flight test considerations - civil aviation safety · pdf fileflight test requirements...

MODs & STCsFLIGHT TEST CONSIDERATIONS

OBJECTIVE

Discuss Flight Test Aspects of Aircraft Modification and Supplemental Type Certification.

Types of Modification

STC Process

Flight Test Requirements

Flight Test Methods

OBJECTIVE

Modifications

Pods, FLIRs, Cameras etcCargo Pods

Sprayers and Water Bombers

Nose Booms, Wing Tip Mods and Tail StingersFloats and Skis

AntennaeAvionics and Cockpit Systems

Engines and Propellers

Flight Type ModificationsModifications with flight testing implications include:


Anything liable to affect handling or performance characteristics of the aircraft



Protrusion into the airflowEspecially;

- noticeable increase in drag index- altering wing lift characteristics (eg VGs) - in front of or near flight control surfaces- in front of or near static ports / pitot tubes



Changes to flight control systemControl surface size or travelTab gearing / spring size

Autopilots / SAS / Yaw Dampers



Engine and Power ChangesTurbo or superchargingPropellers



Engine and Power ChangesTurbo or superchargingPropellers

Also consider changes to noise signature.



Weight changesAny proposal to change CG limits


Any systems changes liable to affect operation of the aircraft



Cockpit ControlsEngine, Propeller, Fuel

CoolingInduction Icing

Landing Gear, Steering, Brakes



Flight InstrumentsElectricsAvionics / CommsSystems Integration / Autopilots



Cockpit EnvironmentVentilation

Field of ViewLightingSeating, HarnessesEntry and Exit



WorkloadIFR considerations


Any modification that requires changes to the Flight Manual for the aircraft


Any modification that requires changes to the Flight Manual for the aircraft

Or introduction of a Flight Manual Supplement

Supplemental Type Certificates

Supplemental Type CertificatesAircraft type certification is the process of the evaluation and approval of aircraft design data against designated design standards.Culminates in the issue of a Type Certificate (TC).A TC is a prerequisite for the issue of a Certificate of Airworthiness (CofA) for an individual aircraft.

Supplemental Type CertificatesAircraft type certification is the process of the evaluation and approval of aircraft design data against designated design standards.Culminates in the issue of a Type Certificate (TC)…....or a Supplemental Type Certificate (STC) …or a CAR 35 Design Approval.

Flight Test Process Three Phases:


Three Phases:

1. Applicant’s Developmental Test Flying


Flight Test Process

Three Phases:


2. Applicant’s Certification Test Flying to Demonstrate / Claim Compliance

Engineering Conformity!


Flight Test Process

Three Phases:


2. Applicant’s Certification Test Flying to Demonstrate / Claim Compliance

3. Authority’s Certification Test Flying to Validate Compliance




Flight Test Process


Experimental Certificates

•Detailed information contained in CASA AC 21.10(1) – Experimental Certificates

•Experimental Certificate only issued for specific purposes

•Research & Development

•Showing Compliance With Regulations



•Flight Test Areas

•Flight Test Program

•Flight Test Safety

•Test Planning

•Hazard Analysis / Risk Management

•Operating Conditions and Limitations




Test Pilot Qualifications•Information also contained in CASA AC 21.10(1) – Experimental Certificates

•Minimum requirements:

•Private Pilot’s Licence

•Appropriate Endorsements

•Or Written Permission under CAR 5.50(1)


Test Pilot Qualifications•Regulations do not require the nominated TP to hold specific test flying qualifications or experience!!!

•So who would make the grade?

•Review Applicant’s Test Plan

•Provide Advice

•Encourage Flight Test Risk Management

•Review Applicant’s Test Report

•Conduct a Flight Type Inspection

•(If Required)

•Review FMS


Flight Test Process – CASA Contribution

The Authority conducts flight tests only to verify compliance has been shown by the Applicant.

All experimental and developmentalflight testing, and flight testing to show/claim compliance, is the responsibility of the Applicant.





• VALIDATION

• SPOT-CHECKING

• REPEATABILITY

• Recommendation to the Delegate who then may, or may not, agree that compliance has been demonstrated.


Aircraft must continue to meet Certification Basis.

Aircraft must continue to meet Certification Basis.

All Airworthiness Standards, from the most complicated (eg FAR 25, FAR 29) to the simplest (eg BCAR-S), are presented in the same general layout♦:

♦Although specific paragraph numbers may be different.


Subpart A - GeneralSubpart B - FlightSubpart C - StructureSubpart D - Design and ConstructionSubpart E - PowerplantSubpart F - EquipmentSubpart G - Operating Limitations & InformationAppendices


Subpart A – GeneralApplicabilitySpecial Retroactive RequirementsAircraft Categories


Subpart B – FlightGeneral

Proof of Compliance (Testing Tolerances)Weight and Balance

PerformanceStall SpeedClimb and GlideTake-Off and Landing

Flight CharacteristicsControllability and ManoeuvrabilityTrim (…cont.)


Subpart B – FlightFlight Characteristics (Cont…)

StabilityStallsSpinning

Ground and Water HandlingMiscellaneous Flight Requirements

Vibration and BuffetHigh Speed Characteristics


Subpart C – StructureGeneralFlight LoadsControl Surface and System LoadsHorizontal Stabiliser and Balancing SurfacesVertical SurfacesAilerons and Special DevicesGround / Water / Emergency Landing LoadsFatigue


Subpart D – Design and ConstructionGeneral

Flutter

WingsControl SurfacesControl SystemsLanding GearFloats and HullsPersonnel Accommodation

(…cont.)


Subpart D – Design and Construction (Cont..)

PressurisationFire ProtectionElectrical Bonding and Lightning ProtectionMiscellaneous


Subpart E – PowerplantGeneralFuel SystemFuel System ComponentsOil SystemCoolingInduction SystemExhaust System

(…cont.)


Subpart E – Powerplant (Cont..)

Controls and AccessoriesFire Protection


Subpart F – EquipmentGeneralInstruments; InstallationElectrical Systems and EquipmentLightsSafety EquipmentMiscellaneous Equipment


Subpart G – Operating Limitations and InformationGeneralMarkings and PlacardsAirplane Flight Manual


Subpart A - GeneralSubpart B - FlightSubpart C - StructureSubpart D - Design and ConstructionSubpart E - PowerplantSubpart F - EquipmentSubpart G - Operating Limitations & InformationAppendices


Subpart A - GeneralSubpart B -Subpart C -Subpart D -Subpart E -Subpart F - EquipmentSubpart G - Operating Limitations & InformationAppendices

+ Hover / Low Speed / Climb Perf, - Stall / Spin

+ Rotors / Flight Controls,

- Wings, Empennage, etc

+ Rotor Drive Train

+ IFR Stability / Handling


Flight testing may not be required for all clauses…

…but each should be addressed in the Compliance Matrix.



Contentious ItemsPECsPerformanceSpinningFlutter - Vibes


Pressure Error CorrectionKeep mods as far away from static ports as possible……otherwise airspeed and altitude systems will need to be recalibrated……and operational speeds may need to be redefined.


PerformanceMay be scope to accurately measure the effect the mod has on one performance clause (eg OEI Climb)……and add conservative penalty in other cases……otherwise all clauses may be subject to flight testing.


SpinningSingle engine aircraft must continue to meet spin requirements of Clause 221.Flight testing may be required especially if…


SpinningMoments of Inertia change >5%.Power Available change >10%.Major Flight Control Mods.Incorporation of Canards.Major Wing Mods.Major Change to Airflow about Empennage.


Vibes - FlutterVibration and Buffet required if Mod sticks out into the airflow.Flutter?

Flight Test Methods

Philosophy:

•Certification Flight Testing should be conducted in accordance with the relevant Guidance Material.

•Or using agreed alternative methods of equal engineering rigour.

Flight Test Methods

References:

US FAA AC23-8B “Flight Test Guide for Certification of Part 23 Airplanes”.

US FAA AC25-7A “Flight Test Guide for Certification of Transport Category Airplanes”.

Flight Test Methods

US FAA AC27-1B “Certification of Normal Category Rotorcraft”.

US FAA AC29-2C “Certification of Transport Category Rotorcraft”.

References:

Flight Test Methods

Check also the FAA Advisory Circulars list. Includes ACson:

Engine ChangesWeight IncreasesSystems RequirementsIcing EquipmentRestricted Categoryetc…

References:

Flight Test Methods

PRINCIPAL CERTIFICATION FLIGHT TEST REFERENCES

The primary sources of information regarding procedures and flight test techniques for use during CASA certification flight testing are as follows:

•CASA Type Certification Procedures Manualhttp://www.casa.gov.au/manuals/regulate/type/index.htm

•CASA Advisory Circular 21.10(0) – Experimental Certificates -http://www.casa.gov.au/rules/1998casr/021/021c10.pdf

•CASA Advisory Circular 21.13(0) – Australian-Designed Aircraft – Certificationhttp://www.casa.gov.au/rules/1998casr/021/021c13.pdf

•CASA Advisory Circular 21.40(0) – Measurement of Airspeed in Light Aircraft – Certification Requirementshttp://www.casa.gov.au/rules/1998casr/021/021c40.pdf

•FAA Advisory Circular 23-8B – Flight Test Guide for Certification of Part 23 Airplanes.

•FAA Advisory Circular 25-7A – Flight Test Guide for Certification of Transport Category Airplanes.

•FAA Advisory Circular 27-1B – Certification of Normal Category Rotorcraft.

•FAA Advisory Circular 29-2C – Certification of Transport Category Rotorcraft.

•FAA Advisory Circular 90-89A – Amateur-Built and Ultralight Flight Testing Handbook

For links to FAA Advisory Circulars see the FAA’s Regulations and Policies page at:http://www.faa.gov/regulations_policies/

Flight Test Methods

Best Procedure for Mods Affecting Perf & Handling:

Flight Test Methods

Comparison


Flight Test Methods

Comparison

Before


Flight Test Methods

Comparison

And After


Flight Test Methods

Aircraft must still meet certification basis after any modifications likely to affect performance, handling or systems operation.

Flight testing may be required.

Must be done in accordance with References and with equal rigour as original certification flight tests.

Summary

CASA is here to help…please seek our advice.

Summary

flight test considerations - civil aviation safety · pdf fileflight test requirements...

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