP NAPIER Masin landing gear. Bolt head separated from stem. bolt AN5 -40A 2 9

96/3649 DEF MA 26/10/1996 LTT MALAYSIA Aircraft parked overnight and observed the next day to have undercarriage collapsed on the RH side.

CYLINDER 08-40027-3 CLMG - 006

2 10



UTCReg Location


97/593 DEF MA 29/01/1997 TMN TAUMARUNUI Three MLG attach bolts failed allowing gear to rotate rearward, which caused flap, rear spar and skin damage. these bolts have failed before on this aircraft but no other Cresco is having this problem.

BOLTS 3 MA21250-06078

2 11

97/1711 DEF MI 4/04/1997 LTS WANGANUI Nose wheel steering post cracked at lower bearing flange.

Steering post 08-45661-2 2 12

97/2107 DEF MA 7/05/1997 LTS WANGANUI The main wheel axle was found to be badly cracked at the mounting. The flange was very close to breaking off.

Axle 2 13

97/1710 DEF MI 8/05/1997 LTR WANGANUI Nose wheel steering post cracked at lower bearing flange.

Steering post 08-45661-2 2 14

98/3774 DEF MI 24/02/1998 LTU NAPIER During maintenance the LH main landing gear was found cracked.

left hand cylinder

08-40027-3 CLGM009

2 15

98/3775 DEF MA 5/03/1998 LTT New Zealand During normal landing the right hand main landing gear assy departed the aircraft The aircraft's right

cylinder 08-40027-3 clmg 003 2 16


gear assy departed the aircraft. The aircraft's right hand wing slid down onto the ground and the aircraft came to a stop.

99/874 DEF MI 10/02/1999 EEL TAIERI n/A 08-40021-1 AXLE

08-40021-1 2 17

99/2570 DEF MI 30/08/1999 TMM HAMILTON The right hand main landing gear lug attachment bolts (3) the rear bolt with head missing found by Pilot during preflight inspection.

Bolt NAS1305-58 2 18

00/227 DEF MA 17/01/2000 TMM HAMILTON During routing maintenance the cylinder flange at the torque link was found cracked. On dismantling a piece was found completely adrift. The manufacturer has the unit for investigation.

Cylinder 08-40051-1 2 19

00/448 DEF MA 15/02/2000 PWT NAPIER In carrying out check as per Service Bulletin cracks were found on the main landing gear axles.

Axles 08-40021-1 2 20

00/2854 DEF MI 2/08/2000 LTY WANGANUI Nose wheel steering tube broke off at weld. Steering tube 2x 5235-2 2 21



UTCReg Location


00/2631 DEF MI 3/08/2000 LTT NAPIER Durning routine inspection, righthand MLG cylinder lower flange found with section of flange including rear lefthand lug attachment bolt hole cracked off. This is a known fault.

cylinder 08400511 048 2 22

00/4495 DEF MI 22/11/2000 LTY Wanganui The nose wheel steering pivot pin was found broken at the clevis pin cut out.

Pivot pin 08-45711-1 2 23

01/366 DEF MI 9/01/2001 WAT NAPIER The hopper 'stress band' was cracked at its left and right hand extremities.

Stress Band 2 24

01/1254 DEF MI 20/02/2001 LTV Wanganui The left hand main under carriage cylinder was found to be cracked vertically under the lower clamp joint.

Cylinder 08-450051-1 C4MG 021

2 25

01/2162 DEF MI 11/05/2001 LTT Napier During an inspection the main landing gear cylinder flange was found to be cracked near the forward bow hole.

Cylinder flange 2 26

01/3431 DEF MI 6/09/2001 LTS Wanganui The left hand main under carriage was found to be leaking fluid due to a cracked leg cylinder

cracked cylinder

2 27


leaking fluid due to a cracked leg cylinder. cylinder

01/3432 ACC MI 4/10/2001 LTC Hunterville

While landing on an airstrip the left main undercarriage leg broke off causing the aircraft to slew left and stop short of departing the airstrip. Engineers later jacked the aircraft up, replaced the leg and had it flown back to Wanganui.

L/H Main 08-40051-1 072 2 28

01/4053 DEF MA 4/12/2001 LTX Napier As the Cresco taxied from the loading area, the pilot felt the left main landing gear collapse. The aircraft returned to base where it was found that the cylinder had cracked circumferentially below the lower clamp.

MLG 2 29

02/238 INC MA 29/01/2002 LTZ Hunterville The Cresco was turning in the loading area when the right main undercarriage leg broke off without any prior warning.

R/H Main u/c cyclinder

08-40051-1 77 2 30

02/842 DEF MI 15/02/2002 LTZ Palmerston North The Cresco's landing gear axle was found cracked in the flange radius.

Landing Gear 2 31

02/1079 DEF MI 16/02/2002 TMN Taumarunui The pilot reported that the right main landing gear cylinder was leaking oil.

MLG Cylinder 2 32



UTCReg Location


02/699 DEF MA 5/03/2002 TMN Hamilton During a 100 hour inspection it was found that the right rear main spar attachment and the associated area were all excessively worn.

Right main spar

2 33

02/850 DEF MI 5/03/2002 LTA Napier While complying with an SB an undercarriage MLG cylinder was found cracked.

MLG cylinder 2 34

02/2318 DEF MI 23/07/2002 LTX Napier During a routine inspection of the main landing gear a crack was found round the root radius of the axle stub.

Axle 08-40021-1

2 35

02/2901 DEF MI 20/09/2002 LTX Wanganui Flight Care supplied two Cresco axles for fitting to the aircraft. It was found, by magnetic particle inspection, that both axles were cracked in the flange radius area.�NOTE: Duplicate of 3/SAI/186.

Axles 2 36

The near new Cresco was taking off when an undercarriage leg collapsed causing the aircraft to

Oleo 2 37


02/3231 ACC CR 13/11/2002 TML Aria

undercarriage leg collapsed causing the aircraft to veer of the strip and down a bank where it suffered major damage. The pilot was not hurt and the weather was fine and airstrip condition good.

02/3578 DEF MI 26/11/2002 TMN Hamilton During routine inspection axles removed for magnetic particle inspection. Both LH and RH MLG axles found cracked.

Axle 08-40021-1 2 38

03/779 DEF MA 13/03/2003 LTY Wanganui While stopping to refuel it was noticed that the right hand main undercarrage leg was on an angle. On inspection it was found the lower front leg mount bolt had failed.

Lower Front Mount Bolt

NAS 1306 - 78

2 39

03/837 DEF MA 16/03/2003 LTL Wanganui The right hand main undercarriage cylinder was found to be cracked around the lug mount flange.

RH Main Undercarriage Cylinder

08-40085-1 011 2 40



UTCReg Location


03/1369 INC MA 3/05/2003 LTA Gisbourne The pilot declared a MAYDAY with the intention to land at Gisborne so a full emergency was declared. On arrival, the flight carried out a low pass in front of the tower for an assessment of the nose wheel, which appeared to be normal. The flight then land ed safely on grass runway 14.

2 41

03/1446 DEF MI 8/05/2003 TML Hamilton The right hand axle was found to be cracked around its axis during a magnetic particle inspection.

Axle 08-40021-1 2 42

03/2218 DEF MI 11/07/2003 LTH Wanganui The nose wheel steering port to yoke pin was found broken off. �Suspected that pin hole had been filed larger at some stage, which is a normal practise.��

steering yoke attachment pin

08-45711-1 2 43


03/2400 DEF MI 8/08/2003 TMN Hamilton During maintenance some suspicious pit markings were noticed on the chrome of the main landing gear oleo piston.

Oleo piston 11-40009-1 2 44

03/2614 DEF MI 1/09/2003 LTL Wanganui . The protective coating was removed from the main landing gear cylinder revealing corrosion between the rosette welded lower flange and the cylinder.

Leg cyclinder 08-40085-1 12 2 45

03/2846 DEF MI 11/09/2003 LTN Wanganui A undercarriage cylinder was found badly corroded. Leg Cylinder 08-40085-1 005 2 46

04/1229 DEF MI 5/04/2004 LTS Kaipara It was reported that whilst operating from a rough strip the RH main undercarriage torque link lower bolt head sheared off.

Torque link lower bolt

NAS1307-780

2 47

04/1393 DEF MI 19/04/2004 LTY Taumarunui It was reported that whilst operating from a rough strip the right main undercarriage torque link lower bolt head sheared off.

Torque link lower bolts

NAS1307-78D

2 48



UTCReg Location


04/3232 DEF MI 6/10/2004 LTS Wanganui The aircraft's nose landing gear steering pin was found cracked during a 500 hour inspection.

Steering Pin 08-45711-1 2 49

05/351 DEF MI 26/01/2005 LTH Wanganui A crack was found in the main landing gear axle during a 500 hour magniflux crack inspection.

Axle 08-40021-1 LTS-8 2 50

05/353 DEF MI 26/01/2005 LTL Wanganui A crack was found in the main landing gear axle during a 500 hour magniflux crack inspection.

Axle 08-40021-1 LTY-1 2 51

05/686 DEF MI 1/03/2005 LTA Gisborne It was reported that the aircraft was found to have an MLG Cylinder broken adjacent to the LWR mounting Clamp.

MLG Cylinder 2 52

05/817 DEF MI 16/03/2005 LTX Napier It was reported that the undercarriage piston was found to be bent and approximately 7/16 inches over its length.

Piston 2 53

05/1341 DEF MI 4/04/2005 LTY Wanganui During a 500 hour inspection of a Cresco aircraft the Axle 08 40021 1 2 54


05/1341 DEF MI 4/04/2005 LTY Wanganui During a 500 hour inspection of a Cresco aircraft the main landing dear axle was found cracked.

Axle 08-40021-1 2 54

05/1340 DEF MI 18/04/2005 LTL Wanganui The lower torque link bolt was found to be cracked during the 100 hour inspection.

Lower Torque Link Bolts

NAS 1307 - 78D

2 55

05/1579 DEF MI 16/05/2005 LTL Wanganui The main landing gear lower torque link bolt was found cracked during the 100 hour inspection.

Lower Torque Link Bolts

NAS 1307 - 78D

2 56

05/1580 DEF MI 16/05/2005 LTL Wanganui The nose wheel steering pin was found cracked during the 500 hour inspection.

Steering Pin 08-45711-1 2 57

05/1881 DEF MI 27/05/2005 LTX Napier The Cresco aircraft axles were found to be cracked. Axle 08-40021-1 2 58

05/2118 DEF MI 23/06/2005 LTY Wanagnui During the 100 hour inspection the nose undercarriage cylinder was found cracked at the lower flange.

Nose Landing Gear cylinder

08 - 40085 - 1

157 2 59

05/4394 DEF MI 24/11/2005 LTH Wanganui During a 500 hour magniflux inspection the NLG steering pin was fond to be cracked.

Steering Pin 08-45711-1 2 60

05/4393 DEF MI 19/12/2005 LTY Wanganui During a 500 hour magniflux inspection the axle was found to be cracked.

Axle 08-40021-1 LTV-5 2 61



UTCReg Location


05/4392 DEF MI 22/12/2005 LTV Wanganui During a 500 hour magniflux inspection the MLG axle was found to be cracked.

Axle 08-40021-1 LTZ-3 2 62

05/4317 DEF MI 23/12/2005 TMM Tiroa Taumaranui Aerial Co-Operative reported that the starboard wing was noticed to be lower than normal during the take off roll during the 11th load of the day. It was found that the undercarriage leg had partially collapsed.

Undercarriage Leg

08-600 037 2 63

06/1165 DEF MI 2/03/2006 LTS Wanagui During a 500 hour NDT inspection a MLG axle was found to be cracked.

Axle 08-40021-1 LTH-2 2 64

06/2004 DEF MI 4/04/2006 LTN Wanganui During a 500 hour magniflux inspection a MLG axle was found to be cracked.

Axle 08-40021-1 LTN1 2 65

06/4496 DEF MI 20/11/2006 LTZ Hunterville The aircraft taxied forward away from the loader, Propeller HC-B3TN-3D BNA260 2 66


06/4496 DEF MI 20/11/2006 LTZ Hunterville The aircraft taxied forward away from the loader, when the nose wheel ran through soft gravel with the propeller striking a large stone in the soft ground.

Propeller HC B3TN 3D BNA26013

2 66

07/2448 INC MI 7/07/2007 LTL Wanganui The pilot commenced a takeoff on a sowing run and as the aircraft was rotating a thud was heard on the L/H main undercarriage. The view through the hopper mirror revealed the L/H main undercarriage was hanging there and damage to the L/H flap. The load wa s spread and the aircraft flew to Wanganui Airport where a landing was made with emergency services on standby.�Investigation revealed the aircraft had hit a lamb on takeoff and the impact had caused the L/H main landing gear attachment bolts to shear off. This allowed the main leg to contact the flap causing the damage.�A warning has been sent out to all pilots on the use of airstrips with stock around.

2 67



UTCReg Location


98/3773 DEF MA 11/12/1998 TMO HAWKES BAY During take off the engine suffered significant power loss, to avoid obstacles the load was dumped and avoidance action taken. The aircraft landed without any damage.

bleed valve diaphram

3100829-03 20A324 4 1

99/304 DEF MI 3/02/1999 LTV NAPIER Crack found on routine maintenance. Indication of crack: paint split and exuding inhibitor fluid.

LH & TOP ENGINE MOUNT BOLT ATT

4 4 2

99/305 DEF MI 3/02/1999 TMO NAPIER Crack found on routine maintenance. Indication of crack: paint split and exuding inhibitor fluid.

LH ENGINE MOUNT BOLT ATTACHMEN

3 4 3

99/306 DEF MI 3/02/1999 TMN NAPIER Crack found on routine maintenance. Indication of crack: paint split and exuding inhibitor fluid.

LH ENGINE MOUNT BOLT ATTACHMEN

1 4 4

99/2094 DEF MI 31/05/1999 TMO NAPIER On routine maintenance, the engine mount was Engine Mount 4 5


99/ 094 F MI 3 /05/ 999 TMO NAPI R On routine maintenance, the engine mount wasfound to have a crack at the centre isolator attachment bolt bushing.

ngine Mount 4 5

99/1893 DEF MI 22/06/1999 TMN NAPIER On routine inspection (100 hour) a crack was detected in the engine mount at the left hand side isolator attachment cluster.

Engine Mount 08-57017-1 4 6

99/3693 DEF MA 23/12/1999 TMM HAMILTON The pilot reported that the right hand lower engine mount attachment was cracked at the weld. A new part was fitted and PAC have the old one for analysis.

Engine mount 243665-4R 4 7

00/1005 DEF MI 16/03/2000 WAT NAPIER During routine maintenance the lower right hand engine mount bracket was found cracked.

Engine Mount 24 3665-4R 4 8

00/1641 DEF MI 3/05/2000 LTU GISBORNE During routine maintenance the right hand bracket was found with a crack adjacent to weld along the full length of the weld. The fire wall was cracked just below right hand lower engine mount tube attachment at the rear.

BRACKET 24366654R 4 9



UTCReg Location


00/1644 DEF MI 4/05/2000 LTX GISBORNE During routine maintenance the right hand bracket was found with a crack adjacent to weld along the full length of lower side weld.

BRACKET 2436654R 4 10

00/1829 DEF MA 29/05/2000 LTY WANGANUI During 100 hour inspection the righthand lower engine mount was found broken off.

RH lower mount bracket

08100941 4 11

00/2179 DEF MA 30/05/2000 LTZ WANGANUI Engine mount righthand fuselage bracket forward face cracked.

RH lower engine mount bracket

08100941 4 12

01/4075 DEF MI 27/11/2001 LTV Wanganui The right lower A/F engine mount bracket was broken off.

A/F engine mount

4 13

02/1538 DEF MI 9/05/2002 LTY Wanganui The right lower airframe engine mount bracket had broken off.

mount bracket 4 14


broken off.

03/244 DEF MI 14/01/2003 LTZ Wanganui Engine Bracked Mount (right/hand lower A/F) found cracked.

R/H Lower A/F Engine Bracket

08-10094-1 4 15

04/852 DEF MI 3/03/2004 LTA Napier It was reported that the aircon compressor mount bracket was found fractured in two.

Compressor Mount Bracket

08-74285-1 NSN 4 16

04/1483 DEF MA 29/04/2004 LTE Napier During topdressing operations in flight the pilot heard a loud "crack" sounding like a rifle shot. The aircrafts engine was noticed to have slightly displaced. An engineering inspection revealed the LH engine mount strut was found broken adjacent to the f orward attach bolt fitting. The left hand side longeron was also found cracked at the strut attachment.

Engine mount strut

08-10271-2 4 17



UTCReg Location


04/1483 DEF MA 29/04/2004 LTE Napier During topdressing operations in flight the pilot heard a loud "crack" sounding like a rifle shot. The aircrafts engine was noticed to have slightly displaced. An engineering inspection revealed the LH engine mount strut was found broken adjacent to the f orward attach bolt fitting. The left hand side longeron was also found cracked at the strut attachment

Engine mount strut

08-10271-2 4 18

04/1581 DEF MA 3/05/2004 JOF Napier It was reported that the top left bolt attaching the engine mount frame to the engine mount strut broke through the treaded area at the base of the nut.

Attach Bolt AN6-54A 4 19

04/1967 DEF MA 13/06/2004 LTA Gisborne During the take-off roll, a loud bang was heard and the aircraft aborted the take-off. The left engine mount strut was found fractured and the longeron

Strut/longeron 08-10271-3 NSN 4 20


mount strut was found fractured and the longeroncracked.

04/2141 DEF MI 17/06/2004 LTT Napier The inspection as per the ADand SB revealed cracking of the longeron at the 1/4 inch bolt location on the engine mount strut.

Longeron 243019-3L 4 21

04/2144 DEF MI 17/06/2004 LTU Napier An inspection as per the ADand SB revealed a cracked longeron at the 1/4 inch bolt hole location on the engine mount strut.

Longeron 243019-3L 4 22

04/2139 DEF MI 20/06/2004 WAT Napier An inspection of the engine mount strut and associated longeron revealed cracking of the longeron through the1/4 inch rear bolt hole strut attachment

Longeron 243019-3L NSN 4 23

04/2140 DEF MI 25/06/2004 WAT Napier The left hand strut was removed for inspection as per the SB and AD.The engine mount attachment bolt AN6-54A was found bent in the engine mount strut, predominantly toward the treaded end.

Strut 08-10271-3 4 24



UTCReg Location


04/2145 DEF MI 25/06/2004 LTU Napier During compliance with the AD and SB a crack was found in the strut at the known fracture area. This is the interface of the engine mount attachment bolt tube and the main tube, through the weld.

Strut 08-10271-2 4 25

04/4180 DEF MI 23/12/2004 LTX Napier It was reported that the strut failed at the welded junction between the tube section and rear foot assembly.

Engine Strut Assy L/H

08 10271 3 4 26

05/3739 DEF MI 14/11/2005 LTQ Hamilton Super Air reported that the engine mount P/N 08-51071-1 was found to be cracked at the cluster formed at tubes adjacent to the engines lower pickup attachments.

Engine Mount 08-51071-1 005 4 27

06/119 DEF MA 22/01/2006 LTE Anaura Bay The aircraft was carrying out agricultural operations Engine mount AN6-60A 4 28


y y g g pwhen a loud noise was heard. The pilot made a precautionary landing on a nearby beach. It was discovered that the top L/H engine mount to firewall attachment bolt had broken, causing substantial dama ge to the engine mount frame.

gto firewall bolt

06/2975 DEF MI 26/07/2006 LTC Wanagaui During a 200 hour dye penetrant inspection of the engine mount struts the LH engine mount strut was found to be badly cracked.

Engine Mount strut

08-10272-4 4 29

79/41 ACC MA 27/02/1979 LTP NR CAMBRIDGE

A complete loss of engine power occurred during the aircraft's maiden flight. in the course of the ensuing forced landing it passed through three fences. the design of the main fuel filter mounting and drain line caused a failure of the fuel line through propagation of a fatigue crack.

79-039 5 1



UTCReg Location


80/145 ACC MA 30/12/1980 LTQ NR OHURA

Aircraft engine flamed out seconds after pilot completed reversal turn at end of sowing run. during ensuing forced landing undercarriage collapsed when aircraft ran across drain. major damage to fuselage confined to structure forward of firewall. cockpit structure intact. subsequent investigation indicated engine flamed out due to ingestion of air through fuel selector valve

80-144 5 2

94/535 DEF MI 7/02/1994 LTP HAMILTON COMPRESSOR 5 3

98/1863 DEF MA 26/02/1998 LTQ MALAYSIA The main oil cooler line ruptured, fortunately while the aircraft was on the ground. The pilot shut the engine down.

OIL COOLER LINE

5 4

00/2605 DEF MI 19/07/2000 TMO NAPIER During routine maintenance a small section of metal was found on top of the rear combustor drain when

large exit duct 310926302 5 5


was found on top of the rear combustor drain when it was removed.

01/2983 DEF MI 13/06/2001 LTX Gisborne Failure of rear bearing of air conditioning drive pad seal, filled cavitiy between seal & drive pad 08-74281-1 migrated down drive spline, around and through rear bearing, washing grease from bearing leading to failure. Pacific Aerospace (John Garwood let ter 21/06/2001) have investigated at length and is assessing modifications to achieve a resolution. Apparently this is not the first such problem with ZK-LTX.

Drive assembly bearing

6005-2RS NSN 5 6

01/2374 DEF MI 17/06/2001 LTX Gisborne Engine air conditioning drive pulley failed. Air con drive 5 7

02/844 DEF MI 27/02/2002 LTE Hawke's Bay During flight the Airconditioning system failed. Drive adapter pulley assembly

5 8



UTCReg Location


03/780 DEF MA 13/03/2003 LTY Wanganui The engine would not accelerate from ground idle because the P3 airhose was U/S.

P3 air hose 3026687 5 9

03/1990 DEF MI 30/06/2003 LTA Napier During an inspection several cracks were found around the bolt holes of the exhaust duct outlet flange. This same defect has been noticed before on other Cresco aircraft.

Exhaust duct flange

3111780-01 in098 5 10

03/2004 DEF MI 2/07/2003 LTT Napier During a hot section inspection the B.O.V. diaphragm was found to be chaffed through in two places and the bleed valve was not closing completely.

Bleed valve diaphram

3103347-01 5 11

03/3596 DEF MI 9/11/2003 LTE Napier During flight operations the operator observed the RH exhaust stack panting.�

Exhaust Stack 08-51087-1 5 12

03/3911 DEF MA 19/12/2003 LTC Wanganui It was reported that the aircraft lost power Fuel Control 3049635-02 C22346 5 13


/ / / g p pdramatically on two successive take offs. Unit

93/1238 ACC MA 12/03/1993 LTQ 3 S Omarama Wind gust, aircraft left strip 7 1

94/327 INC MI 3/02/1994 LTS NGAMATEA STATION APPROACHED AIRSTRIP TO COMMENCE DAYS TOPDRESSING, ON APPROACH AIRCRAFT SPEED SLOWED, HEAVY LANDING

7 2

96/2714 ACC MA 10/10/1996 LTR 20 NE WanganuiAircraft suffered damage to prop and fuselage while landing on wet grass.

Cam follower 7 3

97/3003 ACC MI 2/10/1997 JAD Malaysia

ZK-JAD in Malaysia has had a motor cyclist ride out in front of the aircraft on take off. The propeller struck the motor cyclist who died as a result of the injuries.

7 4

00/4250 ACC MI 18/12/2000 LTS Te Wera

While turning In a confined loading area the right wheel entered a hollow caused the aircraft to drop which allowed the starboard flap to catch on a fence post, damaging the flap. The Operator reported that the confined area and ground erosion, after heav y rain, were factors.

STARBOARD FLAP

7 5



UTCReg Location


01/1966 ACC CR 6/06/2001 LTT Wairoa

While ZK-LTT was engaged in aerial topdressing operations the low pressure "fuel" light illuminated followed shortly by a flameout. The pilot attempted a relight but due to the low height the aircraft was secured for a precautionary landing; the landing was made on a soft, uphill slope. The pilot stated that it was apparent that low fuel quantity may have contributed to the flameout. The pilot escaped from the substantially damaged aircraft safely.

7 6

01/2182 ACC MA 26/06/2001 PWT Weber

This aircraft was coming into land at Ora Station airstrip and just before it touched down the aircraft encountered a strong 'down-draft' which resulted in a heavy landing.

7 7


02/1158 INC MI 17/02/2002 PDZ Jardines The pilot made several low passes to clear sheep and then had to re-circuit because of a wind change. On that approach he encountered wind shear and turbulence that caused the aircraft to lose height and the right wing tip to scrape the ground. A go aroun d was made and a safe landing made next time. Only minor wing tip damage was caused.

7 8

02/1366 ACC MA 2/05/2002 LTS Piopio

The aeroplane was on a normal approach to the airstrip, and with a tailwind of 8 - 10 knots, the pilot was aiming to touch down in the first quarter of the strip.�The right mainwheel clipped the threshold of the strip and broke off. The aeroplane slid u p the strip and collided with an embankment.

7 9



UTCReg Location


02/3386 INC MI 2/11/2002 PKB East Otago The aircraft was landing in know gusty tailwind conditions and was caught in a downdraught, which resulted in a heavy landing.

7 10

03/3619 INC MI 7/12/2003 TTS Taupo It is reported that the aircraft (ZK-TTS) took off on rwy17 while ZK-EAI was on short finals. The pilot of EAI carried out a go-around due to TTS being on rw17 while EAI was on final for rwy17.

7 11

04/2151 INC MI 24/05/2004 LTZ R. Louries Airstrip It was reported that the loader struck the aircraft damaging the starboard flap. The loaders brakes failed due to a failure of the brake pedal unit in the rear cab.

Right Hand Flap

7 12

04/2352 INC MA 26/07/2004 LTY Te Kuiti The pilot was trying to land after dark on an unlit airfield and with his landing light deliberately

it h d ff (d t l ll ) E

7 13


switched off (due to glare on propeller). Even though he was familiar with the field he became disoriented and flew away from above the runway and landed on the racecourse back straight boundary fence

05/197 DEF MI 28/01/2005 LTG Gisborne Airways reported that ZK-LTG was an arriving VFR flight at NZGS. The flight landed on RWY14 and rolled clear before the pilot reported a punctured tyre. The flight shut down at the drain adjacent to Farmers Air and clear of the main runway for approximate ly forty minutes while the puncture was repaired. No other aircraft were affected.

Tyre 7 14

07/1005 INC MA 27/03/2007 LTZ Te Hekenga Stn The pilot and loader driver got out of the aircraft to inspect loader for mechanical defect. The aircraft rolled backwards off side of strip and down steep hillside. The park brake was not applied.

7 15



UTCReg Location


01/2140 DEF MA 19/06/2001 PDZ Queenstown The pilot made a Mayday call because of a rough running engine. He was given a clearance to use the runway of his choice and he landed safely on runway 23. The Cresco had to be towed clear once it had stopped.

Beta Rigging 8 1

01/2053 ACC CR 13/06/2001 TMO 17 W Gisborne

Significant event. The Cresco aircraft had just taken off from the airstrip and initiated a dump during a steep left turn in order to remain clear of the surrounding terrain. However, the aircraft continued to lose altitude and there was insufficient he ight remaining to recover the situation. The aircraft subsequently struck the ground and a fence post then cartwheeled across a road and caught fire. The aircraft was destroyed and the pilot was killed in the accident.

9 1


accident.

02/896 ACC MA 27/03/2002 LTV nr Taihape

The Cresco had been operating off the strip for about two and a half hours, and was on its fifth flight since refuelling. It became airborne at the same point as on previous takeoffs, but shortly after takeoff, encountered "sink". The pilot was unable t o prevent the aeroplane colliding with the fence at the end of the strip and touching down in the next paddock. He applied reverse thrust which reduced the effects of subsequent collisions with further fences and a set of cattle yards.�Conditions had been calm up to the time of the accident, and the pilot was certain that there was no power loss.

9 2



UTCReg Location


93/4118 DEF MI 9/09/1993 LTS HAMILTON AUXILEC STARTER/GENERATOR

524-010 234 10 1

99/1281 DEF MI 26/04/1999 LTX HAWKES BAY DC generating system voltage increased to GCU trip voltage.

Circuit breaker 10 2

03/1341 DEF MI 25/04/2003 LTY Wanganui An electrical wire from the no1 relay to the GCU circuit breaker burnt out, filling the cockpit with smoke.

GCU Electrical Wire

10 3

04/1580 DEF MA 30/03/2004 JOF Napier While carrying agricultural operations an electrical burning smell was evident and smoke emitted from the instrument panel.

Gen field wire 10 4

04/2125 DEF MI 28/06/2004 JOF Napier The pilot noticed that the discharge light illuminated, low pressure fuel light illuminate on take off The voltage of the batteries was found to be at 22 Volts DC and there had been a hot start.

Connector Wiring

MS3126E-14-125

NSN 10 5


79/150 ACC MA 10/12/1979 LTP NR MARAMARUA

While engaged in certification test flying the pilot of the prototype cresco aircraft encountered speed control difficulties which were immediately followed by in flight structural failures. the pilot baled out and the aircraft descended out of control and exploded upon ground impact.

79-146 11 1

93/3844 DEF MA 29/07/1993 LTS WANGANUI ELEVATOR MOUNTING DRAG ANGLES

08-11229-1 AND 08-1

11 2

93/3863 DEF MA 29/07/1993 LTS FLAP CABLE CAB-F-61-91 11 3

93/3668 DEF MA 11/08/1993 LTP NAPIER POWER LEVER CONTROL CABLE

CAB-3-1 11 4

93/4006 DEF MI 20/08/1993 TMN HORIZONTAL STABILISER ATTACHME

AH4H-7A 11 5



UTCReg Location


94/610 DEF MA 16/02/1994 LTR WANGANUI ENGINE CONTROL CABLE

19162400225

11 6

94/1916 DEF MI 10/04/1994 LTR WANGANUI CABLE CAB-1-61-91-1196

11 7

94/1716 ACC MI 18/04/1994 JAD Te AkauCanopy detached during turbulence CANOPY-

STABILISER243300-2. 08-32001-2

11 8

94/1716 DEF MI 18/04/1994 JAD Te Akau Canopy detached during turbulence CANOPY-STABILISER

243300-2. 08-32001-2

11 9

94/2335 DEF MI 9/05/1994 LTS WANGANUI CABLE 11 10

94/3946 DEF MI 19/09/1994 LTS WANGANUI CABLE CAB-F-61-91-1196

11 11

94/3947 DEF MI 19/09/1994 LTS WANGANUI STEERING POST

08-45661-3 11 12

94/3951 DEF MI 19/09/1994 LTS WANGANUI ELEVATOR CAB-P-14-83- 11 13


CONTROL SYSTEM

2900

94/3953 DEF MI 19/09/1994 LTS WANGANUI ELEVATOR CONTROL CABLE

P-N-14-83-2929

11 14

94/4425 DEF MI 9/11/1994 LTS WANGANUI FLAP CONTROL SYSTEM CABLE CAB-F-61-91-1196

11 15

94/4424 DEF MI 24/11/1994 LTS WANGANUI FLAP CONTROL SYSTEM CABLE CAB-F-61-91-1196

11 16

94/4488 DEF MI 27/11/1994 LTP NAPIER RUDDER HINGE CRACKED ALONG SIDE FLANGES. BOTH SIDES HAD HALF INCH CRACKS.

HINGE 08-32037-1 11 17

96/337 DEF MA 7/02/1996 LTT NAPIER Rudder control cable p/n CAB-D-82-14-3262 MAS. Right Hand

Rudder cable CAB-D-82-14-3262MAS

11 18

96/430 ACC CR 22/02/1996 JAD MANGAKINOOn take off acft became uncontrollable. Major damage.

Bolt AN5-36A 11 19

96/954 DEF MA 13/03/1996 LTS WANGANUI Nosewheel steering. Link assembly 245235-2 11 20

96/952 DEF MA 19/03/1996 LTR WANGANUI Elevator Control Control cable CAB-P-83-2929

11 21



UTCReg Location


96/953 DEF MA 19/03/1996 LTR WANGANUI Elevator Control Cable CAB-P-14-83-2900

11 22

96/816 ACC CR 24/03/1996 TMO Wairoa

Whilst at rest on a farm strip with the engine running, the parking brakes failed and aircraft started running forward. Pilot made an immediate take off, during which the aircraft departed the strip, sustaining the loss of the LH main gear and related dam age. Once airborne aircraft routed to Wairoa and made an emergency, deadstick landing.

11 23

96/1668 DEF MA 17/04/1996 LTS WANGANUI Elevator Control Elevator cable CAB-P-14-83-2900

11 24

96/2633 DEF MA 19/08/1996 LTR WANGANUI Horizontal stabilizer P/N 08-3011-2 Hori stab 08-3011-2 11 25

97/1706 DEF MA 16/04/1997 LTV WANGANUI Elevator control cable inspected and broken strands found.

Elevator cable CAB-14-83-2900

11 26


97/1712 DEF MI 7/05/1997 LTS WANGANUI During a 500 hour inspection the elevator control on inspection was found to have broken strands.

Cables cab-d-14-83-2900

11 27

97/2214 DEF MA 10/07/1997 LTS WANGANUI Elevator control cable removed for 500hr inspection, broken strand found so a new cable was fitted.

elevator cable CAB-14-83-2900

11 28

97/3826 DEF MI 1/12/1997 LTQ MALAYSIA During normal 100 hour inspection corrosion of rivets was found in the elevator control system. Some rivets had corroded off.

ALLOY TUBE CORRODED

11 29

97/3827 DEF MI 1/12/1997 JAD MALAYSIA During normal 100 hour inspection corrosion of rivets was found in the elevator control system. Some rivets had corroded off.

ALLOY TUBE CORROSION

08-45079-1 11 30

97/3828 DEF MI 1/12/1997 LTW MALAYSIA During flight the trim function failed. Broken inner drive trim.

11 31

97/3829 DEF MI 1/12/1997 PNX MALAYSIA During flight the trim function failed. INNERDRIVE TRIM

11 32

97/3836 DEF MI 2/12/1997 PNX MALAYSIA During maintenance the top and bottom flap skin was split along the trailing edge.

Skin 241606 11 33



UTCReg Location


97/3837 DEF MI 2/12/1997 JAD MALAYSIA During maintenance the top and bottom flap skin was split along the trailing edge.

skins 241607 11 34

97/3838 DEF MI 2/12/1997 LTQ MALAYSIA During maintenance the top and bottom flap skin was split along the trailing edge.

skins 241607 11 35

97/3839 DEF MI 2/12/1997 LTW MALAYSIA During maintenance the top and bottom flap skin was split along the trailing edge.

skins 241606 11 36

00/429 DEF MA 17/02/2000 TMM TAUMARUNUI During his pre flight inspection the pilot noticed that the L/H aileron outer hinge attachment support steel gussot had broken. Engineering consulted the manufacturer and repaired it.

Aileron Hinge Attachment

241421 11 37

00/4494 DEF MI 27/03/2000 TMM Wanganui During inspection an elevator control cable was found to have broken strands sufficient to exceed serviceability limits.

Cable CAB-D-14-83-2906

11 38


01/1409 DEF MI 11/03/2001 LTV Wanganui ELevator contol cable found to have broken strands Elevator control cable

CAB-P-14-83-2906

11 39

01/1407 DEF MI 13/03/2001 LTY Wanganui During 100 hour inspection elevator cable found to be us due broken strand.

Elevator cable 11 40

01/1632 DEF MA 6/04/2001 LTY Wanganui The elevator trim drive cable broke. Drive cable 08-45241-3 11 41

01/1802 DEF MI 1/05/2001 LTY Wanganui The flap control handle ratchet mount was cracked around a weld.

Flap handle 11 42

01/2390 DEF MI 17/06/2001 LTZ Wanganui Flap control handle ratchet mount tube P/N 08 45911-1 cracked around weld allowing ratchet quadrant to pull off.

Flap control ratchet mount

11 43

01/2390 DEF MI 17/06/2001 LTZ Wanganui Flap control handle ratchet mount tube P/N 08 45911-1 cracked around weld allowing ratchet quadrant to pull off.

Flap control ratchet mount

11 44

01/2211 DEF MI 20/06/2001 LTS Wanganui During maintenance the elevator cable was replaced because it was found to have several broken strands on it.

11 45



UTCReg Location


01/3415 DEF MI 21/09/2001 WAT Napier The flap control cable was found damaged in several places and worn through 50% in other places, due to contacting various fasteners and structure.

Flap cable 11 46

01/3797 DEF MA 12/10/2001 LTS Wanganui During a 4 yearly inspection of the elevator control system the rear bell crank was found badly corroded and the mounting lug was cracked.

Rear elevator bell-crank.

11 47

02/419 DEF MI 12/01/2002 LTE Napier The operation of the elevator trim was found to be erratic and the tab travel was operating out of sequence.

Elevator and trim control

11 48

02/422 DEF MI 21/01/2002 LTE Napier The elevator trim would not work electrically or manually.

Elevator trim 11 49

02/848 DEF MI 28/02/2002 LTC Wanganui During an inspection the elevator control rear bell crank was found cracked and badly corroded i t ll

Rear bell crank mount

11 50


internally .

02/2634 DEF MI 18/08/2002 LTE Napier Pilot was unable to fly aircraft in a balanced condition - rudder control was stiff.

Push rod assembly

08-45653-1 11 51

02/3603 DEF MI 1/12/2002 LTH Wanganui Elevator lower control cable found un-serviceable. Elevator Control System

CAB-D-14-83-2906

11 52

03/833 DEF MI 4/03/2003 LTE Napier The flap control cable was found to have damaged wires in four locations. A new cable was fitted.

Flap cable CAB-F-36-90-0892

11 53

03/1618 DEF MI 19/05/2003 JOF Napier The electric elevator trim failed to operate in the up mode.

Trim relay MS25273-D1 11 54

03/2821 DEF MI 5/09/2003 LTE Napier Engineer reported that the aft cable link was found to be fitted at the Aft postion where another link (# 08-45027-1) would normally be fitted.

Link - Aft - Cable

08-45035-1 11 55

03/2969 DEF MI 2/10/2003 LTY Wanganui The aileron direct cables were found badly worn with some broken strands during a 4 yearly inspection.��

Aileron cables direct

CAB-D-83-34-1850

CAB-D-83-34-1850

11 56



UTCReg Location


03/3343 DEF MI 19/11/2003 LTY Wanganui The elevator lower control cable was found U/S due to broken strands. ��

Elevator control cable

CAB-D-14-83-2906

11 57

04/108 DEF MI 5/12/2003 LTS Wanganui The engineer reported that the aileron control cable was found very badly worn. The wear was mainly damaged strands.


11 58

03/3640 DEF MI 9/12/2003 LTL Wanganui The flap control handle ratchet mount tube found badly cracked. This is possibly due to the ratchet mount weld being overloaded.

Handle Ratchet Mount

08-45911-1 11 59

04/107 DEF MI 7/01/2004 LTC Wanganui The engineer reported that the aileron control cables were found very badly worn. The wear consisted of mainly damaged strands.


CAB-D-83-34-1850

11 60


04/488 DEF MI 5/02/2004 JOF Napier It was reported that the rudder rod end bearings were found very tight on the push rod. The attach bolts were found to be working causing the bolt to wear against steering post causing damage to the stearing post and bolts.

Rod end bearings

08-45653-1 11 61

04/754 DEF MI 25/02/2004 LTN Unknown It was reported that the bolts retaining the control column in the quadrant were found to have not been fitted since new. The bolt holes were full of paint.

Control Column

08-45031-1 11 62

04/717 DEF MA 1/03/2004 LTX Napier It was reported that during compliance with AD DCA/CRESCO/06 on aileron cables, it was found that the balance cables were worn to limits at fairlead locations throughout wing with major wear was at the root location.

Cables, balance

242671/72 11 63

04/1643 DEF MA 12/04/2004 WAT Christchurch It was reported that the aileron balance cables were found worn at the fairlead locations. The direct cables were found statisfactory.

Balance Cables 242672/242671

11 64



UTCReg Location


04/2764 DEF MI 27/08/2004 EEL Taieri It was reported that the aircraft's cross tube assembly was severely corroded internally.

Cross Tube Assy

11 65

04/2904 DEF MI 9/09/2004 LTY Wanaganui It was reported that during a 4 yearly airframe inspection, an aileron cable was found badly worn. It was only 576 hours since it was new.

Aileron Cable 11 66

05/664 DEF MI 11/01/2005 JOF Napier It was reported that the elevator trim was found to be inoperative.

Trim 11 67

05/1348 DEF MI 18/01/2005 LTH Wanganui Whilst carrying out a 700 hour inspection an elevator control cable was found unserviceable.

Elevator Control Cable

CAB-P-83-2935

11 68

05/268 DEF MI 21/01/2005 LTE Napier During routine inspection both left and right aileron control cables were found worn at the centre wing fairleads. The cable wear up to 50% of the strand with some broken wires evident on both cables.

Aileron Control Cables

CAB-D-83-34-1850

11 69


with some broken wires evident on both cables.

05/2521 DEF MI 28/02/2005 TML Hamilton The pilot reported that the flap handle was bending during operations.

Flap Handle 08-4-5919-1 11 70

05/818 DEF MI 11/03/2005 LTU Napier It was reported that ZK-LTU left hand rudder pedal inputs failed during landing.

Rod end 11 71

05/1339 DEF MI 18/04/2005 LTH Wanganui Whilst carrying out a 700 hour inspection of the elevator control cable it was found broken.


11 72

05/1414 DEF MI 19/04/2005 NZO Queenstown It was reported that the predrilled holes in the elevator trim tab were too close to the hinge.

Elevator Trim Tab Hinge

09-31209-2 11 73

05/1413 DEF MI 26/04/2005 NZO Queenstown New aileron hinges arrived from the aircraft manufacturer for a Cresco aircraft with pivot holes drilled to 5/32" they should have been 3/16" in diameter.

Aileron Hinges 241546-1 11 74

05/1449 DEF MI 3/05/2005 LTN Wanganui During a 700 hour inspection the elevator control cables they were found unserviceable..


CAB-P-14-83-2906

11 75



UTCReg Location


05/1867 DEF MI 23/05/2005 LTL Wanganui During an inspection the aileron cables P/N 242672 and CAB-D-83-34-1850 were found to be unserviceable.

Aileron Cable 242672 11 76

05/2289 DEF MI 14/06/2005 LTH Wanganui During compliance with AD DCA/CRESCO/6 the aileron control cables was found unserviceable.


242672 11 77

05/2948 DEF MI 23/08/2005 LTX Napier During scheduled maintenance the doubler strap on the flap push pull rod torque tube attachment was found to be cracked.

Flap torque tube

08-04225-1 11 78

05/3369 DEF MI 3/10/2005 LTG Napier The right hand aileron push rod, aft rod end fitting attachment rivets were found to be loose in the tube although tight in the fitting.

Aileron push rod

08-24015-1 11 79

06/387 DEF MI 27/01/2006 LTQ Te Kuiti An agricultural operator reported that the aileron Aileron Fairing 08-24112-1 11 80


fibre glass tip came loose and parted from the aircraft during the flight.

06/1166 DEF MI 20/03/2006 LTY Wanganui During an inspection of the aileron cables inaccordance with AD DCA/CRESCO/6 aileron cables P/N 242671, 242672 and D-83-34-1850 were found to be badly worn with broken strands.

Aileron Cable 242671/242672/

11 81

06/1168 DEF MI 22/03/2006 LTV Wanganui During an inspection of the aileron cables inaccordance with AD DCA/CRESCO/6 aileron cables P/N 242671, 242672 and D-83-34-1850 were found to be badly worn with broken strands.�


242671/242672

11 82

06/1167 DEF MI 24/03/2006 LTZ Wanganui During an inspection of the aileron cables inaccordance with AD DCA/CRESCO/6 aileron cables P/N 242671, 242672 and D-83-34-1850 were found to be badly worn with broken strands.�


242671/242672

11 83



UTCReg Location


06/1626 DEF MI 24/04/2006 LTT Taupo During agricultural operations the pilot lost use of his elevator trim.

Trim Indicator Shaft

11 84

06/2483 DEF MI 7/06/2006 LTL Wanaganui When complying with AD DCA/CRESCO/6 aileron cables P/N 242071, 2422072 and CAB - D - 83 - 34 - 1850 were found worn with broken strands.


242071/242072

11 85

06/4632 DEF MI 3/12/2006 WAT Napier The pilot had reported that the right hand brake pedal was not fully returning after the brakes had been applied.

Brake Master Cylinder

10-51A 11 86

07/822 DEF MI 9/03/2007 LTK Wanganui During an AD inspection complying with DCA/Cresco/6 aileron cables P/N 242671, 242672 and CAB-D-83-34-1850 were all found with many strands broken.

Aileron cables 242671/242672

11 87

97/1707 DEF MI 16/04/1997 LTV WANGANUI Fuel system. Float came off L.H. rear fuel tank sender unit and chaffed itself into small pieces

Fuel tank sender unit

12 1


sender unit and chaffed itself into small pieces contaminating tank.

sender unit

02/1128 DEF MI 10/03/2002 LTX Napier The pilot noticed that the low fuel pressure and rear boost pump warning lights were on and that there was no inlet fuel pressure.

Aux FUel boost pump

12 2

02/3575 DEF MI 18/11/2002 LTT Napier 1. Red low pressure fuel light illuminated - Green rear pump Ops light still on. Emergency switch activated - Front pump on. Post refuel - rear pump CB tripped.��2. Rear pump failed to cease operating and Front pump failed to start up

Rear Aux Fuel Pump & Relay

08-57135-1 or 2C6-2

4AT2 12 1

04/595 INC MI 13/02/2004 TTS Taupo It was reported that white vapour was noticed trailing from the right side of the aircraft on departure. The aircraft was informed and returned for landing. A safe landing was made.�Nothing abnormal was found. The aircraft had been refuelled just before the flight and it was thought that some surplus fuel venting may have been seen.

12 2



UTCReg Location


04/1043 DEF MI 22/03/2004 NZO Queenstown A film, possible fine carbon dust, was found on the sides of the engine driven fuel pump inlet filter bowl.

Filter Bowl/Filter

AN6235-3A 12 3

05/2993 DEF MI 29/08/2005 LTT Napier During a scheduled inspection of Cresco aircraft the rear fuel pump was found to be seized and the brush holder melted.

Rear Fuel Pump

2C6-2 10AV5 12 4

07/2670 DEF MI 19/07/2007 TMM Hamilton During a routine maintenance inspection a fuel leak was noted coming from the sump tank.

Fuel Tank 08-57215-1 12 5

97/2772 DEF MI 8/09/1997 LTS WANGANUI Horizontal stabiliser main spar web cracked from right hand mounting bracket rivet holes.

MAIN SPAR WEB

08-30027-1 13 1

97/2773 DEF MA 8/09/1997 LTV WANGANUI Horizontal stabiliser main spar web cracked from left hand rear mounting bolt hole

MAIN SPAR WEB

08-30027-1 13 2

97/3824 DEF MA 1/12/1997 JAD MALYSIA During t/o the pilot could not move the elevator Tailplane/Elev 08-45079-1 13 3


back to neutral position because the elevator had been damaged by rocks thrown back from the wheels.

ator

97/3825 DEF MA 1/12/1997 LTQ MALAYSIA During t/o the pilot could not move the elevator back to neutral position because the elevator had been damaged by rocks thrown back from the wheels.

ELEVATOR/TAILPLANE

08-45079-1 13 4

97/3833 DEF MI 2/12/1997 LTW MALAYSIA The elevator pivot bolts were loose. Pivot bolts 13 5

97/3834 DEF MI 2/12/1997 JAD MALAYSIA �The elevator pivot bolts were loose.

PIVOT BOLT 13 6

97/3835 DEF MI 2/12/1997 LTQ MALAYSIA The elevator pivot bolts were loose. PIVOT BOLT 13 7

00/2517 DEF MI 30/07/2000 LTA GISBORNE During topdressing operations, pilot intuitively felt some problem with the elevator. Pilot inspected elevator and observed attachment looseness.

centre bearing assembly

13 8

00/4524 DEF MA 18/09/2000 LTY Wanganui Horizontal stabiliser RH mounting bolt badly corroded and broken off.

13 9



UTCReg Location


01/1755 DEF MI 23/04/2001 LTX Napier During routine maintenance it was noticed that the elevator tips attachment screws were loose in the spar area. Further investigation revealed cracking in two associated places.

front Spar & ribs

08-31137-1 13 10

01/1801 DEF MI 1/05/2001 LTA Hawkes Bay The elevator tip ribs were found cracked at the outer rear flange corners.

13 11

01/2391 DEF MI 17/06/2001 LTZ Wanganui Horizontal stabiliser LH mounting bolt badly corroded and possibly cracked.

NAS 6604-8 bolt

13 12

01/2938 DEF MI 4/07/2001 TMN Hamilton Left hand elevator outer rig found cracked top and bottom at spar attachment (08-31193-1).

Elevator outer rig

13 13

01/2993 DEF MI 16/08/2001 LTY Wanganui During 100 hour inspection rear mounted horizontal stabiliser bolts with 317 TTIS, in last 4 months, was found to be badly corroded.

Rear mounting bolts

NAS 6604-23 13 14


01/4061 DEF MI 25/09/2001 LTX Napier The elevator tension clip was found to be cracked. tension clip 13 15

01/3903 DEF MI 13/11/2001 TMN Hamilton A stone off the main wheel damaged the left lower outboard skin panel and trailing edge spar cap extension of the tailplane.

Skin & Spar cap

13 16

02/841 DEF MI 12/02/2002 LTY Wanganui The horizontal stabiliser main spar centre web was found cracked near a mounting bracket.

Horizontal stabiliser

13 17

02/1140 DEF MI 26/03/2002 LTZ Wanganui During maintenance a horizontal stabiliser rear mount bolt was found badly corroded after only 9 months (510 hrs) in service.

bolt 13 18

02/1475 DEF MA 23/04/2002 LTZ Wanganui During an inspection it was found that the elevator spar and outer rear rib were both badly cracked.

08-31193-1 / 08-31137-1

13 19

02/1536 DEF MI 8/05/2002 LTY Te Kuiti The outboard elevator tip fell off in flight because the outer rib was cracked.

Elevator end rib

13 20



UTCReg Location


02/1838 DEF MI 10/06/2002 LTE Napier Following similar faults in other Cresco's the elevator (GRP) fibreglass tips were both found cracked along with the right spar on one of them.

Elevator end rib

13 21

03/630 DEF MI 27/02/2003 LTN Wanganui The horizontal stabilizer rear mounting bolt corroded.

Tailplane mounting bolt

13 22

03/2884 DEF MA 27/08/2003 TMM Hamilton Excessive movement in the tailplane attachment during 100 hour inspection.

Brackets 08-11217-1 13 23

03/2970 DEF MA 9/10/2003 LTC Wanganui The spar top cap of the main spar in the horizontal stabiliser was found to have broken through. Stress corrosion during its life is suggested as a cause.��

main spar top cap.

08-30023-2 13 24

03/3533 DEF MA 1/12/2003 WAT Napier During inspection of horizontal stabilizer rear spar in Web 08 30027 1 13 25


03/3533 DEF MA 1/12/2003 WAT Napier During inspection of horizontal stabilizer rear spar in accordance with bulletin PAC SB/CR/032. Centre web found cracked.

Web 08-30027-1 13 25

03/3536 DEF MA 2/12/2003 WAT Napier Rear spar top cap part number08-30023-2 found cracked at Station 8 RHS.

Top spar cap 08 30011 4 020 13 26

05/2442 DEF MI 8/07/2005 LTX Napier The Cresco horizontal stabilizer rear spar attach bolt was found to be broken in two places.

Stabilizer attach bolt

NAS6604-23 13 27

97/944 DEF MA 14/03/1997 TMN HAMILTON Pilot reported a fuel leak. Fuel was leaking from port leading edge tank during flight.

RIB 08-20071-1 14 1

99/770 DEF MI 15/02/1999 TMM Hamilton LH wing outer panel rear spar fitting found worn during inspection.

fitting 08-20143-1 14 2

99/3611 DEF MA 11/10/1999 LTT NAPIER Cracking found in wing outer panel. Wing Outer Panel

08-21101-1 14 3

99/3612 DEF MA 5/12/1999 LTU NAPIER Cracking found on the left hand wing outer panel. (See also WR 0/SAI/905).

Left hand Wing Outer Panel

08-21101-1 014 (aircraft)

14 4

99/3613 DEF MA 5/12/1999 TMO NAPIER Cracking found in right hand wing outer panel. (See also WR 0/SAI/905).

Right hand wing outer panel

08-21102-1 012 14 5



UTCReg Location


99/3614 DEF MA 5/12/1999 PWT NAPIER Cracking found in left wing outer panel. (See also WR 0/SAI/905).

Left hand wing outer panel

08-21101-1 010 14 6

00/3838 DEF MI 22/11/2000 LTA Hamilton During centre wing spar change the outer sections of web were found crcked. Cracks were extending from attachment rivets to outer edges and also down the flutes. Some crack up to 3/4" long at the flutes.

Web Outer Sections

0820023-1/0820024-1

14 7

00/4288 DEF MI 21/12/2000 TMN Taumarunui Pilot reported fuel leak investigation found lh leading edge tank outboard rib cracked crack located in radius of flange forward bottom approx 2" long repaired by back to back angle section.

Rib 08-20071-1 14 8

02/2262 DEF MI 18/07/2002 WAT Napier The front fuel tank had an excessive leak that was traced to area of the spar web near the upper cap. S l i t f d l i th t ith

Fuel Tank 14 9


Several rivets were found loose in that area with other showing signs of impending looseness.

03/1772 DEF MA 18/06/2003 PWT North Island There have been a few unreported cases of structural damage to Cresco aircraft. ZK PWT has suffered severe wing deformation.

Wing 14 10

03/2366 DEF MI 26/06/2003 WAT Napier During an inspection of the spar web on the left hand wing outer panel it was found to have a cracked flute first from the inboard end.

wing outer panel Spar Web

08-21101-1 019 14 11

03/2423 DEF MI 12/08/2003 LTA Napier During an inspection the front fuel tank baffle ribs were found cracked from the transfer holes of all the baffles.

Wing tank ribs 08-20073-1, -2, -3

14 12

03/3161 DEF MI 12/10/2003 LTE Napier The spar web was found cracked at the inboard flute of the outer wing panel. It was thought this was due to fatigue.

Spar web 08-21102-2 033 14 13

03/3342 DEF MI 17/11/2003 LTX Napier The right hand forward wing attachment bolt head was found sheared off. This was possibily due to a previous fence strike.

Wing attach bolt

ANS-24A 14 14



UTCReg Location


04/1484 DEF MA 29/04/2004 LTU Napier It was reported that the rear spar outer panel attachment fitting on the centre wing was cracked at the bolt hole.

Outer panel attach fitting

08-20143-1 14 15

05/2333 DEF MI 14/07/2005 LTU Napier The Cresco aircraft was found to have a stress band cracked at the out board ends.

Belly Stress Band

08-10193-2 14 16

05/2332 DEF MI 15/07/2005 LTX Napier During an inspection of the Cresco aircraft the outboard .leading edge rib of the right hand fuel tank was found t cracked at the upper camber flange and the outboard leading edge fuel tank baffle was cracked at the lightning hole.

Fuel tank LE Ribs

14 17

05/3478 DEF MI 19/10/2005 LTA N i Th i l di d ib f d t b k d Wi ib 08 20072 2 14 18


05/3478 DEF MI 19/10/2005 LTA Napier The wing leading edge rib was found to be cracked in five places at the leading edge skin attachment flange. This rib is also the fuel tank outboard rib.

Wing rib 08-20072-2 14 18

05/4391 DEF MI 10/11/2005 LTT Napier During a periodic inspection corrosion was found at the left hand outboard flap hanger. Upon further inspection externally and internally, extensive corrosion found internally throughout the centre wing.

Centre wing components

Wing 032

14 19

07/2426 DEF MI 15/06/2007 LTE Napier Working rivets were found on the left hand wing spar cap from BL 26.5 to BL 64 and the main landing gear rib at the attachment to the main spar. These rivets go through into the forward fuel tank and have become loose allowing fuel from the forward tank t o seep through into the wing.

Wing spar rivets

14 20



UTCReg Location


99/1421 DEF MA 3/05/1999 TMM HAMILTON During routine inspection a 3/4 inch crack was found in the angle capping. The crack was on the left hand side of the aircraft and initiated at a radius, extending the aircraft. A double repair was carried out with the manufacturers approval. This is t he first and only such defect.

ANGLE CAPPING

08-100161-1 15 1

00/418 DEF MI 7/02/2000 LTY NAPIER Fertiliser leaking in to the Cargo compartment was traced to a vertical crack in the rear hopper panel. It has since been repaired.

Fertiliser Hopper

15 2

00/3445 DEF MA 27/10/2000 LTA GISBORNE The hopper outlet control system failed during operations.

Lever Handle assembly

08-48043-1 NSN 15 3

01/1745 DEF MI 30/04/2001 LTA Gisborne The hopper handle assembly cracked at the cross Hopper 15 4


/ / / pp yshaft connection on both sides. This type of failure has occurred before a multitude of times on Cresco's.

ppHandle

02/1841 DEF MI 10/06/2002 LTE Napier During maintenance cracks were found in the left fuselage angle capping.

08-10161-1 Angle capping

15 5

03/3164 DEF MI 28/10/2003 PDZ Queenstown A 10" crack was found in the fuselage skin just aft of the skydiving door. It is suspected that skydivers pressing against the skin prior to jumping are pressing on the skin in this area.

Skin 15 6

03/3344 DEF MI 16/11/2003 LTX Napier During a scheduled inspection and with the hopper removed the stress bands were found cracked out board of the longerons.

Longeron stress band

08-10193-2 15 7

03/3349 DEF MI 16/11/2003 LTX Napier Both longerons were found cracked on the bend radius between Stations 115.34 and 118.84.

Longerons 08-11021-2 08-11

15 8



UTCReg Location


04/486 DEF CR 5/01/2004 NZO Queenstown During parachute operations of the Cresco aircraft the parachute door came off its tracks. The door was restrained only by drive strap jamming against rear support..

Parachute Door attachment

15 9

04/487 DEF MI 20/01/2004 LTU Napier It was reported that the fuselage rear frame P/N 08-11125-2 and frame bracket were found cracked when the horizontal stabilizer was removed for a spar inspection in accordance with AD DCA/CRESCO/4

Rear frame 08-11221-1 15 10

04/1861 DEF MA 31/05/2004 PWT Napier It was reported that the LH longeron was found fractured at the rear attach 1/4 bolt hole of the strut. In addition, the LH bush was missing, and both

Strut 08-10271-2 NSN 15 11


struts were found filed to assist the bolt head nesting. Both bolts were also found bent under the head.

05/376 DEF MA 19/01/2005 TML Taumarunui The pilot heard a loud bang during the pull-out after a lime sowing run.

Longeron and Frame

15 12

05/367 DEF MI 2/02/2005 TMM Hamilton It was reported that during inspection the longeron was found to be cracked at the rear bolt attachment of the welded strut.

Longeron 15 13

05/1484 DEF MI 5/02/2005 NZO Queenstown It was reported that the parachute door came off the tracks. The door was restrained only by drive strap jamming against the rear support.

Parachute Door

15 14

05/631 DEF MI 11/02/2005 LTL Wanganui It was reported that the cockpits left hand top longeron was found to be cracked from the engine mount strut small hole during strut inspection per PAC/CR/040 iss 3.

Cocpit Left Hand Longeron

15 15



UTCReg Location


07/1334 DEF MI 12/04/2007 TMM Hamilton Aeromotive LTD reported that during the 100 hour inspection the left hand longeron was found to be cracked through the rear attachement 1/4" bolt hole for the welded strut P/N 08-10271-4. The crack length was right around the longeron except the inner edg e.

Longeron 08-10271-4 15 16

93/5540 DEF MA 19/11/1993 TMN Bolt NAS 1306-78

245116 17

Annex F: Cresco Occurrences Page 162 Annex F: Cresco Occurrences Page 162


Reg Location Description Part Defective P/ N Part S/N TAIC Ref Class

05/1291 DEF MI 13/04/2005 JPP Switzerland The grease nipple was not installed on the nose landing gear pivot bolt P/N 08-457-11-1. Excessive wear was found on the associated bushings.

Grease nipple 2

07/1665 DEF MI 2/05/2007 JPU Hamilton JPU-During 1000 hour routine inspection, found the MLG (RH) lower torque link one leg broken off at the centre pivot point.

Torque link 2

06/1971 DEF MI 4/05/2006 FNZ Napier The Inertial Partical Seperator was found inoperative. Inertial Partical Seperator

11-50089-1 5

04/2143 ACC MA 4/07/2004 JPP Switzerland 14 skydivers were completing a jump in three groups, the first group departed successfully. During the second groups departure one skydiver struck the aircraft tailplane. �� He was uninjured but the aircraft received damage to the tailplane area. �

Tailplane/ Parts of Fuselage

106 7

05/2097 DEF MI 29/06/2005 JPP Switzerland Pilatus reported that the tail cone section of the aircraft contacted the ground.

Tail Cone 7

06/1129 INC MI 26/03/2006 FNZ Taupo A pilot landing an aircraft on grass runway 11 at Taupo made the appropriate calls whilst on approach. During this time trhe pilot of a second aircraft called and taxiied his aircraft onto grass runway 11/19 to back track and taxi for runway 35.

7

06/1747 INC MI 1/05/2006 TTL Taupo The pilot taxied his aircraft outside of the coned grass taxiway area close to runway 17/35. The pilot was advised, after a similar event the previous day, to use the correct area .

7

Annex G: 750XL Occurrences 163



06/1986 INC MI 20/05/2006 TTL Taupo Taupo Unicom reported that ZK-TTL took off on runway 17 without making any radio calls.

7

07/1846 INC MI 8/05/2007 TTL Taupo Airways reported that TTL was observed climbing after clearance was not given.

7

05/4370 INC MI 20/12/2005 JPU Taumarunui The aircraft failed to climb out of ground effect while taking off and the lower dorsal fin struck a fence. There was no structural damage to the aircraft.

9

05/3124 DEF MI 20/09/2005 JGI Goteborg City After turning on the electrical master switch during unscheduled maintenance work a sparking sound occurred. A maintenance technicians noted some flashing light from the centre consol in the cockpit. The power was immediately switched off.

Wiring Loom 10

01/3774 DEF MA 12/11/2001 XLA Hamilton The pilot of the Pacific Aerospace 750XL declared a full emergency because the right aileron jammed. Fortunately the aircraft managed to land safely.

Aileron controls 11

02/1568 INC MA 17/05/2002 XLA Hamilton While ZK-XLA was carrying out a test flight from NZHN, the pilot reported as being unable to trim the aircraft which became unstable. A PAN call was made. The aircraft subsequently carried out a safe landing at NZHN.

11

04/2152 DEF MI 23/06/2004 TTL Hamilton It was reported that during a routine 150 hour inspection, both right hand aileron push rod fittings were found loose in the rod. It was noted that the 1/8 inch TLP-D rivets were loose as if they had not pulled up the correctly, and the fittings were not a tight fit in the rod.

Push Rod Assembly

11-45121-2 11

04/2329 DEF MI 13/07/2004 FNZ Napier It was reported that the flaps would not extend or retract.

Flap Actuator NPC-01280 11




05/3655 DEF MA 1/11/2005 XLA Hamilton The pilot reported that the aircraft was taxied normally and lined up on the grass runway 18 at Hamilton. The take off was commenced and as power was applied and the speed increased the aircraft began to drift to the left of the centre line. Full reverse was applied and the take off was aborted. The aircraft was taxied back to the line up position and another take off commenced. Left drift was again encountered and momentarily corrected with the use of right wheel brake. When airborne and right rudder was applied to correct for the left drift the aircraft yawed further to the left. It was then apparent that the aircraft's rudder was operating in the opposite sense. The aircraft completed on circuit and landed without the use of the rudder.

Rudder 11

06/3646 DEF MI 27/09/2006 JPU Hamilton During a routine inspection the right hand flap remained stationary.

Flap torque tube

11-45631-1 11

07/593 DEF MI 18/01/2007 FNZ Napier Flight Care reported that the rear flexi - cable was too long causing it to rub on the elevator trim jack bellcrank. The outer sheath was broken at the point it crosses the bellcrank however had spiral-wrap over it hiding the defect. The inner cable was u ndamaged still allowing normal operation of elevator trim.

Elevator Trim Flexi - Cable

1434-00-41.00

11

07/435 DEF MI 2/02/2007 JPU Taumaranui The pilot reported that the flap circuit breaker was tripping.

Flap actuator 11-45505-1 11

07/823 DEF MI 14/02/2007 JOA Hamilton Pilot reported a failure of the autopilot system during a routine test flight causing the auto-pilot to disconnect without warning.

11




07/2252 DEF MI 29/05/2007 JPP Christchurch During scheduled maintenance it was found there was chafing between the flap and the aileron.

Aileron 11

07/2295 DEF MI 6/06/2007 JPU Hamilton During a routine 100 hour inspection the elevator trim system was checked and found to be making a grinding noise.

Planatary gearbox

J51-2 7674P 11

03/3794 ACC CR 26/12/2003 UAC 341 SSW KSFO The pilot of the ferry flight advised that he had a fuel problem and would not be able to complete the leg from Hawaii to mainland USA. A US Coast Guard C-130 was dispatched and rendezvoused with the aircraft, which ditched under the observation of the U SCG crew. The aircraft tipped onto its back on touchdown and the pilot did not surface. Pararescue swimmers dropped later from an Air National Guard MC-130 found the pilot dead.

12

04/678 DEF MA 22/02/2004 FNZ Napier It was reported that during the 300hr inspection, the airframe fuel filter element was found to be the incorrect part number.

Fuel Filter Element

1743045-01 12

04/4297 DEF MI 18/08/2005 FNZ Napier Fuel was seen dripping out of the fuselage when the aircraft was parked on the ground.

Hose Cross Feed

11-57115-1 12

05/2398 DEF MI 13/07/2005 JPU Hamilton A hole in a new part was found to have been miss-drilled by the part manufacturer.

Elevator hinge bracket

08-31169-3 13

05/1206 DEF MI 13/04/2005 JPP Switzerland A PAC 750 XL currently operating in Europe was found to have corrosion on several steel parts. This was found after the aircraft's first annual inspection.

Outer panel attach fittings

14

06/4970 DEF MA 2/02/2007 JPU Hamilton During investigation of a flap defect the wing rear spar was found to have to sheared fasterners and cracking.

Wing rear spar 11-20031-1/11-20032-

14




02/1786 DEF MA 10/06/2002 XLA Hamilton Several faults were found in the rear fuselage and horizontal tail surface after the aircraft had completed the spinning phase of its test flights.

Frame STA 369 & Horiz bulkhead

15

05/2096 DEF MI 29/06/2005 JPP Switzerland During an inspection it was found the cockpit door had loose hinges and a delamination of the outer skin from the inner skin.

Door Hinges and skins

15

07/2557 DEF MI 5/07/2007 JGI Gothenborg Sweden

A fuel pipe for the fuel system located in the cabin left side wall area has been damaged by chafing. No leakage had �occurred at the time of detection but wall thickness for the pipe has been locally quite decreased. �

Fuel Pi[pe 15



Reg Location Description Class Total

04/757 DEF MI 23/02/2004 JPC Wairamarama The pilot heard a loud bang from the undercarriage on take-off roll. The bungy assembly in suspension had failed by the support lug breaking. The wire cable back up cords also broke.

2 1

06/2193 INC MI 30/05/2006 JPC Opotoki The pilot reported that the left-hand main wheel rim cracked after going over going over a rabbit hole with full AUW.

2 2

97/1997 DEF MI 27/06/1997 MAW Blenheim Impulse coupling defects are worn and loose pawl pivot pins. Drive gear support bearings located in rear of crankcase have also been found defective. In the magneto we have had distributor low speed gear bearing bush worn out at 300hrs since new. Also the nylon drive gear located on rotor shaft worn on drive tongue allowing 15° to 20° of free movement. We have also had an impulse coupling retaining nut to shaft thread stripped. Nut only retained by split pin.

6 1

97/1998 DEF MI 27/06/1997 DMC Blenheim Impulse coupling defects are worn and loose pawl pivot pins. Drive gear support bearings located in rear of crankcase have also been found defective. In the magneto we have had distributor low speed gear bearing bush worn out at 300hrs since new. Also the nylon drive gear located on rotor shaft worn on drive tongue allowing 15° to 20° of free movement. We have also had an impulse coupling retaining nut to shaft thread stripped. Nut only retained by split pin.

6 2

97/1999 DEF MI 27/06/1997 CMC Blenheim Impulse coupling defects are worn and loose pawl pivot pins. Drive gear support bearings located in rear of crankcase have also been found defective. In the magneto we have had distributor low speed gear bearing bush worn out at 300hrs since new. Also the nylon drive gear located on rotor shaft worn on drive tongue allowing 15° to 20° of free movement. We have also had an impulse coupling retaining nut to shaft thread stripped. Nut only retained by split pin.

6 3

Annex H: GA200 Occurrences 168



98/3074 DEF MI 27/10/1998 CMC TIMARU The engine was in the workshop for a bulk strip due to a history of vibration causing constant Magneto defects.

6 4

99/2333 DEF MI 8/08/1999 CMC TAKAKA The rough running engine, cut out as power was reduced on approach.

6 5

01/2118 DEF MA 19/06/2001 MAW Woodbourne The aircraft made a perfectly successful forced landing 2nm south Woodbourne.

6 6

01/2975 DEF MI 10/08/2001 PGH Rangiora Not reported by operator. Defect report sent by maintainer.

6 7

02/1576 DEF MI 17/04/2002 MAW Omaka Investigation of dead cut L/H magneto revealed the contact assembly "spade" terminal to which the primary lead, from where the coil pushes on, was found to be broken.

6 8

03/408 DEF MI 14/01/2003 RMW Feilding Broken valve springs found during routine servicing (oil & filter change).

6 9

03/486 DEF MI 17/01/2003 RMW Feilding The operator reported that the right exhaust needed inspection. It was found that there was a piece missing from the pipe. ��

6 10

03/2414 DEF MI 18/07/2003 PGH Tokoroa Engineer reported the aircraft's engine was rough running during ground Mag Checks.

6 11

03/3339 DEF MI 4/11/2003 FJN Parnassas PIC reported the aircraft had very high fuel flow during topdressing operations. The engine cut out with idling power. Applying the axillary fuel pump restored normal fuel pressure.

6 12

04/1230 DEF MI 19/03/2004 NTO Unknown It was reported that the engine was running out of fuel without the collector tank low fuel light illuminating. The wiring terminals for indication system were found corroded in the collector tank.

6 13

04/1174 DEF MI 31/03/2004 PGH Unknown The engine magneto drive bearings had failed and the left and right hand magnetos were found destroyed inside.

6 14

04/3122 DEF MA 14/09/2004 DMC Lawrence It was reported that the aircraft experienced power loss directly after take off with only 2100 RPM. Smoke was seen coming from the exhaust and in the cockpit. The load was jettisoned and the aircraft returned to the strip.

6 15




06/1823 DEF MI 6/05/2006 NTO Feilding The engine number 5 cylinder was removed due to an oil leak from the base of the cylinder.

6 16

07/1124 INC MA 23/03/2007 EMD Pahiatua The pilot reported that the aircraft was returning to base when the engine lost all power. A forced landing was then carried out in a paddock. During the landing roll the aircraft went through a fence before coming to rest.

6 17

07/1700 DEF MI 21/05/2007 NTO Feilding The aircraft engine experienced an excessive magneto mag drop.

6 18

99/1200 ACC MA 2/05/1999 FMC Akaroa During transit between operating sites, via the south coast of Banks Peninsula, the pilot encountered an approaching front. He turned back to his departure point only to find that the weather behind had deteriorated. He landed on a farm property at the head of Peraki Bay, but the aeroplane sustained damage to the undercarriage, one wing, the forward fuselage and propeller on landing. The pilot was uninjured.

7 1

99/1526 ACC MA 27/05/1999 FMC Ohau En route to Palmerston North, the pilot encountered worsening weather conditions south of Levin. Rather than turn back, he elected to land the aeroplane in a farm paddock. Poor braking action due to long wet grass resulted in the aeroplane overrunning t he available landing space and colliding with the boundary fence. The pilot was uninjured.

7 2

99/2833 ACC MI 23/09/1999 CMC Awatere Valley The aircraft landed on a sloping topdressing airstrip in calm conditions and failed to stop due to excessive dew on the grass. The right hand wing tip contacted the bank causing minor damage to the wing and and propeller tips.

7 3

98/1840 DEF MA 28/06/1998 PRT Westport THE ENGINE LOST POWER ON TAKEOFF. THE LOAD OF WATER WAS DUMPED AND THE AIRCRAFT MADE A SAFE LANDING.

9 1




00/655 ACC MA 22/03/2000 PGH Lake Brunner The pilot was conducting supervised spraying operations from a sealed strip with a grass extension at either end. The supervising pilot had been taking 600-litre loads throughout the morning, and it was the intention of the pilot under supervision to sta rt with 500 litres.�However, 600 litres was loaded inadvertently on the first flight of the afternoon, and the pilot decided to continue with that load. The take-off run started from the grass short of the sealed strip, but when the aircraft ran on to the seal, a slight tailwheel shimmy developed. The pilot applied light braking to assist in raising the tail, but then encountered directional control problems on the cambered strip, exacerbated by a quartering crosswind.�The aircraft failed to become properly airborne, over-ran the departure end of the strip and collided with a fence, sustaining substantial damage. The pilot was not injure

9 2

01/41 ACC CR 10/01/2001 PGH Amberley Significant event: ZK-PGH had completed a downhill spray run. As the aircraft climbed up the other side of the gully it crashed into the ground.

9 3

01/308 ACC CR 29/01/2001 FMC Guards Bay ZK-FMC had its propeller strike the ground just before lift off from a fairly steep topdressing airstrip. The pilot immediately jettisoned the load and endeavoured to complete a forced landing on the beach below the strip but failed to reach the area a nd subsequently ditched into the sea

9 4

02/2082 ACC MA 28/06/2002 RMW Waituna West The aircraft failed to become airborne off the farm strip after the pilot jettisoned the load, and it clipped a fence post. The hopper door was flung back, damaging the cockpit floor, and putting two holes in the fuselage fabric.

9 5

04/3022 INC MI 18/09/2004 JPC Glenmarry Airstrip

It was reported that the aircraft's wing tip touched the ground on take off after experiencing some sink. Damage was found on the outer wing so the aircraft was flown back to base for repairs.

9 6


05/3596 ACC MI 6/11/2005 EMD Pongoroa It was reported that the aircraft hit a hill whilst top dressing.

9 7

04/3251 DEF MA 7/10/2004 MAW Blenheim It was reported that during a 100 hour inspection the rudder cable was found to be almost severed.

11 1

06/2675 DEF MI 29/06/2006 PGH Rotorua The aircraft was sowing urea when at the end of a sowing run the A frame on the hopper door opening broke on both sides of the hopper door. The front of the spreader dropped down and caused a vibration. Power was reduced and the aircraft landed back on th e strip.

15 1


OCC_No Code SevDate Time UTC

Reg Location Description Part Defective Class Total

07/384 DEF MI 16/01/2007 JHG Feilding The aircraft tail spring broke during the takeoff run.

Unknown 2 0

07/1523 ACC MA 8/05/2007 MAA Five Rivers The aircraft had an accident on takeoff during an agricultural operation, which caused substantial damage.

Fin Structural Failure 2 1

08/828 DEF MI 11/02/2008 JHG Woodville

Refer to Engineering. Pilot reported Vibs onlandingthroughLH brake pedal. Vis inspection found dust cap axle nut and outer bearing caged missing.

Rudder 2

08/2284 DEF MI 8/05/2008 JHG FeildingRoutine inspection found RH rear u/c clamp attachment weld cracked.

Landing Gear Structural Failure

2 2

07/2325 DEF MA 29/06/2007 PTK Napier The aircraft was top dressing 3nm West of Napier airfield when the pilot reported an engine failure. The aircraft then joined for grass runway 07 and landed without incident or damage.

Wing Attachmnets 5 3

01/2927 INC MI 6/07/2001 JHG Masterton Aircraft had taken off from greasy agricultural strip with pilot not realising the park brakes were not fully released. Aircraft subsequently nosed-over when landing on sealed runway at Masterton destroying the propellor and damaging internal engine compo nents.

Engine Mount 7 4

06/3660 INC MI 28/09/2006 SAT Lavericks Bay While spreading super-phosphate around a farm the pilot accidentally flew the aircrafts' undercarriage into the "Orion Network" High Voltage 11kVt overhead powerline spanning across the valley. The line broke due to 'wire-cutters' on undercarriage severi ng the cable.

Turbine Engine 7 5

06/985 DEF MI 2/02/2006 PTK Napier The propeller gaskets were found to be defective during an inspection.

Piston Engine 8 6

Annex I: Air Tractor Occurrences 173

OCC_No Code SevDate Time UTC

Reg Location Description Part Defective Class Total

07/935 ACC MA 5/03/2007 PTK Waipoapoa Station

The aircraft encountered sink after becoming airborne and the pilot initiated a load jettison. However the aircraft struck a fence and caused substantial damage to the rear wing spar and ailerons. The pilot made a successful out landing in a paddo ck approximately 3 miles away.

Operational Error 9 7

Annex I: Air Tractor Occurrences 174

OCC No Code Sev Date Time UTC Reg Location Description Part Defective

Code Total

70/26 ACC MA 30/10/1989 CSC OMAHUTA FOREST 0 1

70/28 ACC MA 13/09/1991 ESL NOT KNOWN 0 2

70/67 ACC MA 13/10/1991 DPA TAUPO 0 3

70/84 ACC MA 6/07/1992 DSA UNKNOWN 0 4

70/105 ACC MA 21/07/1992 DSA UNKNOWN 0 5

71/12 ACC MA 16/11/1992 DPW MOSGIEL 0 6

71/26 ACC MA 5/02/1971 CSF NR MASTERTONCollapse of the tailwheel mounting tube caused loss of directional control on takeoff. the pilot vacated the aircraft to investigate and the unattended aircraft rolled down a bank. one undercarriage leg collapsed and the aircraft dropped onto one wing.

2 1

71/38 ACC MA 21/07/1971 CSE CHEVIOT At the start of the takeoff roll the tailwheel jammed in the fully deflected position. directional control could not be maintained on the slippery surface and the aircraft groundlooped into a fence and slid backwards into a gully.

2 2

71/42 ACC MA 29/01/1973 CSK OTAKI Failure of the righthand main leg saddle bolts during the landing roll caused the pilot to lose directional control, as the result of which the aircraft groundlooped and the leg folded underneath the fuselage.

2 3

71/67 ACC MA 23/07/1973 CQY TUAPEKA WEST The right undercarriage main attachment bolt failed during takeoff but the pilot was able to maintain control and made a landing back at base with minimal damage.

2 4

71/98 ACC MA 9/09/1973 CQZ THE KEY The pilot reported that when landing from a topdressing sortie the tail sank lower than usual. inspection revealed that the tail spring had broken in the vicinity of station 224.

2 5

Annex J: Cessna Agwagon Occurrences 175


Code Total

72/38 ACC MA 19/11/1973 CSD AWATOITOI STN Aircraft about to lift off from topdressing strip with 15cwt load of superphosphate when port undercarriage leg separated. metallurgical examination of the fracture surfaces revealed a brittle fracture which had been initiated by a small fatigue crack in a fretted area on the

2 6

72/79 ACC MA 31/01/1974 CSD LONG BUSH The pilot was completing a ferry flight with his loader driver to begin operations from the strip. the aircraft bounced on landing and touched down again on the rough verge. the left undercarriage leg collapsed when the aircraft was brought to a stop and the aircraft then ran backwards over the side of the strip.

2 7

72/118 ACC MA 5/03/1974 CSA AWAKINO At touchdown the lefthand main wheel collapsed and in the ensuing ground loop the starboard wing and nose of the aircraft were extensively damaged.

2 8

72/122 ACC MA 19/04/1975 CQM AHUROA Shortly after starting a takeoff run down the steep slope of the strip the pilot heard a bang and felt vibration throughout the aircraft. he abandoned the takeoff. during a ground loop made to stop the aircraft, one undercarriage leg collapsed. the tail wheel pivot bolt was found to have failed from fatigue, thereby allowing the tail wheel to become detached.

2 9

73/23 ACC MA 2/03/1976 CQV AWAKINO To avoid going over the side of the strip when the aircraft began to veer to the left after landing the pilot initiated a groundloop in the same direction. separation of the lefthand leg during the loop was found to have been caused by prior overstressing of the saddle forward attachment bolt.

2 10

73/29 ACC MA 19/03/1976 CSK COLYTON A groundloop occurred while the aircraft was being manoeuvred for takeoff as the result of which the righthand main undercarriage collapsed.

2 11

73/48 ACC MA 30/11/1978 DMD AWARUA The aircraft lost a wheel during the takeoff from a strip and was damaged in the subsequent landing.

2 12



Code Total

73/79 ACC MA 23/03/1980 DOE KAIHU On landing a fatigue crack caused the aircraft's tailwheel spring to fracture during the landing roll.

2 13

73/88 ACC MA 8/10/1980 DMD OMAMARI The aircraft ran off the side of the strip when the right brake failed during a down wind landing.

2 14

73/100 ACC MA 3/03/1982 DOE NR TAUMARUNUI The aircraft's right undercarriage leg separated on takeoff and the pilot made a successful precautionary landing at his base airfield. the fatigue fracture of the leg had initiated at corrosion pits on the surface of the metal.

2 15

73/140 ACC MA 11/05/1982 DME EAST STRATFORD On landing the aircraft ran through a concealed drain on the strip. the right undercarriage leg separated and the aircraft came to rest nose down.

2 16

74/15 ACC MA 8/03/1984 DOE PIRIAKA On landing the aircraft bounced then sank to the left when the left undercarriage spring leg fractured at the mudguard attachment bracket. the failure was due to a fatigue crack originating from a corrosion pit.

2 17

74/30 ACC MA 24/10/1985 DOZ WAIRAKEI The right mainwheel separated from the aircraft after takeoff due to the failure of unsuitable retaining nuts fitted to the axle retention bolts. the aircraft tipped onto its nose and left wing tip at the end of the subsequent landing run.

2 18

74/71 ACC MA 11/04/1995 LDZ SOUTH OTAGO FIRST LANDING ON STRIP FOR START OF TOP DRESSING OPS. ARRIVED A LITTLE FAST AND HAD TO SWERVE TO AVIOD HITTING LOADER GRASS VERY WET ONE MLG LEG COLLAPSED

2 19

74/82 ACC MA 28/11/1996 JCR WANGANUI Six brake discs were found to be cracked during a routine inspection. Corrosion was found around the weld area attaching the cup shaped mild steel pressing to the disc. This had significantly weakened the weld. This was considered to be a manufacturing f ault and due to lack of protective coating.

Brake 2 20



Code Total

74/110 ACC MA 16/11/1997 LDZ Dunedin During the landing of a light aircraft the aircraft spun 270 degrees to the left and ended east of the runway. Damage to the right side of the undercarriage occurred.

2 21

74/116 ACC MA 15/07/1970 CQQ TARAPATIKI After liftoff the windscreen became covered with oil, engine began to overspeed and propeller thrust become '0'. in forced landing, initial impact taken by right wing against steep slope. aircraft cartwheeled and came to rest inverted in a stream where it caught fire. pilot retained consciousness and was able to extricate himself and move away. (investigation details in summary

6 1

74/122 ACC MA 6/12/1972 COT ASHLEY GORGE A complete and sudden power loss during a gorse-spraying operation necessitated forced landing on rough terrain. cause of the power loss was fatigue failure of no. 4 connecting rod.

6 2

75/54 ACC MA 30/09/1974 COQ NR RAETIHI The aircraft was extensively damaged during a forced landing on rough terrain following a total power loss during a flight to the sowing area. a strip examination revealed the top land of no. 5 piston worn away and pieces of broken ring in the combustion chamber.

6 3

75/60 ACC MA 14/04/1989 DMA NR TE PUKE Following an engine and power loss at low level the aircraft collided with a wire and spun to ground level.

6 4

75/133 ACC MA 13/03/1993 EJL Cheviot Engine failure, forced landing 6 5

75/137 ACC MA 29/03/1994 DSA Masterton Engine failure, forced landing CONROD,CRANKSHAFT

6 6

76/39 ACC MA 14/11/1995 DPA TAIHAPE On flight in company with DEP from Fielding to Hastings. Had engine failure and put down in scrub without injury. The aircraft destroyed by fire

6 7

76/40 ACC MA 14/09/2001 JCR Feilding While AD DCA/Con/140a was being executed it was found that the IO-520 exhaust valves were excessively corroded.

Exhaust Valves

6 8



Code Total

76/42 ACC MA 31/10/2001 EJL Culverden At the conclusion of the topdressing job the pilot landed and shutdown the aircraft so he could load some personal gear on board. It was at this time he heard a fluid 'running' sound and saw that oil was pouring from the engine area. It was found that a h ose clamp had come loose and allowed the remote oil cooler pipes to wear against the sump.

Oil pipes and clamp

6 9

76/49 ACC MA 14/09/2003 CSM South Island The Agwagon had just got airborne when a loss of power was experienced and the pilot made a forced landing.

Muffler 6 10

76/51 ACC MA 6/10/2006 LDZ Balclutha Pilot noticed a loss in power on take-off, managed to negotiate a circuit and land without incident

Cylinder assembly

6 11

76/63 ACC MA 19/10/1970 CQP MARTON While the aircraft was crop spraying, the right wing struck a dead branch of a gum tree on the edge of the field. the pilot maintained control and returned to the airstrip. the pilot had misjudged clearance between the wing and the tree.

7 1

76/75 ACC MA 8/12/1970 CQT BUNNYTHORPE Crop spraying was being carried out at last light. approach made over 60 ft trees. during round-out at spraying height, aircraft stalled and squashed heavily into crop. travelled 50 yds, then became airborne, but rapidly reduced airspeed influenced pilot to land in adjacent paddock. while approaching, aircraft stalled, landed heavily. fire in battery and destroyed aircraft.

7 2

76/84 ACC MA 1/11/1971 CQJ KINLEITH During a cross-wind landing on an aerial work airstrip the left wheel ran into a soft patch and loss of control occurred. the aircraft groundlooped to the left and came to rest on a reciprocal heading beyond the side of the strip.

7 3



Code Total

77/17 ACC MA 18/03/1972 CQX OHINGAITI During a spray run one wing collided with a piece of rusty water pipe protruding from the crop. in flight the obstruction was almost visible against a background of ripe barley. the farmer knew of the obstruction but had not considered it significant enough to warn the pilot.

7 4

77/49 ACC MA 2/02/1973 CSM PATEA During a cross country ferry flight deteriorating weather necessitated a precautionary landing being made on a golf course. shortly after touchdown a previously unseen hummock caused the aircraft to be thrown 40-50 ft into the air and in the subsequent ground impact the port undercarriage leg was torn off.

7 5

77/79 ACC MA 14/10/1974 CQK NR TE ANAU At the completion of a topdressing run the pilot failed to maintain adequate terrain clearance and the aircraft collided with high tension power lines.

7 6

77/103 ACC MA 8/11/1974 CQY WAITAHUNA The pilot landed his aircraft in a paddock too fast and too close to a tanker. he braked but wet grass made this ineffective and an attempted groundloop to avoid the tanker resulted in the aircraft's elevator and tailplane striking it.

7 7

77/108 ACC MA 8/05/1975 DPC NR WAINUI The pilot partially applied brakes on his first touchdown on the strip. a fresh tail wind was blowing. the tail rose and after skidding for 60 yards the aircraft overturned.

7 8

77/123 ACC MA 8/12/1975 CQY WAITAHUNA The pilot touched down on an uphill-sloping strip. as the upper part of the strip came into view during the landing roll the pilot realised that he was off-line and heading towards a gully. he endeavoured to groundloop but was unable to prevent the aircraft from sliding down a bank.

7 9

78/3 ACC MA 26/12/1975 DOY CHEVIOT After completing a spray run over steep terrain the pilot pulled sharply into a climb near a lone pine tree. he encountered light turbulence and the left wing struck the tree.

7 10



Code Total

78/46 ACC MA 4/03/1976 CSB RANGITIKEI RVR The pilot dived left to avoid a large flock of seagulls which rose directly in front of the aircraft, but then collided with unseen telephone lines strung from a high bluff.

7 11

78/145 ACC MA 12/05/1976 CQV NR WAITOMO While landing on an exposed airstrip in unfavourable weather conditions, the pilot experienced difficulty in maintaining directional control. a wheel entered a washout on one side of the strip and the aircraft fell off the strip.

7 12

78/158 ACC MA 13/06/1976 DOE MATAKOHE After landing the brakes were ineffective on wet grass and the pilot yawed the aircraft sideways to increase effectiveness but one wheel ran over the side of the strip and the aircraft collided with a tree.

7 13

79/17 ACC MA 22/07/1976 CQJ MATAHIWI When wind conditions became unsuitable for further topdressing the pilot decided to terminate operations from the strip and return to base. as the takeoff roll was commenced a cross-wind gust lifted the port wing bringing the starboard wingtip, stub wingtip and propeller into contact with the ground. thereafter the aircraft swung through 240 deg and struck a fence

7 14

79/39 ACC MA 4/02/1977 CSE AVON VALLEY The strip being used sloped out of the pilot's view after the first 100 metres. he mistook the direction of takeoff and the aircraft sank into a hollow containing large stones. the left undercarriage collapsed and the aircraft slid to a stop.

7 15

79/45 ACC MA 17/03/1977 DPU RANGIWAEA The aircraft undershot a selected touchdown point by approx 15 feet. contact with rough ground in the undershoot area resulted in the left under-carriage leg being torn from its mounting.

7 16

79/125 ACC MA 12/10/1977 DPX WAITANGIRUA After touchdown following a normal approach for a downwind/uphill landing the pilot applied brakes very firmly and the aircraft overturned.

7 17



Code Total

80/45 ACC MA 6/01/1978 CSM NR TOKOROA On takeoff the aircraft ran into a cloud of pumice dust which it had created turning around on the strip. after abandoning the takeoff a groundloop was initiated to prevent the aircraft going over a steep drop off the end of the strip.

7 18

80/110 ACC MA 13/11/1978 DJZ TE KUITI AD Aerodrome closed due to flooding and an appropriate notam issued. when pilot landed on grass, he encountered a large pool of water which was hidden by long grass and the resultant drag flipped the aircraft on its back. the pilot was not aware of the closure which occurred after he departed earlier in the day.

7 19

81/80 ACC MA 26/02/1979 CSC HOTEOE While the pilot was landing the aircraft with the sun in his eyes, he felt a jolt and heard a bang and immediately initiated a go around. the aircraft had hit a sheep which had wandered onto the strip. one undercarriage had been dislodged and when the aircraft landed back at base it dropped onto its wingtip.

7 20

82/28 ACC MA 1/03/1979 CSM WAIOURU AD After touchdown in gusty conditions with moderate turbulence the aircraft became airborne again drifting sideways. an attempt to control the aircraft was unsuccessful and it was substantially damaged in the ensuing groundloop.

7 21

82/52 ACC MA 11/10/1981 CQD PUNGAREHU The pilot misjudged the approach for a crosswind landing on an uphill landing strip made greasy by recent rain. he was unable to prevent the aircraft sliding into the loading area and colliding with the parked loading vehicle. no overshoot was practicable and the pilot's attempt to groundloop the aircraft was unsuccessful.

7 22

82/122 ACC MA 29/05/1984 DRZ HINAKURA The pilot was unable to maintain directional control of the aircraft when taking off in a strong gusty cross-wind. he was committed to takeoff and the aircraft collided with a fence.

7 23



Code Total

83/55 ACC MA 26/11/1984 DPA CHELTENHAM A wheat crop on the side of the airstrip had grown since the strip was last used. on landing the spray boom struck the wheat and the aircraft groundlooped.

7 24

84/31 ACC MA 9/04/1985 DMD NR EASTBOURNE The pilot vacated the cockpit quickly when a bee or a wasp started to bother him. he inadvertently knocked the throttle open and then fell off the wing as the aircraft rolled forward and collided with the fertiliser bin.

7 25

84/52 ACC MA 18/05/1985 DOE TE KUITI AD On departure the pilot taxied the aircraft into a patch of ground fog. the windscreen frosted over and the aircraft's right mainwheel dropped into a drain beside the runway.

7 26

84/114 ACC MA 2/01/1987 DHX STANWAY On landing the aircraft's sprayboom snagged in a tall crop alongside a narrow airstrip and caused the aircraft to groundloop.

7 27

85/35 ACC MA 8/05/1992 DPA Taupo Ad Taxied into fuel pump 7 28

85/36 ACC MA 29/04/1994 DPX KIMBOLTON ON T/O ROLL A/C VEERED TO RIGHT GETTING OUT OF CONTROL BECAUSE OF THE STEEP GRADIANT OF THE STRIP. DAMAGE TO A/C

7 29

85/47 ACC MA 7/09/2001 CSM Kahatara After startup, aircraft was being taxied down the side of the company's airstrip when the propellor struck a haybale, damaging the propellor.

7 30

85/94 ACC MA 5/11/1979 CXO NR STRATFORD The pilot opened the throttle to maximum power for takeoff and shortly after, the propeller separated from the engine. the threaded shank of one propeller blade had failed just below the top of the ferrule which holds the blade. the fracture could not have been detected visually without dismantling the propeller.

8 1



Code Total

87/5 ACC MA 23/02/1970 CQO RANGITOTO The aircraft failed to clear a ridge beyond the departure end of the strip. the pilot reported that the jettison would no operate. aircraft stalled, struck the face of a ridge, bounced and slewed into a fence. no defect was found when the hopper operating mechanism was subsequently examined by a civil aviation division aircraft surveyor.

9 1

89/42 ACC MA 25/02/1970 COP TUTAENUI Just after taking off on 8th topdressing sortie since last refuelled, the aircraft disappeared from sight beyond end of strip, crashed and burned. pilot fatally injured. probable cause: sudden loss of lift arising from unexpected wind change encountered at a critical airspeed immediately after takeoff and which resulted in aircraft striking the ground.

9 2

89/66 ACC MA 3/03/1971 CSL TE KARAKA The aircraft sank after takeoff and collided lightly with a tree. the pilot returned to land at the strip but the aircraft stalled short of and below the threshold and the undercarriage was torn off at impact.

9 3

89/86 ACC MA 16/04/1971 CSC MANDEVILLE Just after liftoff the aircraft sank and made brief but heavy contact with the ground. control was maintained and the aircraft was flown to base for repair.

9 4

91/694 DEF MA 27/08/1972 CQL NR TAIHAPE While taking off from a steep but soft airstrip the pilot realised that he would not become airborne and operated the jettison, but too late for it to be effective. the aircraft sank off the end of the airstrip, the undercarriage struck an earth bank, and the aircraft overturned

9 5

91/904 DEF MA 28/11/1972 CSC PUKEMAORI On takeoff from a steep undulating strip the aircraft became prematurely airborne after striking a terrain hump. as flying speed had not been attained the aircraft sank heavily on to the tailwheel causing it to separate from the aircraft and extensively damage the rear fuselage

9 6



Code Total

92/1121 ACC MA 6/03/1973 DHX AWARUA During a downwind takeoff the pilot inadvertently raised the flaps instead of jettisoning the load and the aircraft failed to become airborne. the pilot had recently converted from another type in which he had flown 5000 hours and in which the hopper and flap levers were located in positions the reverse of those in the cessna a188.

9 7

92/1325 ACC MA 18/06/1973 CQV NR RAETIHI Due to hoar frost on the wings and a slight tailwind the aircraft sank after takeoff and collided with a boundary fence.

9 8

92/2320 DEF MA 30/05/1974 CQK LUMSDEN The aircraft sank back on to the strip following premature liftoff with an inadvertent overload and collided with three fences before coming to rest.

9 9

92/2215 DEF MA 9/07/1974 CQZ ACTON RIVER VLY Due to power loss aircraft sank off end of strip and impacted with lower ground. full flap had been applied to lift weight off wheels early in takeoff. just refuelled, it seems likely that being suddenly deprived of ground effect as passed off end of strip in low-speed high-drag configuration, aircraft sank in semi-stalled condition and pilot interpreted it as power los.

9 10

92/2625 ACC MA 11/03/1976 CQN NR NGAROMA After liftoff on the 66th takeoff of the day a momentary power loss was experienced. after jettisoning the load the aircraft passed through two fences before becoming airborne. a water droplet or foreign particle in the fuel injector was considered the most likely cause of the power interruption

9 11



Code Total

92/2655 ACC MA 25/03/1976 DOE TITOKI As the tail was slow to rise during a takeoff the pilot attempted to dump the load but found the hopper lever jammed. while he was attempting to free the lever the aircraft veered off the normal takeoff path and over a hump. as it became airborne it collided with a fence at the end of the strip.

9 12

92/4148 DEF MA 8/06/1977 CQS MANUTAHI The aircraft collided with level ground below the strip after takeoff causing the left undercarriage leg to fail. the pilot made an emergency landing at new plymouth airport.

9 13

93/1250A ACC MA 22/08/1977 CQS MIDHURST After a normal takeoff run the aircraft lost height off the end of the strip. the pilot was unable to avoid colliding with the terrain and the aircraft came to rest inverted.

9 14

93/3453 ACC MA 6/09/1977 DPV NR BALCLUTHA After aircraft airborne it began to sink. pilot attempted to jettison but this was ineffective. aircraft nosed down sufficiently for propeller to strike ground lightly and shatter pitch charge links which thus prevented the propeller from adopting any useful angle of attack. the pilot was unable to prevent aircraft colliding with a fence and eventually tracking into ditch.

9 15

93/3223 ACC MA 13/03/1978 CQI ARGYLE EAST During the takeoff run the pilot elected to jettison the load. he was unable to obtain the 'full dump' setting because the inertia reel of his shoulder harness locked. he closed the throttle but was unable to avoid a collision with the fence.

9 16



Code Total

93/6084 DEF MI 23/12/1982 DPP KNAPDALE At commencement of spraying operations it became apparent aircraft would not become airborne before reaching end of airstrip. pilot operated dump control and aircraft lifted off but struck some gates just beyond strip dislodging right wheel and spray pump assembly. during ensuing landing right undercarriage dug into ground and both u/c legs were torn out as aircraft groundlooped

9 17

94/84 ACC MA 6/06/1983 CSB NR AWAKINO The aircraft was climbing towards a ridge en route to the sowing area when the pilot initiated a turn away from the terrain. however, the aircraft struck the face of the ridge during the turn. the pilot was fatally injured and the passenger was seriously injured in the post-accident fire.

9 18

94/759 ACC MA 10/04/1985 EJL NR HOKONUI The aircraft became airborne but started to sink towards a fence just off the end of the airstrip. the pilot selected full jettison but the aircraft's right mainwheel struck a concrete fence post.

9 19

94/1243 ACC CR 10/08/1989 DSA MARTINBOROUGH After travelling about 100 m on its takeoff run the aircraft veered to the left despite the pilot's application of full right rudder and then right brake. the pilot jettisoned the 600 kg load of d.a.p. as the aircraft left the strip. the aircraft continued through a fence, across a road and into a second fence.

9 20

94/2639 INC MI 2/09/1992 FYJ nr Otane Failed to get airborne, hit ditch 9 21

94/4047 ACC CR 6/09/1992 EJK Feilding Failed to get airborne, hit fence 9 22

95/1003 ACC CR 29/04/1993 DHX Raetihi Failed to get airborne, hit fence 9 23

95/3303 ACC CR 18/07/1993 CQX Havelock North Hit trees on takeoff 9 24

96/3571 DEF MA 13/01/1994 DPA Kairanga Strip Failed to become airborne, overran paddock 9 25

97/3348 ACC MI 3/03/1994 CQY Seaview, Seddon Sink on takeoff, load jettisoned, but hit fence 9 26

98/526 ACC MA 24/10/1994 TJK Akatore Power loss after takeoff, landed heavily 9 27



Code Total

98/599 ACC CR 7/03/1998 EMD Pongaroa During the final run of a topdressing operation the aircraft had turned downwind and was caught in sinking air. Performance was inadequate to clear terrain and the aircraft impacted at the top of a ridge. Aircraft destroyed, pilot sustained a minor injury .

9 28

01/2305 ACC MA 13/03/1998 DPX Haupiri V The aircraft took off with a load of liquid fish fertiliser and turned towards the treatment area near the Haupiri River gorge. One spray run had been completed and the aircraft commenced a right procedure turn. About three quarters of the way through the 180 degree turn, the aircraft struck the top of trees and crashed to the ground, inverted. According to the pilot, the weather conditions were favourable with nil wind, slight overcast and fair visibility.

9 29

01/3108 INC MI 7/07/2001 CSD Akaroa The aircraft failed to become airborne off a farm strip and slid down a bank and was destroyed. The pilot was not hurt.

9 30

01/3273 DEF MI 1/09/2002 JCR Clinton The aircraft failed to accelerate as expected so the pilot tried to jettison the load but this did not help. As a result the aircraft over-ran the strip coming to rest on a slope below the runway. It then caught fire and was burnt out.�

9 31

01/4379 DEF MA 4/09/2004 DHX Gwavas Airsrtip It was reported that the aircraft was hit by a tail wind gust during take off. This resulted in the plane hitting the ground and going through a fence. The aircraft then went over a 50 metre bank before coming to a rest on a creek bed.

9 32

02/2572 ACC CR 6/12/1993 ESL MOSGIEL "G" SWITCH 10 1



Code Total

03/3953 DEF MA 7/04/1971 CQY SILVER PEAK During 31st takeoff a total power loss occurred necessitating forced landing in inhospitable terrain. in subsequent test, engine started normally and developed rated power. auxiliary fuel pump was reportedly not switched on when the power loss occurred and is probable that by-pass valve which showed evidence of sticking caused a restriction of fuel flow to engine-driven pump

12 1

04/2822 ACC CR 29/01/1979 CSA NR PONGAROA As the aircraft was returning from a topdressing sortie the engine lost power. the pilot was unable to rectify the fault and attempted to glide the aircraft to the strip. this proved impracticable and the aircraft was damaged after it touched down in a short sloping field. there was no fuel evident in the aircraft's tank after the accident.

12 2

04/3396 ACC CR 21/04/1992 DHX Apiti Fuel exhaustion 12 3

06/4047 DEF MI 23/10/2004 CSM Omihi The pilot suffered an incapacitating event at take off and was unable to maintain control of his aircraft.

16 1



UTC Reg Location DescriptionTAIC Reference Class Total

77/11 ACC MA 23/01/1977 CVD PUHOI The aircraft became overdue on a topdressing sortie. its wreckage was found later in thick bush just over half a mile from the airstrip from which it had been operating. the sole occupant received fatal injuries.

77-012 0 1

82/86 ACC MA 12/09/1982 TRO LOWRY PEAKS RGE

The aircraft was engaged in topdressing a steep hill country property when it failed to return from the third sortie. the burned out wreckage of the aircraft was subsequently located in a gully at the extremity of the area being sown. the pilot was fatally injured in the accident.

82-086 0 2

00/2540 NRO MA 5/08/2000 DUPLICATE REFER TO OCC No 00/2616 0 3

70/32 ACC MA 8/03/1970 CWM TAINGAIHEOn landing, the nosewheel assembly collapsed and the aircraft turned upside down. assembly collapse was attributed to fatigue failure of the nose leg hinge bolt.

2106 2 1

72/83 ACC MA 6/09/1972 CVB KAWAKA Before using a new airstrip for the first time the pilot flew over it, noting that the surface appeared firm, dry,and clear of obstructions. after a normal landing the nosewheel ran into a soft area and folded rearward. the aircraft then overturned.

72-075 2 2

74/59 ACC MA 6/05/1974 DMZ PUKENUIAircraft carrying 15 cwt hopper load was beginning 7th takeoff from an agricultural airstrip. about 30ft beyond takeoff initiation point, nose wheel seen to collapse and aircraft, arrested by ground friction, slowly pitched forward, nosing over into an inverted attitude in which overturn truss collapsed. pilot trapped by head beneath aircraft, and died before extricated.

74-055 2 3

75/126 ACC MA 1/12/1975 DMZ OMAKERE The transverse tubular member of the engine mount which supports the nose gear fractured at the weld clusters causing the nose gear to collapse.

75-123 2 4

84/86 ACC MA 24/08/1984 TRN NR TE PUKEThe left undercarriage support pylon failed on takeoff. on landing the aircraft settled onto the stub wing.

84-090 2 5

Annex K: Transavia PL-12 Airtruk Occurrences 190



77/33 ACC MA 18/02/1977 DVP DUDERS POINT

The new 'tiara'-powered airtruk suffered sudden power loss in-flight and made a heavy forced landing. it is considered likely that the engine stopped through a 'rich cut' when the auxiliary fuel pump was accidentally switched on in flight. there was no information available to the pilot that this pump could not be used in-flight.

77-031 6 1

79/104 ACC MA 2/09/1979 DMK RAHOTU The engine stopped soon after takeoff due to fuel exhaustion in the selected fuel tank. fuel flow could not be restored before the aircraft struck the ground. the fuel gauge in this tank over-read considerably. the gauge had recently been repaired but was not recalibrated on completion of the repair

79-102 6 2

98/2117 ACC MA 4/08/1998 TRS MastertonThe aircraft suffered an engine failure after take-off, about 200 m from the end of the strip. The pilot managed to carry out a successful forced landing in a paddock ahead, but with minor damage to the aircraft when it struck the downwind fence. The en gine had given a burst of power again after the initial failure.�An engineering investigation found that the flight was the pilot's last before he intended refuelling. Prior to take-off, the aeroplane had been sitting on sloping ground, allowing the fuel to cross-feed to the lower tank. The fuel outlet unported during take-off, causing the power loss. The pilot was committed to force-landing the aircraft and did not have time to select the electric boost pump on before touching down.

6 3

71/1 ACC MA 2/01/1971 CVA ARDMORE AD During circuit training involving a series of takeoffs and landings, the engine lost power during takeoff due to fuel starvation. realising that the safe endurance of the tank in use had been exceeded the pilot selected the other tank but was unable to effect a restart in time to avoid a forced landing.

71-001 7 1




73/127 ACC MA 24/10/1973 DMY PERIA During refuelling operations some fuel was spilt on the stub wing. at start-up a sheet of flame from the exhaust ignited the fuel. the fire extinguisher was not in its normal position on the loading vehicle and with no means of controlling the fire flames spread rapidly and consumed the aircraft.

73-126 7 2

75/52 ACC MA 14/04/1975 DMK OPARAU Sheep had been cleared from the strip but during the first takeoff a sheep crossing in front of the aircraft was struck. severe vibration followed and the pilot was unable to stop the aircraft on the sloping strip. the aircraft landed in a paddock below.

75-050 7 3

75/112 ACC MA 21/10/1975 DMK NR MANGONUI

While approaching a steep sloping airstrip, airspeed was allowed to decrease too much and a high sink rate developed. corrective action failed to arrest it and the aircraft landed very heavily.

75-108 7 4

75/128 ACC MA 4/12/1975 CJT TINUI The aircraft landed heavily after application of full power had failed to arrest sink rate incurred after a severe downdraught was encountered during final approach.

75-139 7 5

76/139 ACC MA 3/12/1976 DMK PAPONGA The very inexperienced topdressing pilot did not heed the advice of experienced pilots that weather conditions at the airstrip would be unsuitable for topdressing operations. while landing on the strip severe downdraughts and turbulence caused the aircraft to land very heavily

76-140 7 6

78/65 ACC MA 23/04/1978 DNA WAIMATENUI Wet grass and a tailwind resulted in the pilot being unable to stop the aircraft when landing after his first topdressing flight for the day. the aircraft ran into a ditch and tipped up onto its nose.

78-061 7 7

78/76 ACC MA 20/05/1978 DNA HOUTO Aircraft operating from a strip which had recently been resurfaced with topsoil by owner. area to be used compacted by a truck driving over it. 42 sorties operated normally off strip before a slight increase in tailwind persuaded pilot to land little closer to strip's threshold. after touchdown nosewheel entered an area of soft uncompacted soil and aircraft nosed over.

78-076 7 8




83/58 ACC MA 13/07/1983 CWX TANGITERORIA

While descending from a reversal turn the aircraft struck power conductors suspended in a long span across a valley. the conductors were broken by the impact and the top of one empennage separated from the aircraft. the pilot flew the aircraft back to the airstrip using the remaining empennage and landed without further incident.

83-058 7 9

84/20 ACC MA 14/02/1984 CJU TANGITERORIA

The pilot initiated a left turn to draw up beside the loading vehicle. however the left brake lost effect when he applied full rudder and the aircraft collided with the loading vehicle.

84-019 7 10

84/126 ACC MA 26/12/1984 CJT NR TEMUKA At the completion of a spraying run the left wing of the aircraft struck a disused electrical conductor which was attached to a nearby tree.

84-134 7 11

85/92 ACC MA 19/10/1985 CJT NR WAIMATEThe aircraft was engaged in spraying weedkiller on a farm near waimate. during the fourth sortie, at 0745 hours nzst, it collided with an electric power conductor. witnesses found the pilot dead near his aircraft, which was burning fiercely. the probable cause was damage to the aircraft control system sustained in a collision with a wire, which deprived the pilo of control of the aircraft.

85-092 7 12

87/79 ACC MA 18/08/1987 TRS LEVELS VALLEY When visibility was reduced due to sun glare the pilot landed well into a short field. Dew on the grass reduced braking and the aircraft ran into a fence.

87-085 7 13

72/33 ACC MA 2/03/1972 CWX TE PUKEOne blade of a mccauley d2a34c58-bn propeller was reportedly shed when the pilot opened the throttle for takeoff. dsir report carried out. late reporting of this accident and unauthorised interference with the wreckage caused vital evidence to be lost and prevented positive determination of the cause of blade separation.

72-033 8 1




72/55 ACC MA 25/05/1972 CVB WAINUIAfter full power was applied for takeoff a loud bang was heard followed by a loss of thrust. inspection revealed that one propeller blade had separated from the hub as a result of a fatigue fracture of the threaded portion of the blade root. the resulting imbalance caused the remaining blade and hub to separate from engine and damage engine mounts.

72-053 8 2

76/32 ACC MA 18/02/1976 CVA MATAHIWI The aircraft had proceeded about 40 metres along the strip on its takeoff when a propeller blade separated from the hub. the resultant imbalance tore the engine from its mounts and fractured the crankshaft, causing the hub and other blade to separate. the aircraft was brought to a stop half way down the strip. propeller-mccauley model d2a 34c 58n/90at-2

76-029 8 3

72/10 ACC MA 16/01/1972 CWY PUKENUIThe last of 60 tons of lime which, during previous flights, had shown a tendency to hang up, was being sown over steep gullied country. during the last flight the aircraft started to sink and an attempt was made to jettison the load which failed to discharge. the pilot had no option but to stall his aircraft onto a ridge.

72-008 9 1

72/100 ACC MA 17/10/1972 CWT TINUIThe aircraft began to sink when approaching the sowing area. the pilot was unable to jettison the load of damp lime and the aircraft sank into a plantation of pine trees.

72-097 9 2

73/3 ACC MA 3/01/1973 CTT ARARIMUWhen the aircraft failed to attain flying speed the pilot attempted to jettison the load of lime he was carrying but was unable to do so in time to prevent collision with a tree and a fence. it is suspected that the aircraft was overloaded due to a hang-up of part of the previous load.

73-003 9 3




73/82 ACC MA 23/06/1973 CWN NR WAINUI Nearing the end of a steep climb over a ridge en route to the sowing area the aircraft encountered downdraughts and the airspeed decayed rapidly. jettison of the load of lime was initiated but more than half failed to discharge. the aircraft stalled and before recovery could be effected, collided with trees below the ridge line.

73-082 9 4

74/84 ACC MA 15/07/1974 DNB NR TAHEKE The accident was caused by a stall uncorrected soon enough to prevent entry into a spin at a height which precluded recovery before the aircraft struck the ground.

74-082 9 5

74/99 ACC MA 25/08/1974 DMK NR TOKOROA AD

On 4th takeoff aircraft became very tail-heavy on rotation and became airborne in a stalled attitude. pilot attempted to jettison load but unable to do so. aircraft failed to climb out of ground effect. after crossing a small, deep, ravine it impacted heavily on a bank on the far side. all-up weight of aircraft 900 lb above that permitted.

74-098 9 6

74/102 ACC MA 2/09/1974 CWW RAKAU Following a partial power loss during takeoff a heavy forced landing was made in a ploughed paddock as a result of which the nose wheel broke off and the aircraft overturned. partial power loss due to fuel contamination.

74-108 9 7

76/145 ACC MA 12/12/1976 CTT NR CLEVEDONAircraft reloaded with lime and completed takeoff run without becoming safely airborne. in overrun area it cleared ground but despite an attempt to jettison the load struck a small rise immediately afterward sustaining damage to lower left wing which forced pilot to turn towards large tree. as aircraft hit branches, pilot closed throttle and a/d rested on adjacent public highway.

76-142 9 8

77/51 ACC MA 17/03/1977 DMZ MOTERE STN The aircraft sank off the end of the airstrip and the left undercarriage was substantially damaged when it struck a knoll. the pilot flew to hastings and landed without incident.

77-050 9 9




78/96 ACC MA 25/07/1978 DVN TIROHANGA While sowing a damp mixture of fertiliser, part of previous load retained in aircraft's hopper. on next takeoff from level strip aircraft 500lbs overweight. load would not jettison and aircraft sank off the end of the strip, passed through a fence, and bounced over undulating ground before coming to rest

78-096 9 10

79/97 ACC MA 9/08/1979 DNA DARGAVILLE AD

Very wet and muddy conditions considerably increased the empty aircraft's takeoff run. although it became airborne just before the end of the strip the spray booms caught in the tops of some ti tree pulling the aircraft down into the scrub.

79-096 9 11

00/2616 ACC MA 4/08/2000 TRS nr Masterton The aircraft was applying slurry fertiliser on a property north-east of Masterton. The airstrip was wet and soft at the threshold end so the pilot elected to carry light loads of around 400 kg. On the last flight, the aircraft took off into a 10-15 knot south-westerly wind, which was increasing with the arrival of a front. Just after lift-off, the aircraft sank back on to the strip about 30 m from the end, and the soft ground prevented further acceleration.�Beyond the end of the strip was a ravine, and the aircraft struck the far side about 2 m below the lip. The pilot had commenced jettisoning the load as the aircraft sank back on to the ground, and the load was virtually gone by the time of final impact.

9 12

99/921 DEF MI 23/03/1999 TRS MASTERTON ELT failed output terst 10 1

71/32 ACC MA 14/03/1971 CVB TAHEKEROA The pilot was unable to open the hopper door in flight. on return to the strip the aircraft stalled at round-out and landed heavily.

71-029 11 1

99/920 DEF MI 23/03/1999 TRS MASTERTON Wing struts corroded. 14 1


OCC No Code SevDate Time UTC

Reg Location Description Part Defective TAIC Ref Class Total

02/3571 DEF CR 9/12/2002 DOZ Havelock Significant Event. Pilot reported that the rear compartment door broke away. This door then wrapped around the a/c fin causing damage to rudder. The top mounting of the rudder dislodged and rudder collapsed on to starboard elevator. A safe precautionar y landing was made.

Rear Compartment door catch

1 174/28 ACC MA 24/02/1974 CJY Near

DARFIELDAn insecurely fastened oil tank cap resulted in a complete loss of oil during an aerobatic sequence and in the subsequent emergency landing the cap became jammed in the undercarriage operating mechanism thus preventing the undercarriage from being locked down.

74-025

2 103/2283 ACC MA 6/08/2003 RJI Hamilton Ad The Operator reported that the aircraft was doing a touch and

go on runway 08 when it lost power after becoming airborne. The aircraft collided with a boundary fence during the ensuing landing. 5 1

04/2682 DEF MI 11/08/2004 DOZ Mosgiel It was reported that during a routine inspection a crack approximately two inches long was discovered in the compressor casse, on the forward right hand side of the upper engine mount pad.

Compressor Casing

5 204/1931 ACC MA 10/06/2004 ZAA Te Kowhai

AdThe pilot was performing a touch-and-go. After landing the pilot applied full power, the tail lifted, but the aircraft drifted to the right and struck a hedge causing substantial damage.��Sports n Recreation Corporation Certificate: #727.

7 105/1369 ACC MA 29/04/2005 RJI Pukekohe The pilot was ferrying the aircraft from Hamilton to Whangarei

and diverted to Pukekohe East to refuel, On the approach to land the aircraft was low but the pilot's application of power was too late to avoid a collision with a bank at the approach end of the airstrip. 7 2

07/3173 ACC MI 2/09/2007 RZN Mangaweka As the Aircraft was taking off and passing over the brow in the airstrip the pilot had to take avoiding action to miss a sheep. The aircraft skidded and hit an embankment and was written off. The Pilot was not injured.

7 307/4776 INC MI 2/12/2007 WLO Balclutha There was contact between aircraft empennage and loader

truck. The aircraft received substantial damage. 7 4

Annex L: Zlin Z-137T Occurrences 197

OCC No Code SevDate Time UTC

Reg Location Description Part Defective TAIC Ref Class Total

08/996 ACC MI 10/03/2008 VIH Roxburgh A wind gust affected the aircraft on takeoff. The aircraft swung to the left and following corrective action swung to the right colliding with a bank. .

PWilliams

7 505/1427 ARC MI 4/05/2005 RJI New Zealand It is alleged that John Waterson of Super Air submitted a CAA

337 conformity certificate plus a new 2129 radio station form for ZK-RJI covering the installation of Agnav 2 GPS equipment (and a KY96A VHF). He quoted AC43-14 as the acceptable technical data . However AC43-14 states that a differential GPS installation is a major modification and these are excluded from coverage of AC43-14. John Waterson was spoken to by telephone who advised he would either take the equipment off or go to one of the local Part 146 Design Organisations to get the installation approved. 10 1

04/1090 INC MI 28/03/2004 RJI Waimiha While the aircraft was parked on a farm strip with the brakes applied it weather cocked in the wind and the elevator was substantially damaged when it collided with a fence post.

13 105/1019 DEF MI 18/03/2005 VIH North

AucklandSuper Air Ltd reported that the aircrafts L/E skin was found by the pilot to be distorted.

L/E Skin14 1

05/4385 INC MI 11/11/2005 VIH Towai The loader driver failed to latch the rear cargo door which subsequently departed from the aircraft during flight.

15 1

Annex L: Zlin Z-137T Occurrences 198

Annex M Agricultural Aircraft Safety Review

17 March 2008 Page M 1

Summary This report details all the fin related occurrences and defects reported for the FU24-950 series and Cresco aircraft.

Section A covers the FU24 fin failures in detail. Section B covers the FU24 fin defects reported. Section C covers the Cresco 08-600 fin occurrences and defects.

Summary of all failures, defects and occurrences:

Rep

ort

Ref

. Reg. Aircraft Pi

ston

(P) o

r T

urbi

ne (T

) Summary of Details CAA ACU Comment

A1 ZK-CMK FU24A-950

P Corrosion caused separation of fin Unclear whether fin forward attachment or skin failure caused loss of fin

Caused by corrosion

A2 ZK-CZA FU24-950M

P Corrosion caused forward fitting to fail

Caused by corrosion

A3 ZK-BSM FU24-950M

P Corrosion initiated fatigue of the fitting

Fatigue, initiation caused by corrosion

A4 ZK-EGH FU24-950 P Corrosion initiated fatigue of the fitting


A5 ZK-BPY FU24-950M

P Corrosion initiated fatigue of the fitting


A6 ZK-EGV FU24-950 T Corrosion initiated fatigue of the fitting – below skin

Fatigue initiation caused by corrosion, obscured by a/c skin

A7 ZK-EGO FU24-950 P Fatigue failure of LE skin initiated by score marks

Fatigue due to poor practice in application of protective covering.

A8 ZK-DZG FU24-950 T LE skin failed

B1 ZK-EGS FU24-950 P Scratches and scoring around LE skin

Found by AD. Same as scoring on ZK-EGO (A7)

B2 ZK-DUJ FU24-950 T Cracks found on LE and central rib of fin Cause unknown

Not investigated, cause and extent unknown

B3 ZK-EUH FU24-954 P Corrosion on LE skin found Cause unknown

Bad corrosion but no cracks (telecon with a/c Chief



Engineer)

B4 ZK-DUJ FU24-950 T Multiple cracks found on LE skin and internal ribs Cause unknown

Note; same a/c as B2, different (replacement) fin

B5 ZK-JLU FU24-950 T Internal ribs of fin found very broken and cracked Cause unknown

Internal structure – found due to inflight loss of tip cap

B6 ZK-CML FU24-950M

T Crack found on LE Caused by poor fitting of ribs causing high spots on LE skin

2nd rib down. Inititeiuon from poorly formed rib

B7 ZK-EMT FU24-954 T Cracks found on LE skin from working rivets. Chafe marks from dorsal fin also evident

Cracks intited under fastener headss

B8 ZK-EGI FU24-950 P Two cracks found in LE skin Small cracks emanating from bottom of fin free edge

C1 ZK-LTU CRESCO T Large crack found on skin Upper rear fin area – from rudder mount bracket

C2 ZK-LTT CRESCO T Fractured forward fitting. Fin held on by dorsal fin

Cause undetermined

C3 ZK-LTY CRESCO T Fatigue suspected as cause of front fitting mount found broken off

No obvious initiation point detected

C4 ZK-LTH CRESCO T Front fitting found severely cracked

Found by AD

C5 ZK-LTX CRESCO T Crack found on LE. Originally attributed to cable over-tension

On review, not believed to be cable over-tension. crack with unknown cause

C6 ZK-EEL CRESCO T Crack found on LE Corrosion and fatigue suspected

Not investigated

Note: Crescos occurrences (C5 and C6) show some similarities to A8, ZK-DZG



A. FU24 fin failure summary The following is a summary of the 8 known instances where the fin of an FU24 aircraft underwent structural failure, (ceased to provide direction stability and control).

A1. 8 May 1970, ZK-CMK FU24A-950M, Marybank

Occurrence In flight separation of the fin occurred during a ferry flight. Aircraft entered a steep spiral dive to the left before some control could be regained and immediate emergency landing made during which the aircraft was substantially damaged.

The fin had been deflected to the left and ended up restrained to the fuselage only by the pitot head pipes and the rudder. The RH rear spar had failed 4 inches above the attachment bolts, from an area of extensive corrosion that reduced its cross-section by 70%. The forward attachment had evidently failed too, and the fitting was noted as being corroded through 30% of its cross section, but it is unclear if the separation of the fin’s forward attachment was due to failure of the fitting or of the skin?

Source CAA Occurrence 73/70 and TAIC report 73-067

A2. 17 November 1975, ZK-CZA FU24-950M, Tahora

Occurrence In flight separation at the end of a sowing run pilot attempted to pull up but found elevator was jammed in a forward position. Attempted a forced landing, with only ailerons available to manoeuvre and engine power to control rate of descent. The aircraft was substantially damaged.

Forward fitting had failed. The initial failure of the fitting resulted from a weakening of the structure due to corrosive ag chemical acting through discontinuities in the protective paint. Not clear if fatigue was present. Entire fin had twisted around the rear attachment (Spar) and then along with the rudder bent into an inverted V jamming the elevator and rudder.

Source CAA Occurrence75/125 and TAIC 75-119

A3. 4 November 1976, ZK-BSM FU24-950M (Or 300HP?), Pirongia

Occurrence On completion of a sowing run at 90mph (80kts) and 200 ft AGL the pilot commenced a medium rate turn. As the rudder was applied there was a loud bang, control was lost and the aircraft entered a steeply banked diving turn. After closing the throttle the pilot recovered to wings level at a very low altitude. The pilot kept the throttle closed and made a forced landing during which the aircraft went over a ridgeand was



The forward fitting had failed. The fitting was severely corroded. Fatigue not specified in TAIC 76-121 but failed portions sent to DSIR for examination, which suggests there was some reason to examine the fitting closely. Fin remained with aircraft, lying on the left-hand stabilator. Apparently held in place by linen sealing tape along lower edge.

Source CAA Occurrence 76/125, TAIC report 76-121 and interview with John Waterson of Superair.

Airworthiness Directives 16 Nov 1976 DCA/FU24/161 Airworthiness Directive for inspection of forward

fin attachment fitting. Corrosion to be removed and protected or parts renewed as necessary

11 Mar 1977 DCA/FU24/163 Airworthiness Directive for modification of forward fin attachment, per SB ASB/FU/028 or ASB/FU/029.

A4. 30 March 1982, ZK-EGH FU24-950, Maungakaramea

Occurrence Fin forward fitting failed in cruising Flight. Aircraft experienced severe uncontrollable yaw in both directions. Pilot found he had no yaw and limited pitch control. Used engine power to regain some control and carried out an emergency landing.

Rear spar remained attached although twisted through almost 180 deg. Spar caps were able to cope without fracture as the twist was distributed up length of spar. Fin ‘inflated’ by airflow after the skin sheared off from rear spar. The essentially intact fin had rotated through 180 degrees. Leading edge structure remained intact. Resulting drag was so high that pilot was unsure of ability to maintain height with full power, and elected to land immediately. Failure occurred in the cruise with ‘plenty’ of height available which he rapidly consumed while trying to regain control of the aircraft. Initial effect was extreme yaw (looking out the side window at the approaching terrain). Repeated rapid uncontrollable yaw reversals until fin took up its ‘final position’. Yaw produced violent roll. Some control was established using engine torque against roll/yaw. Airflow over the elevator was disturbed such that control became very heavy. Pilot doubted whether he would be able to flare but some control returned as airspeed decreased. Forward fitting failed due to fatigue from a heavily corroded surface. Final failure of the fitting was tensile overload.

Source CAA Occurrence 82/34 and TAIC 83-025 and telecon with pilot Murray Hargreaves 28 Jan. 2007.

Figures A4a through A4d supplied by Murray Hargreaves.



A5. 16 February 1995, ZK-BPY FU24-950M, Ngatea

Occurrence Fin forward fitting failed during a low altitude sowing run. Fin fell clear of the aircraft. Pilot attempted immediate landing but lost control of the aircraft as the bank angle increased towards the left. Pilot seriously injured as the forward fuselage and wing disintegrated. Fwd fitting fracture above fuselage skin but below attachment bolt hole. Fatigue initiated from very small corrosion pit (only just visible in SEM micrograph). Fatigue surface partially obscured by subsequent fretting.

Source CAA Occurrence 95/317

Figures A5a through A5c from CAA occurrence file.

Airworthiness Directives 19 Sep 1995 DCA/FU24/161A Airworthiness Directive for inspection of

forward fin attachment fitting. Inspection for cracks as well as corrosion emphasised.

29 Sep 1995 DCA/FU24/163A Airworthiness Directive for modification of forward fin attachment, per SB ASB/FU/028 or ASB/FU/029, or PACSB/FU/088.

A6. 20 September 2001, ZK-EGV FU24-950, Dargaville

Occurrence The pilot reported that the rudder pedal suddenly locked into a fully deflected position. He managed to land safely at Dargaville where he discovered that the whole tailfin had rotated through 180 (160?) degrees on its remaining bracket and was hanging off. Failure was due to a crack originating from a corrosion pit which was hidden from view when installed on aircraft. Originated below aircraft skin. Pilot Peter Beatty (now deceased ZK-DZG). Telecon with Peter Butcher, a fellow ag pilot who was on hand when the aircraft landed. He was not sure if any photos of the damage were taken, but confirmed it was the fwd fitting and that the fin rotated to at least 135 degrees. Fin was restrained by rear spar but flapped freely back and forth. Peter Butcher had his aircraft (ZK-EME) checked the next day and found suspected crack initiated from chafing lock wire.

Discussions with PAC suggest that fatigue margin of original design may have been reduced by anodising, which was introduced to counter the corrosion problems that were experienced. Cad plated steel item is made to same dimensions so has higher static and fatigue strength margins, as well as good corrosion resistance. Existing DCA/FU24/163 directed that -1 (al) OR -3 (steel) fittings be installed. This AD cancelled and replaced by DCA/FU24/172 which directs that -3 fittings are to be installed and inspected at 12 month intervals.

Source CAA Occurrence 01 3269 and Telecons with Mike Chubb, Peter Butcher and Murray Hargreaves.



No photographs available but describes as essentially similar to incidence 4, ZK-EGH.

Airworthiness Directive 25 Oct 2001 DCA/FU24/172 Airworthiness Directive for replacement of

forward attachment fitting and inspection of fin leading edge.

A7. 18 April 2002, ZK-EGO FU24-950, 6 SSE Masterton

Occurrence Fatigue failure of the skin immediately aft of the forward attachment bulkhead. Fatigue initiated from score marks left in the skin during LE rubber installation unknown number of hours previously. Crack propagated up the left-hand side of the LE skin and approx 1 inch down the right-hand side. Fin fell sideways onto left hand stabilator, as well as rotating to the left, fracturing the right-hand rear spar cap then the web and finally the left-hand spar cap before falling from the aircraft. Rear spar shows evidence of bending left and forwards see figure 10. The breakup sequence bent the rudder into an inverted V which wedged in the stabilator restricting pitch control for at least some of the subsequent flight. Pilot was unable to manoeuvre the aircraft clear of a ridge and was killed in the post crash fire.

Sources CAA Occurrence 02/1167, Accident report

Figures A7a through A7h.

Airworthiness Directive 26 Apr 2002 DCA/FU24/173 Emergency Airworthiness Directive for

inspection of forward fin structure. If any structure is found cracked, it must be repaired before further flight and the CAA notified.

A8. 22 November 2005, ZK-DZG FU24-950 Walter Turbine Conversion, Whangarei

Occurrence Aircraft crashed in dense bush during a ferry flight in deteriorating weather. The pilot and crew member were killed and the aircraft destroyed. The fin was found amongst the wreckage but witness marks on the fuselage and stabilator indicated that it had fallen onto the left stabilator and heavily contacted the fuselage prior to the impact (in-flight). The Fwd fitting was intact and remained attached to the fuselage. The Forward bulkhead and several inches of LE skin remained attached. The fin had failed through the LE skin approximately 6 inches above the forward attachment. The rear attachment had also failed via fracture of the rear spar. The LE failure was characterised by both sudden tensile overload and a small section on the extreme



leading edge that exhibited a polished and/or fretted appearance. Metallurgical analysis of the extreme LE indicated fatigue cracking that was heavily obscured by subsequent damage (cf incident 5, ZK-BPY) . The rear spar failure was the result of sudden tensile overload. It appears to have fractured RH spar cap first, then the web followed by LH spar cap. Similar to ZK-EGO there are indications that the spar was twisted to the left and slightly forward, from comparison of the distortion on the spar caps and web, figure A7c.

Source: CAA Occurrence 05/3727, Accident Report

Airworthiness Directives 31 May 2007 DCA/FU24/176A Airworthiness Directive for inspection and repair

of fin focussing on fin leading edge.

28 Jun 2007 DCA/FU24/176B The content of these Airworthiness Directives (B and C) were revised to clarify the intent of the above (A). 27 Sep 2007 DCA/FU24/176C



Figure A4a: ZK-EGH, FU24-950, Maungakaramea

Figure A4b: ZK-EGH, Fin twisted almost 180 deg.



Figure A4c: ZK-EGH, Post emergency landing.

Figure A4d: ZK-EGH, Rear Spar to the left, fin leading edge to right.



Figure A5a: ZK-BPY, FU24-950M, Ngatea

Figure A5b: ZK-BPY, Fwd fitting fatigue through, section below bolt hole, not lug min x-section.



Figure A5c: ZK-BPY, Note clean departure of Fin, found 500m from crash landing.

Figure A7a: ZK-EGO, FU24-950, Masterton



Figure A7b: ZK-EGO, Fin fwd attachment fitting, fwd bulkhead and extreme LE skin attached to aircraft.

Figure A7c: ZK-EGO, Rear Spar looking aft, spar has twisted to port and slightly forward before fracturing.



Figure A7d: ZK-EGO, Rudder and witness mark in port stabilator.



Figure A7e: ZK-EGO, Witness mark on rear fuselage, rudder post pulled fwd and to port.



Figure A7f: ZK-EGO, Rudder wedged in stabilator damage

Figure A7g: ZK-EGO, Note distortion on fin to fwd attachment. Left hand skin was already failed (fatigue from knife marks). The starboard lower section of skin has been pulled to starboard as it attempted to restrain the fin leading edge as it buckled to port. Compare the residual lean angle of the right hand skin with the deformation evident on the left hand side of the forward remnant (figures A9 & A10). This



suggests that the fin has started to buckle to port while still remaining partially attached to the fwd portion.

Figure A7h: ZK-EGO, Close up of Figure A7g.


17 March 2008 Page 17Error! No text of specified style in document.

B. Table of FU24 fin defects

In addition to the in-flight failures above, the following defects have been reported for the FU24 vertical stabilisers.

Key Occurrence no Work Request

Code Severity Date Registration Location Description Model Part defective Part no

B1 02/1578 2/SAI/2184

DEF MI 16/04/2002 EGS Fielding Investigation of fin IAW DCA/FU24/173 found scratches and scoring around skin.

NZ Aerospace FU24-950

Forward skin of Fin 242308-2

B2 03/1964 4/SAI/42

DEF MI 2/07/2003 DUJ Masterton Several cracks were found in leading edge and central rib of the tail fin of a Walter powered Fletcher when it was removed for painting.


Tail fin

B3 03/2967Nil W/R

DEF MI 26/09/2003 EUH Wanganui Bad corrosion was found on the vertical fin leading edge skin, in the area of the front mount bulkhead, during the aircraft's first 100 hour inspection.


Corrosion

B4 03/3295 Nil W/R

DEF MI 13/11/2003 DUJ Masterton Multiple cracks were found in the skin and internal ribs of the airframe. This is a Walter Fletcher.


Multiple cracks

B5 06/556 6/SAI/1438

DEF MA 8/02/2006 JLU Masterton The internal ribs of the Walter Fletcher vertical stabiliser were found to be broken and cracked.


Internal Ribs 242340

B6 06/2830 7/SAI/239

DEF MI 14/07/2006 CML Hamilton A crack was found on the fin leading edge skin starboard side between the leading edge and middle rib doubler P/N 242337R. The crack was on the doubler centre line in a horizontal direction and about half an inch long.

Fletcher FU24-950M

Leading edge skin 242308 - 2

B7 06/35377/SAI/561

DEF MI 7/09/2006 EMT Palmerston North

Whilst complying with DCA/FU24/ 176 cracks were found on the leading edge skin from working rivets. Chafe marks made by the dorsal fairing were also evident.


Leading edge skin and ribs

B8 06/3543 7/SAI/565

DEF MI 20/09/2006 EGI Gore It was reported that the aircraft was undergoing 4 yearly inspection when the leading edge fin was found to have crack in it.


Leading Edge Fin 242308-2



Further details about the FU24 fin defects

B1. 16 April 2002, ZK-EGS FU24-950, Fielding CAA SIU database: As a result of finding, new LE skin is fitted.

CAA WR 2/SAI/2148: The investigation has been completed as far as possible. No further CAA Action is anticipated. Ian Stobba 19 Jun 2002.

B2. 2 July 2003, ZK-DUJ FU24-950, Masterton CAA SIU database: Cracks found in fin leading edge.

CAA WR 4/SAI/42: Spoke to Lew Dayman of Air Services Ltd. He will take up with Byron Knight who initiated the defect report and hopefully submit information which will enable event to be closed. Discussed with Ian Stobba, agreed that in view of the time now elapsed, chances of actually receiving any further. The investigation has been completed as far as possible. No further CAA Action is anticipated. Mike Baker 20 Oct 2004.

B3. 26 September 2003, ZK-EUH FU24-954, Wanganui CAA SIU database: The skin area was repaired. Form 005D submitted by Rob Hartnell of Wanganui Aero work. Nil W/R or log entries.

B4. 13 November 2003, ZK-DUJ FU24-950, Masterton CAA SIU database: All cracked parts were replaced.

Nil W/R or log entries.

B5. 8 February 2006, ZK-JLU FU24-950, Masterton CAA SIU database: The vertical fin top fibreglass fairing was found missing while the aircraft was operating. A serviceable fairing was fitted that became loose not long after being fitted. An inspection of the fin top rib with the fairing removed showed the rib completely broken across the rear reveal. The fin was removed and a serviceable one fitted. The trailing edge skin was removed and it was found the second rib down was completely broken across the rear reveal and the third rib down was cracked across the rear where attached to the spar. The log books did not show any major work had been carried out on the vertical stabilizer since the Walter conversion on the 17th August 2000. There were no signs of working rivets on the exterior of the fin and there is no access to the interior structure apart from the top fairing. The aircraft was being maintained to Part 43 Appendix C and did not have any major inspection programme in place.

CAA WR 6/SAI/1438

Figures B5a and B5b.



B6. 14 July 2006, ZK-CML FU24-950M, Hamilton CAA SIU database: Investigation revealed the fin had been overhauled only 230 hours previously. During the overhaul new nose ribs had been fitted to a new leading edge skin. The poor fitting of several of these ribs into the leading edge skin with high spots caused the crack, figures B6a and B6b. Several other high spots on the leading edge skin were also apparent.

CAA WR 7/SAI/239: SIU discussed defect with Super Air, viewed defective parts and associated work sheets. State changed to closed as investigation completed as far as possible. Ian Stobba 27 Sep 2006.

B7. 7 September 2006, ZK-EMT FU24-954, Palmerston North CAA SIU database: An approved repair scheme was authorised by a design organisation for six months while a new type fin is being designed. The repairs included a new leading edge skin and ribs.

CAA WR 7/SAI/561: Fletcher -Stallion with 'distressed' fin. Under inspection/repair at Fieldair, arrow indicate working rivets, on closer inspection several found to be cracked. Cracks emanating from under rivet head NOT from holes which is an indication of skin panting/buckling as opposed to tension loads which tend to form cracks from rivet holes. Also fretting where dorsal extension attaches.

State changed from Assessment to Closed. The investigation has been completed as far as possible. No further CAA Action is anticipated. Ian Stobba 2 Oct 2006.

From 005D: Failure of the two upper rib attachment rivets caused the skin to be unsupported, allowing flexing especially under side airloads causing the skin to start cracking. Rib p/N 242343 and 24320 and skin P/N 242308-2 replaced.

See photographs (figures B7a through B7d), cracking at upper edge and from rivets attaching it to next panel. Most of the LE to rib rivets working, oval holes, extensive chafing from dorsal fin extension on LE.

B8. 20 September 2006, ZK-EGI FU24-950, Gore CAA SIU database: While carrying out the airworthiness directive DCA/FU24/176, two cracks were discovered in the leading edge of the fin. The leading edge skin was replaced. See photos (figures B9a through B9c), cracks have initiated from free edge of skin above uppermost rivet attachment to the front bulkhead.

CAA WR 7/SAI/565: State changed from Assessment to Closed. The investigation has been completed as far as possible. No further CAA Action is anticipated. Peter Kirker 30 Jun 2007.



Figure B5a: ZK-JLU, FU24-950, Masterton

Figure B5b: ZK-JLU, FU24-950, Masterton



Figure B6a: ZK-CML, FU24-950M, Hamilton. Fin LE crack.



Figure B6b: ZK-CML. Crack in relation to base of fin.



Figure B7a: ZK-EMT, FU24-954, Palmerston North



Figure B7b: ZK-EMT, FU24-954, Palmerston North

Figure B7c: ZK-EMT, FU24-954, Palmerston North

Figure B7d: ZK-EMT, FU24-954, Palmerston North



Figure B8a: ZK-EGI, FU24-950, Gore



Figure B8b: ZK-EGI, FU24-950, Gore



Figure B8c: ZK-EGI, FU24-950, Gore



C. Table of Cresco 08-600 fin occurrences and defects

Key Occurrence no Work Request

Code Severity Date Registration Location Description Model Part defective Part no

C1 00/1690 0/SAI/1903

DEF MA 22/05/2000 LTU NAPIER The vertical fin skin had a 6 inch long cracked from adjacent the top of the rudder mount bracket. It is suspected excessive loads have been imposed on skin.

Pacific Aerospace Cresco 08-600

Skin Cracked 08320014

C2 00/1769 0/SAI/1883

DEF CR 26/05/2000 LTT MATAMATA

Significant Event. During topdressing operation, loader driver noticed vertical fin movement during taxi up to loading area and previous take-off. Examination of area revealed fractured vertical stabiliser Forward fitting. Forward location only held by dorsal fin attachment screws most of which were ripped out.


fitting - forward fin attach.

243017-2

C3 04/1305 4/SAI/1706

DEF MI 21/04/2004 LTY Wanganui It was reported that during the 100 hour inspection the vertical fin front mount was found broken off.


Front Mount 243017-2

C4 04/1803 4/SAI/1949

DEF MA 31/05/2004 LTH Wanganui It was reported that whilst changing the fin mount from aluminium to steel, the original fitting was found cracked one third to half way across.


Front Mount 243017-2

C5 05/2942 6/SAI/464

DEF MA 24/08/2005 LTX Napier During a scheduled inspection of a Cresco aircraft the fin leading edge skin was found to be cracked at the top of bulkhead P/N 242305-2 attachment.


Fin Leading Edge 08-32001-4

C6 07/1266 7/SAI/1979

DEF MI 2/04/2007 EEL Taieri Fin leading edge skin found cracking from top of cut-out area for PN: 242305-2 bulkhead.


Leading Edge Skin 242308-3



(Last two Cresco occurrences were the ones that prompted DCA/Cresco/13 in December 2007, photos and 005 forms supplied to Ken Mathews at TAIC.)



Further details about the Cresco 08-600 fin occurrences/defects

C1. 22 May 2000, ZK-LTU Cresco 08-600, Napier (00/1690) CAA SIU database: The manufacturer has been advised and repair scheme data obtained.

CAA WR 0/SAI/1903: State changed from Assessment to Closed. Cracking of vertical fin is a long-standing problem with Cresco's. No further investigation at this point. PG 18 Jan 2001.

No further details available (no hard copies, nothing in DMS).

C2. 26 May 2000, ZK-LTT Cresco 08-600, Matamata (00/1769) CAA SIU database: No corrosion evident and lockwire NOT around fitting. The manufacturer was advised and the fitting forwarded for analysis.

CAA WR 0/SAI/1883: State changed from Assessment to Closed. Manufacturer unable to determine cause of failure as failure surface too badly damaged. PG 16 Jan 2001.

No further details in DMS.

C3. 21 April 2004, ZK-LTY Cresco 08-600, Wanganui (04/1305) CAA SIU database: Fatigue is suspected (no corrosion or other stress raiser). The aircraft had 3,500 hours. One previous failure at 4,800 hours. PAC has an optional steel fitting which has been standard production since s/n 029. PAC has published a SB calling for reduced inspection intervals with replacement of any aluminium fittings with a steel fitting by 3,000 hours (or within 150 hours if that is already reached). The SB is the subject of AD DCA/CRESCO/7 (27 Apr 2004).

CAA WR 4/SAI/1706: Discussion regarding the importance of getting an emergency AD from experience with the same Fletcher fitting. State changed from Assessment to Closed. Investigation completed. AD issued. PG 26 May 2004.

No further details in DMS.

Airworthiness Directive 29 Apr 2004 DCA/CRESCO/7 Airworthiness Directive for inspection and

replacement of fin forward attachment.

C4. 31 May 2004, ZK-LTH Cresco 08-600, Wanganui (04/1803) CAA SIU database: It is recommended that all aluminium fitting be removed. Note: CAA investigations show there are only three aircraft in New Zealand and two in Australia with the aluminium fitting. All these aircraft have more than 3,000 hours and are therefore subject to the inspection/replacement requirements of the ADs. (Australia has raised a similar AD.)



CAA WR 4/SAI/1949: State changed from Assessment to Closed. The CAA investigation has been completed and no further action is required as all aircraft will have the steel fitting in accordance with the AD. PG 04 Jun 2004.

C5. 24 August 2005, ZK-LTX Cresco 08-600, Napier (05/2942) CAA SIU database: The fin leading edge skin was repaired with an approved repair scheme and the aircraft returned to service. An investigation found the possible cause may have been the cable deflector modification PAC/CR/0051 that was installed could have had the cable tension to high and therefore exerting a load on the fin. It was also found there does not appear to be any maintenance instructions supporting this modification. This matter is being taken up with the manufacturer.

CAA WR 6/SAI/464: State changed from Assessment to Closed. The investigation is complete and all factors such as confirmed rule non-compliance, causal factors and corrective actions have been entered on the Data Base. Ian Stobba 04 Oct 2005.

005D Cause: Fatigue, Possible cause being Wire cutter cable adjusted too tight. 005D Action taken: Fin Repair C/Out IAW FC-55-009, Wire Cutter Cable adjusted, Tech Data requested from Manufacture.

Figures C5a through C5e.

C6. 2 April 2007, ZK-EEL Cresco 08-600, Taieri (07/1266) CAA SIU database: Corrosion Fatigue. Leading edge skin replaced. Spoke with the submitter Dave Patrick. He said that this crack is not readily inspectable as it is in the dorsal fin area. We discussed how critical this was and he said if it was the Fletcher it would be. However it was not like the Fletcher as there is a different structural design. This is secondary structure where in the Fletcher is primary structure.

CAA WR 7/SAI/1979: State changed from Assessment to Closed. The investigation has been completed as far as possible. No further CAA Action is anticipated. Steven Walker 20 Apr 2007.

005D Cause: Corrosion/fatigue. 005D Action taken: Leading edge skin replaced.

Airworthiness Directive

Figures C6a and C6b.

12 Dec 2007 DCA/CRESCO/13 Airworthiness Directive for inspection of fin leading edge.



Figure C5a and C5b: ZK-LTX, Cresco 08-600, Napier



Figures C5c, C5d and C5e: ZK-LTX, Cresco 08-600, Napier



Figure C6a: ZK-EEL, Cresco 08-600, Taieri

Figure C6b: ZK-EEL, Cresco 08-600, Taieri

Appendix N Agricultural Aircraft Safety Review

Page N1

FU24 Vertical Fin Comparison During the FU24 Fin Engineering review, the Agricultural Aircraft Safety Review and the compilation of Paper DW1165505-0, it was necessary and at times instructive to consider the design details of the FU24 vertical fin. This document summarises the FU24 fin design details and compares them with other light single engine aircraft.

The FU24 fin is unusual in having a single forward attachment point but not unique. The Pacific Aerospace Cresco was developed from the FU24, and shares many components including the single fwd attachment point and the leading edge. The Cresco fin benefits from the addition of a dorsal fin, protecting the critical lower leading edge and providing a certain amount of back up structure, (although it is secured to the fuselage with blind rivets and to the fin with riv-nuts which are not normally used for structural loads). The Cresco also has a single sheet of aluminium running vertically up the fin attached to the first lap joint. By comparison to the FU24 it introduces a second structural member to the leading edge assembly, item 47 in figure 1 below.

Figure 1 Cresco Fin Illustrated Parts Catalogue


Page N2

Single Forward Attachment Designs The Alpha R2000 aircraft have a similar fin design to the FU24 with a single attachment point and unreinforced load bearing leading edge. Refer Figure 2. The R2000 is designed for private operations with a 120-160HP engine. The Zenith CH200 range of homebuilt aircraft uses a similar design. The designer of the Zenith series was Chris Heintz, used to work for Avions Pierre Robin and was involved in the design of what became the Alpha R2000. The Zeniths are designed to fly with 80-120 HP.

Figure 2 Alpha Aviation Drawing

Figure 3 Alpha R2160


Page N3

The Thorp T-18 Homebuilt has a similar forward attachment point, as it was designed by John Thorpe who originally designed the Fletcher FU24. The Thorpe T-18 was designed around the 100 HP 0-200 but is commonly fitted with 160HP O-320. Figure 4 is an external view of T-18 Note the cranked wing and the fin which is similar in overall shape as well as well as internal structure to the FU24.

By comparison the Cherokee PA28 series, which John Thorpe also designed, retains the single forward attachment but the leading edge now has three structural components where the FU24 only has one, refer Figures 5,6 &7.

Figure 4 Thorpe T-18 Homebuilt

Figure 5 Piper PA28-180C (Cherokee Archer)


Page N4

Figure 6 Cherokee Fin Attachment Detail

Figure 7 Cherokee Fin Structure


Page N5

Conventional Fin Designs In comparison to the few aircraft mentioned above, the more conventional approach is to provide two forward attachment points and internal structure, in addition to the load bearing skin. The homebuilt Sonex is an example of this construction.

Sonex Two seat homebuilt aircraft Engine: Aero-Vee 80HP (Volkswagon derivative)

Sonex fin internal structure, stressed metal skin to be attached. Forward attachment via two bolts in corners of triangular attachment plate. Forward spar consists of ‘C’ section channel.

Figure 8 Sonex Homebuilt

Figure 9 Sonex Fin Internal Structure


Page N6

The Cessna range of single engine aircraft all have very conventional fin designs.

Cessna 152 Private /Training aircraft 1640 lbs MAUW Lycoming O-235, 115 HP

Design Features

• Two forward attchments

• Forward and rear spars

• Forward spar has

a part span doubler, intercostal ribs.

Cessna 182

Utility Aircraft MAUW 2600lbs (check) Engine Lycoming 0-540 250HP

Design Features

• Two forward attachments

Figure 10 C-152 Fin Structure


Page N7

• Forward and rear spars

Cessna 188A Agwagon (and Cessna 180/185).

Agricultural aircraft, MAUW 4000lbs (check) Engine Continetal O-520 240HP

Design Features”

• Forward spar.

• Two forward

attachment points and additional attachment of dorsal extension.

Figure 11 C-182 Fin Structure

Figure 12 C-A188 Fin structure


Page N8

Cessna 208 Caravan Utility Aircraft MAUW: Engine P&W PT6A-34, 750SHP

Design Features:

• Two forward attachment

points.

• Forward spar,

• Extra nose ribs.

Figure 13 Cessna 208 Caravan


Page N9

Summary The FU24 has an unusual fin design. It is attached to the aircraft in just three places and as such relies on the integrity of all three attachment load paths. Structurally it is analagous to a mast supported by three stays or a three legged stool. Both of these are perfectly strong stable structures but vulnerable to a failure of any single component.

The detail design of the FU24 fin where the loads pass from one component to the next means that from a structural integrity point of view, failure of one component in the load path is as serious as any other. This underlies the concept of the fin as a system and was the rational behind the grouping of fin defects for the purposes of analysis in the Agricultural Aircraft Safety Review.

Although the single forward attachment point has been used on the Cherokee and Cresco, their leading edge structures consists of more than one piece of material. Having an assembly of two or more pieces prevents a crack from growing and compromising the whole structure. In this way the Cresco (2 piece) and Cherokee (3 Piece) are less vulnerable than the FU24. The single forward attachment with single piece leading edge has been used on light aircraft of 100-200HP, but it is not a popular design solution.

Most utility aircraft, including the Cessna single engine range, use a conventional fin design with two forward attachments and internal structure within the leading edge assembly. The fin design of the Cessna Agwagon A-188 is noteworthy as it is designed to operate in the agricultural role. The Cessan 208 Caravan is a turbine powered utility aircraft, with a similar engine and operating weight to the Cresco.

Annex O to Agricultural Aircraft Safety Review

1

Acceptable Climb Performance Introduction The Agricultural Aircraft Safety review detailed how the requirement to meet a minimum angle of climb had been omitted from the overload provisions of Part 137. The previous regulation of agricultural operations had required the aircraft to be capable of achieving climb gradient of at least 6% at the weight and conditions under which it was to be operated. The FAA document CAM 8 used to require a minimum of 350 fpm or 8 xVs whichever was higher.

To improve the safety of agricultural operations in New Zealand, the rules governing operation at weights greater than the aircraft’s maximum certified take-off weight (MCTOW) need to ensure a certain performance margin is available. Some performance margin is necessary, not just for the obvious need to out climb terrain and obstacles, but also to permit the aircraft to manoeuvre. The following section explains the requirements for performance margin in relation to manoeuvrability and consider the special case of downhill take-offs. Both of these factors need to be considered in the selection of a minimum climb performance for agricultural operations. This section does not calculate what the minimum climb performance should be. That decision should be reached in consultation with experienced industry member and backed by flight testing. The following is intended to aid that process.

Manoeuvrability To turn an aircraft or any other vehicle requires the application of a force at 90 degrees to its direction of motion acting, inwards towards the centre of the turn. The obvious example is a tennis ball on a string, where the string provides the inwards force to keep it travelling in a circle. Road vehicles rely on the front wheels to provide an inwards component of force when they are angled in the direction of the turn.

Figure :. Tennis ball and string in circular motion

Figure 2: Aircraft in straight and level flight

Direction of travel without string force

W

LiftLift

Total Lift


2

An aircraft in straight and level flight is represented in Figure 2. The aircraft is flying away from the viewer. The lift generated by each wing (blue) combines to provide a total lift force that is equal in size and opposite in direction to the weight force. The aircraft continues straight ahead neither climbing nor descending.

To make a balanced turn, aircraft (and birds), roll to angle their lift vector toward the direction of the turn. As shown in the figure 3 this provides an inwards component, and accelerates the aircraft in the intended turn direction. Without the inwards force it would continue straight ahead.

Figure 3: Aircraft turning left

As the total lift vector is tilted, the component acting upwards (red) is decreased. If this was not compensated for, the aircraft would start descending as the upwards component would no longer balance the weight due to gravity (W), which remains unchanged. To avoid sinking in the turn the pilot increases the aircraft’s angle of attack slightly to increase the total lift vector, until the upwards component once again equals the aircraft weight. The increase in angle of attack produces an increase in drag so the engine power needs to be increased to prevent the speed reducing and decreasing the lift again. In gentle turns at light weight where the angle of bank is small and the turn duration is short, the loss of height and speed may be small enough to neglect. However, if flying only slightly above the stall speed, and/or close to the ground, they become important.

The steeper than angle of bank, the more pitch, and power needs to be applied to maintain height. At a given speed, the aircraft’s radius of turn is proportional to its angle of bank. Tight turns require steep bank angles, which require more power to perform without height loss. Therefore the rate at which an aircraft can perform a level turn is proportional to how much extra power is available from that required in straight and level flight, at the given speed. This is known as the ‘excess power’ for that speed. At an extreme, an aircraft that was using full power just to maintain height at a speed just above stalling would not be able to turn at all, as without additional power to compensate for the tilted lift vector, it must sink or slow down in the turn. If already close to stalling it cannot keep flying if it slows down.

The ‘excess power’ available at a given speed is difficult to calculate. While the engine rated horsepower is known, and the thrust the propeller produces can be

W

Total Lift


3

calculated (thrust decreases with airspeed), the drag produced by the aircraft at a given weight and speed (hence angle of attack) is difficult to predict.

However the amount of excess power also determines the aircrafts rate of climb. At a given airspeed, the rate of climb is proportional to the difference between the thrust available and the airframe drag produced at that speed. Rate of climb is relatively simple to measure and provides an indication of the aircraft’s excess power. Therefore the attainable rate of climb also provides a measure of the aircrafts ability to manoeuvre around obstacles in the horizontal plane as well as its ability to climb over them.

Safe agricultural operations require adequate climb performance and manoeuvrability, and hence a certain amount of excess power. The easiest way to measure the excess power is to measure the aircraft climb performance. Therefore the selection of a minimum climb performance acceptable for agricultural aircraft operations, needs to assess the rate of climb and the maximum bank angle (and turn radius) that is attainable at the selected weight.

Downhill Take-offs Another factor that needs to be accounted for in NZ agricultural operations is the effect of downhill take-offs. Agricultural operations in New Zealand often take place on sloping airstrips, due to the scarcity of substantial areas of flat land. Take-offs are invariably made in the down-slope direction to take advantage of gravity to accelerate to flying speed. While the slope helps the aircraft to accelerate, it also means that immediately after take-off the aircraft is actually descending. The following is a means of calculating the initial rate of descent.

Knots Feet Per Second km/hour

60 101.2 111 65 109.7 120 70 118.1 129 75 126.6 140 80 135 148

Figure 4

Figure 5

Q

Vd

Vr

Vh


4

The descent velocity in feet per second can be calculated using

Descent Velocity = Sin Q x Vr

where Q = slope in degree from horizontal

Vr = Velocity at takeoff in feet per second

Multiplying the result by 60 gives the more customary units of feet per minute (fpm).

Gradient Grade % Slope (degrees)

ROC (fpm) V r 60 kts

ROC (fpm) V r 70 kts

1:20 5% 2.86 - 303 - 386

1:15 6.67% 3.81 - 404 - 514

1:10 10% 5.71 - 604 - 770

1:5 20% 11.31 - 1191 - 1518

Figure 6

The table in figure 6 shows that take-off even from a moderate 1 in 20 sloped airfield results in an initial descent velocity of over 300 fpm. At the upper end, steeper slopes and higher rotate speeds produce initial rates of descent of over 1000 fpm.

Unfortunately the selection of a minimum acceptable rate of climb is not as simple as saying it should exceed the rate of descent attained immediately after takeoff.

Consider an aircraft that has climb rate of 100 fpm at its best climb speed of 80 knots. If the aircraft has accelerated to best climb speed while descending at 500fpm, it can commence climbing at 100fpm, as long as it maintains 80 knots. To pull out of the descent and establish the climb the aircraft needs to pitch upwards. If the aircraft pitches up too rapidly, the speed will decrease below 80 knots and the rate of climb will decrease. While pitching up from the descent to the climb the aircraft travels along an arc. The radius of the arc is proportional to the rate at which the aircraft can pitch up without losing speed. The rate it can do this is proportional to the excess power at 80 knots. If the excess power is small, the radius will be large, and descent will continue for longer before the climb is established.

Therefore ability to arrest the rate of descent is once again proportional to excess power. As described earlier, excess power is most easily quantified by measuring the rate of climb at a given aircraft weight.

Conclusion Selection of an acceptable climb rate for agricultural operations beyond MCTOW should take into account the rate of descent that can develop during downhill takeoffs. In addition consideration should be given to the aircrafts ability to pull up from the descent after takeoff on anticipated slopes. Its ability to do this will be proportional to its excess power. This may be best established by test.


5

Figure 7: Cresco taking off downhill. Dave Wareham photo.

Figur 8: FU24 Downhill takeoff in South Island, Jim Nimmo photo.

Annex P to Agricultural Aircraft Safety Review

1

Landing Gear Considerations Introduction Chapter 4 Section 2 of the Agricultural Aircraft Safety Review considered the high rate of landing gear failures amongst New Zealand produced agricultural aircraft. A contributor to this failure rate is the practice of operating at the Part 137 overload weight which is approx 30% higher than the weight used for design and certification of the landing gear. Design of a reasonably reliable landing gear for NZ conditions requires some consideration of the loads likely to be encountered in service. Only if the service loads are correctly anticipated can the design and certification requirements be correctly specified. The obvious modification to the certification requirement would be to certify the landing gear for operation at the selected agricultural overload weight (i.e. MCTOW+30%). However there are two other factors unique to agricultural operations that this approach overlooks, uphill landings and the disposable load effect.

Uphill Landings On landing uphill another calculation has to be performed. Normal undercarriage design loads are detailed in Federal Aviation Regulation 23.473. The full set of requirements is complex but the calculation starts with the requirement that the landing gear be capable of withstanding the loads generated by contacting the ground with a rate of descent equal to:

Vd = 4.4(W/S)1/4 {FAR 23.473}

where W = Landing weight , S = wing area, (W/S is the wing loading in lbs/in2)

For the FU24 at the Part 137 weight of 6367 lbs and a wing loading of 24lbs/sq in, this calculation produces a descent velocity of 1584 fpm. (15.5 knots) FAR 23.473 then states that the rate of descent need not exceed 10 fps which is equal to 600fpm.

This then is the standard design condition for FAR 23 light aircraft. The landing gear should be strong enough to withstand the loads seen by the undercarriage if the pilot sets the aircraft up in a 600fppm glide, and flew all the way down without the usual round out and flare. Subsequent section of FAR 23 deal with calculating the resulting deceleration ‘g’. Long travel ‘soft’ undercarriage can accept that rate of descent without imposing large loads on the airframe, while short travel undercarriage with firm springs will have to arrest the 600fpm descent in fewer inches of travel and produce a greater deceleration and thus loads into the undercarriage and supporting structure.

All of this presumes a descent onto a level runway, with a rate of descent perpendicular to the runway. In NZ agricultural operations, landing s are routinely made up slope. The effect of an up slope is to increase the apparent rate of descent, from that shown on the aircraft vertical speed indicator (VSI).


2

G = slope of the ground relative to horizontal. s = aircrafts glide slope, below horizontal Vd = rate of descent indicated on aircraft VSI. Vref = Aircraft approach speed Vt = aircraft approach speed tangential to the ground Vp = aircraft approach speed perpendicular to the ground.

Figure 1: Uphill landing

When landing on a level runway, Angle G = zero and Vp = Vd which for design purposes can be taken as the 10fps/600 fpm from FAR 23.473.

When the ground slopes up, the glideslope is effectively steepened to angle (s+G) and the speed perpendicular to the ground becomes Vp, which is larger than Vd the rate of descent shown on the aircraft’s VSI.

The new velocity perpendicular to the ground is :

Vp = sin(G + s) x Vref

The increment in apparent descent velocity perpendicular to the ground is:

dVp = sin( G )x Vref

For the FU 24 with a Vref of 55 kts, a range of runway slopes gives the following increases in apparent descent velocity,

Slope Grade % Angle G Descent velocity increment (fps)

V ref =55 knots

1:20 5.00 2.86 4.64

1:15 6.67 3.81 6.19

1:10 10.0 5.71 9.25

1:5 20.0 11.31 18.24

G

Vds

Vt Vp

G

V ref


3

Figure 2: Descent Velocity Increments

Recalling that the maximum rate of descent required by FAR 23.473 was 10 fps, even a relatively gentle 5% up slope increases the rate of descent by more than 40%. from that encountered on a level runway.

In day to day operation on sloping strips experienced pilots would compensate and adjust the flare until they are landing almost parallel to the up slope with a slight rate of climb at touchdown. But most pilots operating FAR 23 aircraft also flare and achieve landings with a minimal rate of descent. The point of a certification standard is that is intentionally a worst case. Designing FAR 23 aircraft to withstand the loads of a 600 fpm descent, which they may only experience once in their lifetime, gives them sufficient static strength to withstand a long service life at the much lower everyday landing loads.

Therefore, although most agricultural pilots will flare sufficiently to compensate for the slope, to provide NZ agricultural aircraft with the same confidence in their landing gear as regular FAR 23 aircraft they probably need to be certified to a load 40%-50% higher than the FAR 23.473 case.

Disposable Load Effect As discussed in Chapter x, the choice of landing weight at which these calculation is s performed also becomes important for NZ agricultural operations, as FAR 23 usually assumes the landing weight is not less than 95% of the take-off weight. If that is true the 600fpm landing loads exceed anything likely to be encountered during taxiing or take-off. But if the take-off weight is 40% greater than the landing weight the protection provided by that assumption is no longer present. In that case FAR 23.473 paragraph g) states:

g) No inertia load factor used for design purposes may be less than 2.67, nor may the limit ground reaction load factor be less than 2.0 at design maximum weight, unless these lower values will not be exceeded in taxiing at speeds up to takeoff speed over terrain as rough as that expected in service.

This means that unless it can be shown otherwise,1 the aircraft can be expected to experience acceleration of up to 2 G when encountering to bumps in the runway at speeds up to take-off speed. This requires that the landing gear be designed to withstand a force sufficient to accelerate the aircraft at take-off weight upwards at 2G. This needs to be assessed for NZ agricultural operations as, the 2G acceleration at Take-off weight may be more severe than the 600fpm landing at landing weight.

Conclusion The effect of uphill landings on ground closure speeds and the effect of the marked difference in weights at takeoff and landing are two of the factors that need to be assessed during the engineering assessment of the aircraft’s ability to operate at weights above it’s maximum certified takeoff weight. Failure to account for these factors will reduce the factor of safety of the landing gear from that which it was certified with.

1 Due perhaps to very compliant landing gear, or a limitation to paved surfaces.


4

Figure 3: FU24 performing an uphill landing, note dirt flying up at point of impact.

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