OFFSHORE HELIDECK DESIGN GUIDELINES

Prepared by John Burt Associates Limited / BOMEL Limited

for the Health and Safety Executive

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PREFACE These offshore helideck design guidelines have been developed in response to an increasing awareness within the industry that offshore helideck operations can encounter problems that potentially affect flight safety. These problems may be caused by helideck layout and equipment deficiencies, structure-induced turbulence, hot gas plumes generated by turbines and flares or the effects of wind/wave-induced motions on helidecks on floating structures and vessels. Often the problems result in operating limits being imposed by the helicopter operators. Recommendation 10.3 (i) in CAA Paper 99004, a joint HSE / CAA sponsored report into offshore helideck environmental issues, was the main starting point for these guidelines along with an increasing number of non-conformities found during helideck inspections. HSE, with the support of the CAA and endorsement by the Offshore Industry Advisory Committees Helicopter Liaison Group (representing industry associations, trades unions and regulators), have commissioned the development of these guidelines. The objective is to provide designers and helicopter operators with the means to identify and understand the key issues that need to be addressed during design, fabrication and commissioning of helidecks. Good helideck design and operability also requires the designer and helicopter operator to have a clear understanding of regulatory requirements and the management and operational aspects of offshore helicopter logistics. These guidelines should therefore be read in conjunction with the latest editions of CAP 437 - Offshore Helicopter landing Areas - Guidance on Standards [Ref: 40] and the UK Offshore Operators Association Guidelines for the Management of Offshore Helideck Operations [Ref: 49]. They should be regarded as companion documents. The environmental research work, which is the foundation for Section 10 of these guidelines, was performed by BMT Fluid Mechanics Limited in conjunction with other specialists (e.g. DERA and JBAL). In addition, technical contributions from several experienced industry professionals and the findings from several other research projects form the substance of these guidelines. It is HSE's intention that these guidelines be periodically updated to reflect the outcome of ongoing industry research and advances in design and operating knowledge. Readers are therefore requested to send in their suggestions and comments for consideration to the HSE Hazardous Installation Directorate Offshore Division (Marine & Aviation Operations) at Rose Court, 2 Southwark Bridge, London, SE1 9HS and / or BOMEL Limited at Ledger House, Forest green Road, Fifield, Maidenhead, Berkshire, SL6 2NR.

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DISCLAIMER Whilst every effort has been made to ensure the data given in this document are both correct and up to date at the time of publication, the Health and Safety Executive and authors will not accept any liability for any erroneous, incorrect or incomplete information published in this document.

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ORGANISATIONS CONSULTED Association of British Certification Bodies (ABCB) British Helicopter Advisory Board (BHAB) British Rig Owners Association (BROA) Civil Aviation Authority (CAA) Cogent / Offshore Petroleum Industry Training Organisation (OPITO) International Association of Drilling Contractors (IADC) International Association of Geophysical Contractors (IAGC) International Association of Oil & Gas Producers (OGP) International Marine Contractors Association (IMCA) Inter Union Offshore Operations Committee (IUOOC) Maritime & Coastguard Agency (MCA) Offshore Contractors Association (OCA) United Kingdom Offshore Operators Association (UKOOA)

PROJECT MANAGEMENT BOMEL Limited

TECHNICAL SPECIALIST & EDITOR John Burt Associates Limited

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CONTENTS

PREFACE III

DISCLAIMER IV

CONTENTS VII

1.0 INTRODUCTION 1 1.1 Purpose 2 1.2 Scope 2

2.0 THE OFFSHORE HELICOPTER OPERATING ENVIRONMENT 5 2.1 Introduction 5 2.2 The Offshore Platform Operator / Vessel Owners Perspective 5 2.3 The Offshore Helicopter Pilots Operating Environment 6 2.4 Helideck Problems Encountered on the UKCS 7

3.0 THE OFFSHORE HELIDECK DESIGN PROCESS 11 3.1 Introduction 11 3.2 Design 11

4.0 REGULATIONS, DESIGN CODES & VERIFICATION 17 4.1 Introduction 17 4.2 Regulations 18 4.2.1 Aeronautical Legislation and Enforcement 18 4.2.2 Offshore Helidecks Legislation & Enforcement 19 4.3 Selecting Appropriate Design Codes 21 4.3.1 Fixed Installations 21 4.3.2 Mobile Installations and Vessels 21 4.4 Verification 22 4.4.1 Introduction 22 4.4.2 Safety-Critical Elements 22 4.4.3 Performance Standards 23 4.4.4 The Process 23 4.4.5 Helideck Design Appraisal 24 4.4.6 Providing Information for Operating and Flight Crew Operations Manuals 25 4.4.7 Limited Helideck Operations 26

5.0 DESIGN SAFETY CASES 27 5.1 Introduction 27 5.2 Risk and Operability Assessments 28 5.3 Helideck Assessment Strategy 29

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5.4 Performance Assessment And Review 30 5.5 Template for a Design and Operability Report 30

6.0 HELIDECK AND FACILITIES LAYOUT 37 6.1 Introduction 37 6.2 Developing a Helideck Design Specification 37 6.2.1 General 37 6.2.2 Reference Publications and Guidance 37 6.3 Installation / Vessel Layout Considerations 38 6.3.1 Main References 38 6.3.2 General 38 6.3.3 Helideck Physical Characteristics 40 6.3.4 Helideck Orientation 41 6.3.5 Assessing Suitability of the Proposed Helideck Arrangement 42 6.4 The Safe Landing Area 48 6.4.1 Main References 48 6.4.2 General 48 6.5 Helicopter Parking Facilities 50 6.5.1 Introduction 50 6.5.2 Main References 51 6.5.3 Design Considerations 51 6.5.4 Hangars 53 6.6 Obstacle Free Environment 54 6.6.1 Main References 54 6.6.2 Obstruction Clearances 54 6.6.3 Limited Obstacle Sector 54 6.6.4 Falling Gradient 55 6.7 Control, Access And Escape 55 6.7.1 Main References 55 6.7.2 Helideck Control Room 55 6.7.3 Access and Escape Routes 56

7.0 FLOATING STRUCTURES AND VESSELS 57 7.1 Introduction 57 7.2 Mobile Drilling Rigs 58 7.2.1 Introduction 58 7.2.2 Main References 58 7.2.3 Specific Features to Consider in MODU Helideck Design 58 7.3 Floating Production Systems 67 7.3.1 Introduction 67 7.3.2 Main References 67 7.3.3 Specific Features to Consider in FPSO Helideck Design 68 7.3.4 Marine Operating Environment 69

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7.3.5 Vessel / Helideck Classification / Verification Process 70 7.3.6 Optimising Helideck Location and Layout 71 7.3.7 Shuttle Tanker Operations 71 7.4 Specialist Vessels 72 7.4.1 Introduction 72 7.4.2 Main References 73 7.4.3 Specific Features to Consider in Vessel Helideck Design 73 7.5 Motion Considerations And Operating Limits 76

8.0 OTHER INSTALLATION ARRANGEMENTS 77 8.1 Combined Operations 77 8.1.1 Introduction 77 8.1.2 Main References 79 8.1.3 Design Considerations 79 8.1.4 Safety Cases 81 8.1.5 Management of Combined Operations Helidecks 82 8.2 Normally Unattended Installations 83 8.2.1 Introduction 83 8.2.2 Main References 84 8.2.3 Definitions 84 8.2.4 Seeking the Safest and Most Efficient Helideck Design Options for

Operations to NUIs 85 8.2.5 Equipment Design Considerations 85

9.0 HELIDECK STRUCTURES 91 9.1 Introduction 91 9.2 Main References 92 9.3 Landing Surface 93 9.3.1 Wood 93 9.3.2 Steel 93 9.3.3 Aluminium 93 9.4 Support Structure 95 9.4.1 Introduction 95 9.4.2 Materials 95 9.4.3 Design 96 9.4.4 Interconnected Modules 96 9.4.5 Maintenance 97 9.5 Appurtenances 97 9.6 Load Combinations and Load Factors 97 9.6.1 Introduction 97 9.6.2 Emergency landing 98 9.6.3 Normal Operations and Helicopters at Rest 99 9.6.4 Design Loadings 99

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9.7 Helideck Friction Surface and Landing Nets 101 9.7.1 Friction Surface 101 9.7.2 Main References 101 9.7.3 Design Considerations 101 9.7.4 Helideck Landing Nets 102 9.7.5 Helideck Net Fixings 103 9.7.6 Helideck Landing Net Removal 106 9.8 Access and Escape 107 9.8.1 Introduction 107 9.8.2 Main References 107 9.8.3 Access General Considerations 108 9.8.4 Escape - General Considerations 109 9.8.5 Platforms 109 9.8.6 Walkways 111 9.8.7 Stairways and Ladders 111 9.8.8 Control of Personnel Access to Helideck 112 9.9 Drainage 112 9.9.1 Introduction 112 9.9.2 Main References 112 9.9.3 Environmental Considerations 113 9.9.4 Operational Considerations 113 9.9.5 Design Considerations 113 9.10 Perimeter Safety Net 115 9.10.1 Introduction 115 9.10.2 Main References 115 9.10.3 Design Considerations 115 9.10.4 Areas to be protected by Perimeter Safety Net 116 9.10.5 Combined Handrail and Safety Nets for Vessels 116 9.10.6 Construction and Inspection Considerations 117 9.10.7 Perimeter Safety Net Load Testing 121 9.11 Tiedown Arrangements 121 9.11.1 Introduction 121 9.11.2 Main References 121 9.11.3 Design Considerations 121 9.12 Helideck Surface Trip Hazards 124 9.13 Helideck Structural Maintenance 124 9.13.1 Main References 124 9.13.2 Introduction 124

10.0 HELIDECK ENVIRONMENTAL EFFECTS 127 10.1 Introduction 127 10.2 Main References 127 10.3 Background 127

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10.4 Design Issues 129 10.4.1 Introduction 129 10.4.2 Aerodynamic Issues and Criteria 130 10.4.3 Plan Location of the Helideck 131 10.4.4 Helideck Height and Air Gap under the Helideck 132 10.4.5 Proximity to Tall Structures 134 10.4.6 Temperature Rise due to Hot Exhausts 136 10.4.7 Cold Flaring and Rapid Blow-down Systems 139 10.5 Special Considerations for Floating Systems and Vessels 140 10.5.1 General 140 10.5.2 Wave Motion Characteristics and Criteria 141 10.5.3 Sea State Characterisation 142 10.5.4 Vessel Motions and Helideck Downtime 142 10.5.5 Helideck Location Dependence 142 10.6 Special Considerations for FPSOs and Dynamically Positioned Vessels 145 10.7 Combined Operations 146 10.7.1 Permanent Arrangements 146 10.7.2 Temporary Arrangements 147 10.8 Examples of Good and Bad Practice in Platform Helideck Location 148 10.8.1 Fixed Installations 149 10.8.2 Semi-submersible and jack-up drilling units 150 10.8.3 Tension Leg Platforms 152 10.8.4 FPSOs 153 10.9 Methods of Design Assessment 155 10.9.1 Introduction 155 10.9.2 Wind Flow Assessment 155 10.9.3 Wind Climate 161 10.9.4 Prevailing Wind Direction 163 10.9.5 Upwind Helideck Location 164 10.9.6 Estimating Helideck Downtime Due to Wind 167 10.10 Presentation of Wind Flow Assessment Results 169 10.10.1 General 169 10.10.2 Presentation of Flow Assessment Results for Design 169 10.10.3 Presentation of Flow Assessment Results for Operations 176 10.11 Wave Motion Assessment 179 10.11.1 Wave Induced Motion Estimates 179 10.12 Wave Climate 180 10.12.1 Limiting Motion Criteria 180 10.13 Estimating Helideck Downtime Due to Waves 182

11. HELIDECK SYSTEMS 183 11.1 Introduction 183 11.1.1 Hazardous Area Classification and Equipment Selection 183

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11.2 Visual Aids - Markings 184 11.2.1 Introduction 184 11.2.2 Main References 184 11.2.3 Helideck Markings 184 11.2.4 Installation / Helideck Identification 185 11.2.5 Obstruction Markings 187 11.3 Visual Aids - Lighting Systems 188 11.3.1 Main References 188 11.3.2 Considering the Offshore Lighting Environment 189 11.3.3 Specific Requirements for NUIs 191 11.3.4 Perimeter Lighting 192 11.3.5 Floodlighting 195 11.3.6 General Lighting 198 11.3.7 Obstruction Lighting 199 11.3.8 Windsock Lighting 202 11.3.9 Status Lights 204 11.4 Electrical Power Supplies 207 11.4.1 General Philosophy 207 11.4.2 Design Considerations 208 11.5 Fire Protection Systems 208 11.5.1 General 208 11.5.2 Main References 209 11.5.3 Firefighting Safety Goals and Objectives 209 11.5.4 Requirements of a Foam System 211 11.5.5 Design Criteria for Foam Systems 211 11.5.6 Design Considerations for Monitor Systems 212 11.5.7 Water / Foam Systems 217 11.5.8 Hydrant Systems and Equipment 218 11.5.9 Complementary Media 221 11.5.10 Helideck Fire Detection 223 11.6 Rescue Equipment Provisions 224 11.6.1 Main References 224 11.6.2 Rescue Equipment Cabinets 224 11.6.3 Rescue Equipment Inventory 227 11.7 Helicopter Refuelling 228 11.7.1 Introduction 228 11.7.2 Main References 228 11.7.3 Operational Considerations 228 11.7.4 General Design Considerations 229 11.8 Communications Equipment 235 11.8.1 Introduction 235 11.8.2 Main References 235

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11.8.3. Location of Equipment and Aerials 236 11.8.4 Aeronautical VHF Radio 237 11.8.5 Marine VHF Radio 238 11.8.6 Helideck Crew Portable VHF Sets 238 11.8.7 NDB Equipment 238 11.8.8 Public Address and Alarm Systems 239 11.8.9 Video Briefing System 240 11.9 Meteorological Equipment 240 11.9.1 Introduction 240 11.9.2 Main References 241 11.9.3 Equipment Requirements 241 11.9.4 Wind Velocity and Direction Measuring Equipment 242 11.9.5 Air Temperature Measuring Equipment 245 11.9.6 Barometric Pressure Measuring Equipment 246 11.9.7 Visibility Measuring Equipment 247 11.9.8 Cloudbase Measuring Equipment 248 11.9.9 Vessel Motion Measuring Equipment 248 11.9.10 Automatic Meteorological Instrument Station 249 11.10 Miscellaneous Helideck Equipment 250 11.10.1 General 250 11.10.2 Helicopter and Helideck Washdown and Cleaning Equipment 251 11.11 Bird Control Devices 251 11.12 Safety Signs and Posters 254 11.12.1 Introduction 254 11.12.2 Main References 254 11.12.3 Specifying Safety Signs 254 11.12.4 General Helideck Signs 255 11.12.5 Heli-Admin Signs and Posters 256

APPENDIX 1 - CONTRIBUTORS 260

APPENDIX 2 - REFERENCES 262

APPENDIX 3 - LIST OF ABBREVIATIONS 269

APPENDIX 4 BELL 214ST - DESIGN INFORMATION 273

APPENDIX 5 EH INDUSTRIES EH101 - DESIGN INFORMATION 275

APPENDIX 6 EUROCOPTER EC155 - DESIGN INFORMATION 277

APPENDIX 7 EC225 - DESIGN INFORMATION 279

APPENDIX 8 EUROCOPTER AS332L1 - DESIGN INFORMATION 281

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APPENDIX 9 EUROCOPTER AS332L2 - DESIGN INFORMATION 283

APPENDIX 10 EUROCOPTER AS365N2 - DESIGN INFORMATION 285

APPENDIX 11 SIKORSKY S61N - DESIGN INFORMATION 287

APPENDIX 12 SIKORSKY S76 - DESIGN INFORMATION 289

APPENDIX 13 SIKORSKY S92 - DESIGN INFORMATION 291

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1.0 INTRODUCTION These guidelines have been developed and published under the sponsorship of the Health & Safety Executive supported by the Civil Aviation Authority and endorsed by the Offshore Industry Advisory Committee Helicopter Liaison Group (OIAC-HLG) to provide technical information about the design and operation of helidecks and their facilities and to indicate current good practice. The OIAC-HLG membership is comprised of HSE, CAA, BHAB, UKOOA, BROA, IADC, IMCA and the trades unions TGWU and AMICUS (MSF). Since oil and gas exploration activities began on the United Kingdom Continental Shelf (UKCS), the Offshore Industry has been dependent on the efficient and safe use of helicopters for logistics and emergency support. The primary role is moving people to and from their workplaces on the offshore facilities. Other roles include freight movement, emergency evacuation and search and rescue. Over the thirty years or so since oil and gas activities commenced on the UKCS, helicopter travel has become the norm for the workforce. A measure of the scale of this vital activity since the early sixties is that there have been in the order of 6 million flights and 45 million passenger movements within the UKCS (1968 2002). The introduction of helicopters in the early sixties as a routine offshore workhorse has increasingly brought the associated operational support activities into sharper focus. The harsh operating environment, some serious and fatal accidents and the emergence of goal setting regulations offshore have all contributed to a greater awareness of the problems associated with operating helicopters in a marine environment. However, this greater awareness of operating problems has not always been matched by a full and clear understanding of requirements at the interfaces between aviation, oil and gas production and processing and marine operations. Helideck surveys carried out between 1992 and 1995 by the Civil Aviation Authority (CAA), on behalf of the Health & Safety Executive (HSE) [Ref: 34] revealed deficiencies concerning the physical layout of helidecks, helideck operations, maintenance, standards of equipment and the competence and training of helideck crews that were subsequently corrected. It is vital that the technical requirements for helicopter operations are properly identified during the conceptual design of an installation and given full consideration at all subsequent stages from detailed design through to fabrication,

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construction, installation and commissioning, operations and any subsequent modification. Technologically, helicopters have improved significantly during the period they have operated on the UKCS. Aircraft designers, maintenance engineers, flight crews, Helicopter Operators and the Regulators continue to seek improvements to helicopter safety and reliability. Offshore Installation Owners and Operators, and vessel owners should similarly recognise the need to continuously improve the standards of helideck hardware and their operating management of helicopter facilities.

1.1 PURPOSE These guidelines are intended to: Assist those involved with the conceptual and detailed design of helideck

systems to specify the equipment on offshore installations, MODUs and vessels, in order to provide suitable helideck arrangements that will ensure good availability under both normal and emergency operating conditions

Assist onshore and offshore personnel responsible for the management of

offshore helicopter and helideck operations to provide safe and efficient offshore helicopter services

Provide Independent Competent Persons (ICPs) who are undertaking

verification of offshore helideck and facilities design and operations inspections and audits with examples of good industry practice.

1.2 SCOPE The guidelines are intended to comprehensively address the routine and key technical issues that are known to arise in the design and construction of offshore helidecks and the execution of UKCS offshore and helideck operations. In so doing, the guidelines should provide industry with advice and technical information on good helideck design and construction practices and the acceptable operating standards that duty holders and vessel owners are reasonably expected

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to adopt. Duty Holders should be careful to use up to date editions of the reference documents mentioned herein. It is acknowledged that advances in technologies used in helideck design will continue as a result of ongoing research and development projects and will have occurred during the preparation of these guidelines. Therefore, under the sponsorship of OIAC-HLG, the content of this document will be reviewed and periodically updated to embody the latest information.

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2.0 THE OFFSHORE HELICOPTER OPERATING ENVIRONMENT

2.1 INTRODUCTION The offshore helicopter operating environment is viewed quite differently by the various organisations and people that are involved in the wide range of activities, from helideck design through to actual offshore helideck operations. The various parties include: Installation Operators / Vessel Owners Management (Duty Holders) Helicopter Operators (AOC Holder), Flight Crews and Maintenance

organisations Helicopter Landing Officers (HLOs), Deck Crews and Service Providers Helideck Designers, Fabricators and Technical Support Specialists

(Consultants) Installation / Vessel Project Engineering & Construction Management Regulators. Several individuals and organisations will be involved in the lifetime management of a helideck design and its routine operation. It is the different perspectives held by these individuals and organisations that can, and often does, lead to inadequate helideck facilities and support arrangements being provided, particularly when they act or operate in isolation from one another. The following sections serve to offer an insight into the end users perspectives and thus provide a better understanding of the overriding operational requirements and outcomes that should be given priority consideration.

2.2 THE OFFSHORE PLATFORM OPERATOR / VESSEL OWNERS PERSPECTIVE The helicopter crew, HLO and deck crews are the end users. They have to endure the day-to-day problems in operations caused by any errors and omissions during initial helideck specification, design and construction. The installation operator, MODU or vessel owner makes the capital expenditure (CAPEX) for the design and construction of a helideck. They also pay the operating expense (OPEX) during life of field helicopter operations.

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Reductions in capital expenditure by economising on helideck design and construction costs may well prove very expensive in operating costs. Therefore, their primary objective should be to ensure that for a given CAPEX, the helideck and its systems give value for money over the life of the facility. This means ensuring that the helideck and systems design will provide for safe and efficient flight operations. Design deficiencies that increase OPEX should be avoided. The helideck and facilities designers (usually several discipline engineers) are tasked with developing the helideck structure and systems design for fabrication and construction. Simply following oil field tradition and practice during the design phase will invariably embody all the errors and omissions that have accumulated in helideck designs over the years. An integrated and well-informed approach by operations and project management and the discipline engineers is more likely to produce a good operational helideck and support systems.

2.3 THE OFFSHORE HELICOPTER PILOTS OPERATING ENVIRONMENT Offshore flight operations are a highly complex and specialised process. It requires high levels of training, competence and skill to plan a flight, land and take-off from an offshore installation and to consistently execute the task safely and efficiently under normal, good weather flying conditions. When a task is carried out in adverse weather (e.g. poor visibility), during night flying and when other predictable and / or unpredictable factors routinely found in and around the environs of an offshore installation or vessel are encountered, the skills of flight crews can be stretched. Unlike pilots operating from onshore airfields, offshore helicopter crews have relatively little ground-based technology and fairly limited information to assist them as they commence their final approach for a landing on an offshore helideck. It is much the same when taking-off. Despite the many advances in aircraft technology, navigation, landing and communications aids in recent years, there are currently no reliable and effective

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electronic landing aids available for use on offshore installations / vessels. Therefore, offshore helicopter crews have to rely heavily on their acquired skills and experience when approaching, landing and taking-off from offshore installations / vessels. It is not necessary or appropriate to review the whole scope of helicopter flying in these guidelines. However, it is to essential to consider two important topics concerning flight crew activities that are performed within the offshore flight operations process. These are: 1. pilot information, and 2. approach, landing and take off manoeuvres. Helideck Designers are recommended to acquaint themselves with these topics. They are covered in detail in the UKOOA Guidelines for the Management of Offshore Helideck Operations [Ref: 49].

2.4 HELIDECK PROBLEMS ENCOUNTERED ON THE UKCS In recent years, HSE and CAA have jointly funded a number of studies and research projects that have included analysis of incidents and other statistical data relating to offshore helicopter safety. CAA Paper 99004 [Ref: 41] provides two good measures of the extent of problems encountered by offshore helicopters due to adverse helideck environmental conditions. In 1997, a count of the BHAB Helidecks Installation / Vessel Limitations List (IVLL) now renamed the Helideck Limitations List (HLL) showed the following:

UNRESTRICTED HELIDECKS RESTRICTED HELIDECKS

96 (25.6%) 279 (74.4%)

Restrictions referred to in the IVLL included notified non-compliances (e.g. physical obstructions in 210 sector and 5:1 infringements) and limitations / comments arising from flight experience (e.g. turbulent sectors and turbine exhaust effects). It is important to note that the restricted helidecks are not confined only to older Installations, MODUs and vessels (e.g. those built over 20 years ago or more). Restrictions continue to be established and imposed by the Helicopter Operators

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Helideck Technical Committee for basic deficiencies on helidecks that have been more recently installed. In the same CAA Paper, an analysis of 18 accident reports (see following table) taken from the CAA SI&DD, Mandatory Occurrence Reporting (MOR) database shows that defects in Installation design can be cited as the cause for two thirds of the occurrences. This situation clearly suggests that helideck operability was not properly addressed during the initial design phase of the Installations concerned. Such design deficiencies can seriously undermine operational efficiency and compromise safety

FLIGHT PHASE AT OFFSHORE INSTALLATION

APPROACH LANDING TAKE-OFF HOVER CLIMB

5 (27.8%) 9 (50.0%) 2 (11.1%) 2 (11.1%) 0 (0%)

PRIMARY CAUSE

FLARE / BURNERS TURBULENCE EXHAUST PLUMES PILOT ERROR

4 (22.2%) 7 (38.9%) 3 (16.7%) 4 (22.2%)

SECONDARY CAUSE

FLARE / BURNERS

TURBULENCE EXHAUST PLUMES

PILOT ERROR OTHER

0 (0%) 9 (50%) 2 (11.1%) 3 (33.3%) 4 (22.2%)

FAILURE CATEGORY

INSTALLATION DESIGN AIRCRAFT OPERATION

12 (66.7%) 6 (33.3%)

Further evidence to demonstrate the need for ensuring that design and operation of helidecks on the UKCS are properly managed, is illustrated in the following table. The table takes data from the CAA SI&DD, Mandatory Occurrence Reporting (MOR) database over the period 1975 to 2001 and provides a breakdown of non-fatal reportable accident causes.

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In recent years, as a result of several flight safety initiatives, a significant reduction in the number of non-fatal reportable accidents on the helicopter side of the equation is noted. The number of non-fatal reportable accidents caused by installation / vessel deficiencies remain fairly constant, in line with flight activity levels.

NUMBER OF OCCURRENCES

CAUSE 1975-1983 1984-1992 1993-2001

Aircraft Related Incidents

(e.g. Flight Crew, Operations, Weather, Manufacture, Maintenance, etc.)

15 19 5

Installation / Vessel Related Incidents

(e.g. Helideck Operations, Adverse Helideck Environment, Vessel Motions,

etc.)

2 6 2

In addition to fatal and non-fatal reportable accidents the MOR Database also records other occurrences.

These relatively minor occurrences take place in greater numbers but are equally as important from an offshore flight safety viewpoint. They require appropriate actions to be taken to prevent recurrence. From an aviation perspective the occurrences are typified by events such as engine and other component failures and operational shortcomings. Their effects are generally contained within the design and operating capability of helicopters. Other occurrences are helideck environmental issues, offshore helideck management and operational procedure violations. Avoiding these violations is part of the substance for these guidelines.

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3.0 THE OFFSHORE HELIDECK DESIGN PROCESS

3.1 INTRODUCTION The purpose of this part of the guidance document is to identify the topics and expand the requirements that need to be properly considered in the design and fabrication of new helidecks and the modification of existing helidecks, regardless of the type of facility to which they are fitted.

3.2 DESIGN Offshore helideck and facilities design can be broken down into a sequence of events within an overall project process. The process is illustrated in the following figures: Figure 3.1 Defining the Basic Requirements for a Helideck Figure 3.2 Verification / Classification Process and Selecting Design Codes Figure 3.3 Facility and Helideck Layout Considerations Figure 3.4 Specifying the Helideck and Support Systems.

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Figure 3.1 - Defining the Basic Requirements for a Helideck

What is the Project Logistics

intent ?

Is a helicopter landing area

required? If yes,

W hat is the Project Design

Helicopter ?

What type of offshore installation / vessel / helicopter operations

are envisioned?

Mobile ?(e.g. FPSO,

MODU, Vessel)

Fixed ? (e.g. manne d or

un - manned)

Is helicopterrefuelling required ?

Under what jurisdiction is the

facility to operate ?

What is the predicted marine operating

environment ?

Is a parking / laydown area

required ?

What is the predicted meteorological operating

environment ?

See F igure 1 . 2

If yes, determine the operational

fuel usage and fuel storage capacity

required, including reserves

Decide verification / classification process and establish project

design codes

See Figure 1.3

See F igure 1 . 4

See Fig. 3.2

See Fig. 3.3

See Fig. 3.4

Fixed? (e.g. Manned or NUI)

What is the Project Logistics

intent ?

Is a helicopter landing area

required? If yes,

W hat is the Project Design

Helicopter ?

What type of offshore installation / vessel / helicopter operations

are envisioned?

Mobile ?(e.g. FPSO,

MODU, Vessel)

Fixed ? (e.g. manne d or

un - manned)

Is helicopterrefuelling required ?

Under what jurisdiction is the

facility to operate ?

What is the predicted marine operating

environment ?

Is a parking / laydown area

required ?

What is the predicted meteorological operating

environment ?

See F igure 1 . 2

If yes, determine the operational

fuel usage and fuel storage capacity

required, including reserves

Decide verification / classification process and establish project

design codes

See Figure 1.3

See F igure 1 . 4

See Fig. 3.2

See Fig. 3.3

See Fig. 3.4

Fixed? (e.g. Manned or NUI)

Figure 3.1 - Defining the Basic Requirements for a Helideck

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Figure 3.2 - Verification / Classification Process and Selecting Design Codes Figure 3.2 - Verification / Classification Process and Selecting Design Codes

Authority Jurisdictions for the operating location correctly

identified and advised to project?

All applicable regulations identified, advised to project

and complied with

All applicable project helideck design codes (structures &

systems) and operating procedures identified and

advised to project

Fixed Installations

(incl. FPSOs)

Mobile Installations

(incl. MODUs)

Specialist Vessels

(DSVs, etc.)

Classification Society / Verification Authorities

identified and appointed, where appropriate

ICAO Annex 14 Vol 2CAP 437

IMO MODU code SOLAS (Ships)

Flag State Rules Ships Rules (Class)Industry Guidelines

(Also if designated an offshore installation)

Flag State (Marine) Regulatory

Requirements

Offshore Health & Safety

Regulatory Requirements

Aviation Regulatory

Requirements

(Also if designated an Offshore Installation)

Figure 3.2 - Verification / Classification Process and Selecting Design Codes

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Figure 3.3 - Facility and Helideck Layout Considerations

YES

Project design helicopter

established

Determine maximum safe landing area

required

Determine available helideck locations on the installation

Assess all potential adverse helicopter

environmental effects

Can the full obstruction free environment be obtained without incurring operating limitations?

Can the dead and imposed loads of the helideck and support

structure be accommodated?

Can adverse environmental factors be minimised and

helideck operability assured?

Have all the appropriate regulatory and code requirements been

complied with?

Has the extent and operating impact of any potential flight limitations been properly considered and passed as

acceptable by the helicopter operator or by an aviation specialist?

NO

Reappraise design layout and find

solutions

FIX helideck design

layout

YES

Determine maximum required helideck

size and shape

Figure 3.3 - Facility and Helideck Layout Considerations

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Figure 3.4 - Specifying the Helideck and Support Systems

(Section Numbers refer to these guidelines)

Safe Landing Area (SLA) and overall

helideck location, size and shape determined

(Sections 6 & 10)

Structural support design / material

/construction requirements identified

and satisfied (See Section 9)

Helideck design, material, surface, access & escape

selected (Sections 6 & 9)

Refuelling system

required? (Section 11.7)

Fire Protection

systems requirements identified and

capacities calculated(Section 11.5)

Lighting systems requirements specified &

adequate electrical power (main & UPS)

available (Sections 11.3)

Communications and meteorological

equipment requirements identified and properly

specified (Sections 11.8 & 11.9)

Alarm & public

address systems identified & specified

(Section 11.8)

Helideck motion

recording system and equipment identified &

specified (FPSOs, MODUs & Vessels)

(Section 11.9)

Aviation Fuel storage and

supply systems identified, located

and sized (Section 11.7)

Helideck, identification, installation side signage and obstruction markings

properly specified (Sections 11.2)

All visual aids (markings

and lighting) properly identified and set out

(Sections 11.2 & 11.3)

Fire protection & rescue

equipment properly specified

(Sections 11.5 & 11.6)

Aviation fuel system and equipment

properly specified(Section 11.7)

Protective clothing

requirements identified and specified

(Section11.6.4)

All miscellaneous helideck

equipment, safety equipment and signs, etc.

properly identified and specified

(Sections 11.10 & 11.12)

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4.0 REGULATIONS, DESIGN CODES & VERIFICATION

4.1 INTRODUCTION There are a significant number of regulations governing the use of helicopters and the provision of facilities for their operation on the UKCS. These Guidelines identify the regulations in force at the time of publication, but users of this document should always ensure that they refer to the latest issue of any regulation; particularly new or revised HSE Publications and HSE and CAA research and development papers (See Appendix 2). Over the years several documents have been published in the form of legal requirements, official notices, guidance and good industry practice for offshore helicopter operations. The essential elements of these documents will be found referenced in the text and appendices of these Offshore Helideck Design Guidelines. This section deals with the legislation and enforcement with respect to helideck design, construction and verification as two distinct subjects: aeronautical operations, and offshore helideck operations.

The offshore regulations do not apply to vessels that are not designated as Offshore Installations, UK or Flag State Marine Law applies to these vessels. Aeronautical operations regulations and guidelines make no such distinction on the UKCS: Aviation Rules always apply. It is, however, recommended that owners and builders of vessels with helidecks that will operate on the UKCS, in support of oil and gas operations, seriously consider the advantages of complying fully with the UK offshore and aviation regulatory requirements. There is considerable operational and commercial benefit to be obtained by employing the most rigorous design standards. This design guide is written with these standards in mind.

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4.2 REGULATIONS

4.2.1 Aeronautical Legislation and Enforcement As these Guidelines deal only with offshore helideck operations, it is not intended to detail the legislation and enforcement regime as it applies directly to the maintenance and operation of helicopters. Helicopter Operators are obliged to comply with relevant Aviation Law. The onus is on the Helicopter Operators, as holders of Air Operators Certificates (AOC) to ensure that any landing site meets minimum requirements. If a helicopter operator finds serious failings and deficiencies in the facilities, he may decide not to authorise the helideck for use. The primary instrument of civil aviation legislation in the UK is the Civil Aviation Act 1982 [Ref: 2]. Under the 1982 Act, CAA is responsible for operation of the Air Navigation Order (ANO). The legislation is supported by Civil Aviation Publications (CAPs). CAP 437 [Ref: 40] is the primary UK aviation standard for the design of offshore helidecks. This standard contains the criteria that an AOC Holder will use in order to authorise the helideck for use by Flight Crews. Offshore helidecks fall within the definition of unlicensed aerodromes and are outside the CAA licensing remit. However, the CAA will provide advice on any items of non-compliance with the helideck physical characteristics and emergency equipment requirements according to the guidance provided in CAP 437. Acting on behalf of the offshore helicopter operators, BHAB Helidecks assess and inspect helideck designs and apply appropriate operational restrictions where there are non-compliances. The CAA monitors the operational restrictions that are imposed by BHAB Helidecks through its regulation of the helicopter operators. It is therefore important to realise that non-compliance with design criteria of CAP 437 may result in significant loss of helicopter operational flexibility (e.g. reduction in available payloads or even a landing ban in certain weather conditions). Frequently found non-conformities during BHAB Helideck inspections are highlighted in the appropriate sections of these guidelines.

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4.2.2 Offshore Helidecks Legislation & Enforcement This section addresses the regulatory requirements and enforcement affecting Offshore Installation operators, mobile offshore drilling unit (MODU) owners and, where appropriate, vessel owners. The responsibility for regulating and enforcing the health, safety and welfare of employees offshore rests with the HSE Offshore Division (OSD).

4.2.2.1 Health and Safety at Work Act The Health and Safety at Work, etc. Act 1974 (HASAWA) [Ref: 1] is the principal legislation safeguarding the health, safety and welfare of workers in the UK offshore oil and gas industry. The Act applies to places and activities specified in the Health and Safety at Work etc. Act 1974 (Application Outside Great Britain) Order 1995 (SI 1995/263) [Ref: 4]. This includes helideck activities on offshore installations, but not helicopters while in flight. Flag State laws and ICAO and IMO conventions may also apply to shipping activities (e.g. specialist vessels). MODUs may be both Installations and ships and, therefore, have to comply with both regimes. The Offshore Installations and Wells (Design and Construction, etc.) Regulations 1996 (SI 1996/913) (DCR) [Ref: 8] place responsibility for ensuring the safe design and construction of offshore installation landing areas on the installation duty holder. This generally means the operators of fixed installations and owners of mobile installations, floating production units and some vessels.

4.2.2.2 Offshore Legislation The Offshore Installations (Safety Case) Regulations 1992 (Sl 1992/2885) (SCR) [Ref: 5] require Operators and Owners to submit a Safety Case (See Appendix 2) which demonstrates that they have an adequate safety management system, have identified major accident hazards, assessed the risks from those hazards, and taken the measures necessary to reduce the risks to persons to as low as reasonably practicable (ALARP).

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In addition, the following regulations have relevance to offshore helicopter operations: The Offshore Installations and Pipeline Works (Management and

Administration) Regulations 1995 (SI 1995/738) (MAR) [Ref: 6] The Offshore Installations (Prevention of Fire and Explosion, and

Emergency Response) Regulations 1995 (SI 1995/743) (PFEER) [Ref: 7]

The Offshore Installations and Wells (Design and Construction, etc.)

Regulations 1996 (SI 1996/913) (DCR) [Ref: 8]. Designers should be aware that the above regulations may subsequently be modified by other enabling legislation which introduces new or amended requirements that may have an affect on the intent of the original regulations.

Approved Codes of Practice (ACOP) that provide interpretation of these Regulations, along with other non-mandatory guidance are listed in Appendix 2. Duty holders who comply with ACOPs are deemed to comply with the pertinent regulations. The supporting guidance to DCR, Regulation 11 (Helicopter Landing Area) refers to the relevant CAA published guidance, CAP 437 [Ref: 40]. Duty Holders of Offshore Installations and owners of vessels having a helideck should always ensure that compliance with CAP 437 is established initially (subject to any declared non-compliance), and subsequently maintained. The CAA is in a position to enforce certain standards on helicopter operators. Essentially, this means that a helideck shall meet the minimum standards set out in CAP 437. Where these standards cannot be achieved in full, BHAB Helidecks apply relevant restrictions. The HSE regards CAP 437 as appropriate guidance regarding helideck standards. In extreme cases where CAP 437 criteria cannot be fully met, this could entail a landing ban on the installation, MODU or vessel in certain weather conditions and / or on night operations.

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4.3 SELECTING APPROPRIATE DESIGN CODES The selection of appropriate design codes at the commencement of design is essential to ensure that the helideck structure and support systems are fit for purpose and meet UK regulatory and operational requirements.

4.3.1 Fixed Installations

Generally, selection of appropriate regulations, guidance and design codes for design and construction of a fixed installation to be placed on the UKCS is a straightforward matter. These guidelines address many of the current requirements throughout the text and should therefore provide designers with a good appreciation of the standards to be adopted.

4.3.2 Mobile Installations and Vessels The selection of appropriate regulations, guidance and design codes for MODU and vessel helidecks is a different and often more complex matter. Essentially, the starting point is the Owners specification for the MODU or vessel and this will dictate such things as the Country / Port of Registration, vessel class, operating regions, Classification Society, etc. If the MODU or vessel helideck is to be used operationally on the UKCS there are potentially a number of conflicts likely to arise between UK and International requirements and Classification Society Rules, particularly where the MODU or vessel is designed and constructed outside the UK. It is therefore the responsibility of the MODU or vessel owner to address and resolve all possible regulatory and code conflicts when writing the initial vessel specification if the helideck is intended to operate in UK waters without having severe operating restrictions imposed by BHAB Helidecks. Design areas where conflicts in the requirements generally occur are:

Helideck structural codes and passive fire protection (particularly if

aluminium helideck structures are specified) Helideck size, allowable mass and obstruction criteria Helideck and installation / vessel markings Lighting systems

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Firefighting system selection, capacities and coverage Rescue equipment scales. The above areas where potential MODU and vessel design and construction requirements may conflict are covered in more detail in Section 7.

4.4 VERIFICATION

4.4.1 Introduction The Offshore Installations and Wells (Design and Construction, etc.) Regulations 1996 (SI 1996/913) (DCR) have amended the Offshore Installations (Safety Case) Regulations 1992 (SI 1992/2885) (SCR) to replace the Certification regime established by the, now revoked, Offshore Installations (Construction and Survey) Regulations 1974. The Safety Case centred Regulations dispensed with the concept of a Certifying Authority and place sole responsibility for the development and ongoing maintenance of a safe Installation onto the Operator or Owner (Duty Holder). It is recommended that vessel owners operating in UK waters adopt a similar approach to that described below where they have an operational helideck installed. There is close correlation between the fundamental requirements of classification and that of verification. There is also the basic requirement to comply with CAP 437. For legal and practical reasons, therefore, it makes good sense to apply this design guidance to all helidecks.

4.4.2 Safety-Critical Elements Operators / Owners are required to list the Safety-Critical Elements (SCEs), have them subject to independent review and develop a scheme for verification of their performance throughout the life cycle of the installation. UKOOA Guidelines for the Management of Safety-Critical Elements [Ref: 51] provide further detailed information. An Offshore Installation helideck is a collection of systems, some of which are safety-critical or have safety-critical sub-systems or components. This means that a failure in any part of its operation could cause, or substantially contribute to, a major accident at the installation with potentially serious consequences for installation, helicopters and workforce.

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Sub-systems contributing to safety-criticality may include: Helideck Power Helicopter firefighting Drainage Escapeways Emergency Lighting This list of items arises from the helideck function as a means for evacuating the installation / vessel in an emergency (where possible under certain defined scenarios). Also, failure of helideck safety systems (e.g. firefighting system) may prevent the on-board capability from limiting the effects of a helicopter accident on the helideck.

4.4.3 Performance Standards

Performance standards should be set by the Installation Operator, MODU or vessel owner to measure or assess the suitability and effectiveness of the helideck and to assure and verify that the helideck structure, systems and equipment are fit for purpose. Meeting the installation integrity requirements of DCR and PFEER performance standards also contribute to assuring the SCEs for the helideck. In setting the performance standards to comply with offshore legislation, it should also be recognised that the requirements of CAP 437 must be met in order to obtain BHAB Helidecks clearance for routine flight operations. Therefore, CAP 437 should be used as the basis for setting the relevant SCE performance standards. SCE performance standards do not cover the auditing of helideck operational aspects. These should be covered in the installation Safety Management System (SMS). However, they are equally important.

4.4.4 The Process Having set the performance standards, independent and competent persons should be selected by the operator / owner to prepare, or be consulted on the verification scheme and to implement it. It is for the operator / owner to decide how this is to be achieved. The prime requirement of the verifying body is an adequate capability to assess the importance of defects. Independent in this context may include employees of the installation operator, MODU or vessel owner, provided they have not been involved technically in the design and planning of the relevant parts of the installation and that their management lines should be separate from those whose work they are checking.

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It is also important to ensure that the objectivity of those undertaking verification works is not compromised. The scope and level of the verification scheme should define what parameters will be measured; equipment tested or designs reviewed. It should also define how these measurements will be undertaken. When, where and how often the performance standards will be measured or assessed during the life cycle should be specified. There should also be a system for verifying that the performance standards have been achieved. The personnel carrying out routine inspection and testing and the personnel who will independently verify this work may cover this.

4.4.5 Helideck Design Appraisal During development of a new helideck or the modification of an existing helideck, independent and competent person(s) should conduct a design appraisal and fabrication survey to verify that the helideck and its systems meet the specified performance standards (see CAP 437) and is fit for purpose in respect of the following items, as a minimum: size and structural adequacy for selected helicopter orientation to prevailing winds gas / exhaust emissions and turbulence environment effects of vessel motions (if applicable) suitable helideck height clear landing approach and take-off paths obstructions within permitted limits falling gradient (i.e. 5:1) access and escape routes parking arrangements, if provided lighting markings friction surface tiedowns helideck net and perimeter safety net refuelling facilities firefighting equipment hardware aspects helideck details in the Operations Manual.

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During the helideck design verification process, the appropriate design documents including drawings, wind tunnel test reports, etc. should be reviewed and verified by an independent competent person (ICP). BHAB Helidecks should also be notified at the commencement of new helideck designs or modifications to existing helidecks and, when appropriate, consulted on issues concerning potential non-compliances with CAP 437 requirements. At the conclusion of the helideck design and fabrication, a set of up to date design documents including drawings, wind tunnel test reports, etc. should be passed to BHAB Helidecks for their review, comment and retention. It should be clearly understood that modifications on installations, MODUs and vessels in areas off the actual helideck and some distance away can adversely affect helideck operations (e.g. the addition of new modules, repositioning of gas turbine exhausts and vent systems, etc.). Upon satisfactory completion of the helideck Hook Up and Commissioning, BHAB Helidecks should be notified in order for them to undertake an initial inspection of the helideck and its systems prior to the commencement of flight operations. The inspection will follow the approved Offshore Helideck Inspection Report (OHIR) format. This initial inspection, along with an appraisal of the relevant design documents, will highlight non-compliances and thus assist BHAB Helidecks with determining whether operational limitations should be applied.

4.4.6 Providing Information for Operating and Flight Crew Operations Manuals One of the imperatives at the conclusion of helideck design and construction is to provide relevant and complete technical information for future use by the helideck and flight crews. As part of the inspection / acceptance process BHAB Helidecks require a full set of plans and documentation as listed on the Offshore Helideck Inspection Report (OHIR). Information to be gathered for inclusion in the installation or vessel operations manuals should be largely the same as that required to develop the Design and Operability Report (template provided in Section 5.5). In particular, it is essential to include any information to be provided in written instructions to flight crews, OIMs and helideck crews.

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Vendor information, data sheets, operating instructions and maintenance and test manuals should also be obtained for each piece of procured equipment and provided for use on the facility.

4.4.7 Limited Helideck Operations

In the event that helideck operations are likely to be restricted as a result of design or construction deficiencies, the problems likely to be encountered and the likely costs incurred by the duty holder during operations should be clearly understood and justified to the helideck owner by the designers.

Installation operators, MODU and vessel owners should instruct Topsides and Helideck Design Contractors to advise them formally of any helideck or associated system deficiencies arising from the overall installation, MODU or vessel helideck designs that may give rise to helicopter or helideck operational restrictions and / or additional operating expense.

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5.0 DESIGN SAFETY CASES

5.1 INTRODUCTION The Offshore Installations (Safety Case) Regulations 1992 (SCR) (SI 1992/2885), among other things require installation owners and duty holders to identify all hazards which could cause a major accident, including helicopter accidents, and to take measures to reduce the risks to as low as is reasonably practicable (Regulation 8). The approach taken when making these Regulations was to set objectives. The objectives were then expanded further in guidance on the regulations. However, it is noted that, with respect to helicopter operations, the guidance on Safety Case Regulations is focused mainly on the hazards and risks to an installation and its personnel from impacts by aircraft. It does not specifically encompass the hazards and risks to a helicopter and its passengers from the installation and its processes. Duty Holders, including Designers, should adequately address the potential effects on helicopter flight operations caused by adverse operating environments created on and around offshore installations. These adverse effects may result from production and power generation processes and structures on the installation or from adjacent installations and vessels. When combined with local weather conditions the resultant effects can place helicopters in jeopardy, particularly during critical flight phases. Duty Holders including Designers should, in particular, assess any hazards due to hydrocarbon gas release, exhaust emissions, physical turbulence generation and lit flares. Failure modes of installation, MODU or vessel systems that have the potential to affect the safety of helicopters should also be assessed (e.g. loss of heading control on a vessel whilst a helicopter is located on the helideck). References to these studies should be made in the Design and Operations Safety Cases. HSE has recognised the need to consider the hazards to helicopters created by an installation, MODU or vessel. The joint HSE / CAA research project resulting in CAA Paper 99004 [Ref: 41] concluded (Conclusion No: 29) that guidance in the past has been solely and erroneously concentrated on the risk to the installation and has not explicitly encompassed the hazards the installation may pose to the helicopter. HSE Safety Notice 4/99 [Ref: 23] draws duty holders attention to the need to consider installation or vessel induced hazards for helicopters.

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5.2 RISK AND OPERABILITY ASSESSMENTS There are a number of situations where the actions of the duty holder could be prejudicial to the safety of helicopter operations. These include: 1. Poorly controlled activities which could adversely affect the wind flow over

the helideck, such as design modifications to the topside layout or blocking air gaps under the helideck (where these are provided) thereby reducing the effectiveness of the design air gap.

2. Combined operations (e.g. involving closely positioned workover rigs or

flotels) where the effects of windflow, exhausts and proximity on helicopter operations have not been considered. There may be conflict between flights to adjacent installations, however, bridge linked units can make a choice of helideck available.

3. Lack of awareness on the part of the OIM of the impact of routine platform

activities on helicopter operations can also be important. Gas turbine exhaust plumes are largely invisible to a helicopter pilot but can be detrimental to helicopter handling and performance. Information on the operational status of such equipment should be made available to pilots.

4. Releases of hydrocarbon gas, whether due to an unforeseen accident, or

as part of a controlled blowdown of process equipment, also represent a hazard to helicopters. Where a condition can exist which may be hazardous to the helicopter or the occupants, duty holders should install helideck status lights.

5. Diesel exhaust emissions can also cause serious degradation to the

quality of the flying environment. This is particularly so in respect of the fumes and airborne particulates associated with diesel exhausts. The thermal effects from diesel exhaust emissions on helicopter rotor, engine control and performance are generally less than from gas turbine exhausts operating at higher temperatures.

The sample strategy, outlined in Section 5.3, is provided to maximise coverage of the helideck assessment.

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5.3 HELIDECK ASSESSMENT STRATEGY When preparing risk and operability assessments the duty holder should particularly address the following issues by preparing a schedule of key factors likely to have an impact on the safety of helicopter operations. The schedule should include, but is not necessarily limited to: The maintenance of unobstructed air flow over and under the helideck Consideration of the likely impact on the airflow situation due to changes

in the topside layout that could range for example from temporary storage under the helideck to more permanent changes such as the addition of cladding to the drilling derrick

The operation of gas turbine units in situations where hot exhaust gasses

may be emitted into the path of a helicopter

Flaring and blowdown of flammable gas which may be prejudicial to helicopter operations

The location, operation and maintenance of wind recording equipment

Combined operations involving another installation or vessel in the vicinity

of the installation with potential to disturb the airflow significantly or to emit hot exhaust into the flight path of a helicopter

The Safety Management System for an installation should set the

standards and monitor compliance against a set of established operational requirements designed to minimise environmental hazards to helicopter operations

Standards to be attained and procedures to be used for monitoring the

control of installation activities to ensure an acceptable level of safety for helicopter operations is maintained

Ensuring procedures are in place for communicating relevant information

to helicopter operators in a timely manner, including any departure from agreed operational practice, which may have an adverse effect on helicopter safety.

Offshore safety requires co-operation between everyone who has a contribution to make to ensure health and safety on an offshore installation or the activities

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involving the installation. The scope of Regulation 8 of MAR is, therefore, very wide and includes operators, owners, concession owners, employers, employees, managers and people in charge of visiting vessels or aircraft.

5.4 PERFORMANCE ASSESSMENT AND REVIEW When reviewing the assessments, helideck design and operability and the intended arrangements for helicopter operations should be assessed against current guidelines and good industry practice. The overall scope of individual duty holder submissions will vary considerably, and the guidance given in this document may assist with assessing the completeness of the case for safety. It is also important for the duty holder to have a good measure of the operability of a helideck and facilities design in terms of the proposed operating arrangements and the predicted operational performance (e.g. availability). A performance assessment can be made using the template set out in Section 5.5.

5.5 TEMPLATE FOR A DESIGN AND OPERABILITY REPORT

5.5.1 Report Objectives The objectives of a Design and Operability Report are:

1. To present an overview of the facilities design and the provisions being made for supporting helicopter operations to and from an installation or vessel.

2. To provide relevant information about the helideck and support systems

design and operability, to enable the verification process to be completed. 3. To achieve acceptance for flight operations by the helicopter operators

(BHAB Helidecks) with minimum operating limitations. 4. To provide a document that interfaces with the Safety Case and provides

relevant operating information for helicopter crews and helideck teams.

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5.5.2 Suggested Report Structure Section 1 Introduction Preferably limited to general statements about the facility and to report objectives. Section 2 Management Summary To include statements on the completion of design and operability assessment activities, completion of helideck hook-up and commissioning activities and overall conclusions on the helideck operational status and acceptability. Section 3 Documentation Provide listings of key helideck project and vendor design drawings, design specifications, data sheets and reports (e.g. helideck wind tunnel testing). The information that is provided for each document should include the Document number, Originator, Title, Revision and Approval status and date. Section 4 Logistics & Operations Philosophy Following a brief introduction, the contents of this section should address the installation, MODU or vessel operator's preferred or specific aircraft selection, routings and payload expectations. Diversion and adverse weather polices should be included along with relevant information on intended search & rescue provisions / coverage and a statement on adverse weather policy. The field operators requirements (taken from initial design specification) for the helideck and facilities should be noted along with any variations requested as design proceeds. Additionally, the installation / vessel operators requirements for helicopter refuelling, passenger and freight handling should be noted. Finally, a brief statement covering the installation / vessel operators existing facilities and operating experience should be included.

Section 5 Regulatory Requirements and Verification Process This section should briefly set out the regulations, rules, codes and standards that are applicable to the helideck design, fabrication, construction and verification processes. It is also prudent to identify each of the official bodies concerned with the verification of the helideck, its support facilities and their areas of involvement. This process is usually simple for UK fixed installations but, in the case of FPSOs, MODUs and vessels, which may retain class for world-wide operations, it can be more complicated. It is therefore essential to identify the classification aspects,

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which introduce the need to observe international conventions that may conflict with established UK offshore requirements. Verification meetings and the initial BHAB Helidecks review and inspection should be noted. Reference to the outcomes and outstanding work lists should be included. Section 6 Design and Operability Review This section should address the whole range of topics relevant to the helideck design and its future safe operation. Sub-sections should cover the following: 1. Production and Operating Environments Includes field / operating location(s), environmental conditions, the facility layout and leading particulars, production processes and helideck / helicopter transportation risk assessments. 2. Aircraft Operating and Performance Considerations Data relevant to helicopter types that may use the helideck, For example, motion limits imposed on FPSOs, MODUs and vessels. 3. Helicopter Landing Area Operational Standards Information provided should include the landing area height (vessels should include variations to draught conditions AMSL), wind direction, frequency and velocity distribution, vessel motions affecting helicopter operations including a motion analysis (when applicable).

4. Helicopter Landing Area Physical Characteristics This section should address the following list of topics and should clearly demonstrate that each element has been properly considered during the design phase. It is essential that any reduction or infringement of the dimensional or obstruction clearance requirements set out in CAP 437 is highlighted and full justification given for the anticipated operating limitations. Similarly where the requirements are exceeded these should also be stated. Helicopter Safe Landing Area size Overall helideck size (if larger than the basic safe landing area) 210 Obstacle Free Sector

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0.12 D Limited Obstacle Sector (0.62 'D' from centre of D circle) 0.21 D Limited Obstacle Sector (0.83 'D' from centre of D circle) 5:1 Falling Gradient The adverse effects of combined operations on clearances (if applicable) Helideck and landing area design, materials, airgap, etc. Helideck friction surface / helideck net Helicopter tiedown points arrangement, fittings, etc. Perimeter Safety Net Access and Escape arrangements Routine or emergency parking and laydown arrangements (drawings to be

provided showing locations and revised obstruction clearances) Helideck drainage.

5. Aerodynamic and Process Thermal Effects on the Helideck and

Helicopters This is a key section that deals with providing good information for flight crews on the likely adverse flying effects (aircraft handling difficulties and pilot workload) they may encounter from turbulence over the helideck and around the installation / vessel environs during approach, landing and take-off. Potential turbulence (from structures, etc.) and thermal sources (from gas turbines, diesel exhausts, process vents and flares, etc) that are identified during model testing (using physical or CFD methods) should be quantified and fully explained. Estimates of helideck operability should be provided and conclusions drawn in respect of flight safety and the potential for additional operating costs if accepting helideck operational impairment and landing limitations [Ref: 68].

6. Visual Aids It should be demonstrated that helideck and obstruction markings fully meet CAP 437 requirements. Any deviation must be justified and accepted by a competent agency. This section should also address helideck and other associated lighting systems, their power sources and control. The lighting systems will include perimeter and surface lights, floodlights, general helideck and installation / vessel lighting, status lights, etc. Information should be provided on system design, equipment selection and lighting performance. Finally, statements should be made to demonstrate that the design and location of installation / vessel identification markings / signs have been properly addressed in

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order to eliminate the potential for wrong deck landings. Reference should be made to CAP 437 (side signage) and HSE Operations Notices 14 and 39 [Refs: 24 & 26]. 7. Firefighting and Rescue Facilities This section should summarise the detection, protection and firefighting philosophy adopted for the helideck landing area (e.g. the identification and control of helideck emergencies) and its support systems (e.g. helifuel storage and supply). As a minimum, it should be clearly demonstrated that the systems design, equipment selection, operation and maintainability meet relevant offshore regulations and the requirements of CAP 437. Details of rescue equipment, helideck crew protective equipment and breathing apparatus should be included. 8. Helicopter Fuelling Facilities Where helicopter fuelling facilities are provided, the following topics should be addressed: basic system requirements storage requirements bulk capacity and location fuel supply and dispenser systems design and locations.

9. Helicopter Operations Support Equipment This section should summarise the many items of helicopter operations support equipment. Items will include, but not necessarily be limited to: Meteorological equipment Communications equipment Helicopter starting unit Safety and information signs and posters Aircraft tiedown equipment Aircraft chocks Windsocks Passengers, baggage & freight weighing equipment Helideck de-icing equipment Safety briefing system.

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Section 7 Matters to be Provided for in Written Instructions This section should include references and information specific to the helideck and its systems that should be embodied in the installation, MODU or vessel Operations Manual and Emergency Procedures. Also, where there is a need for notifications to helicopter operators, specific operating procedures or maintenance instructions to be written, these should be included. Details should also be included about Flight Information Reporting including meteorological reporting and vessel movement. A HORG or Route Guide plate will be generated for the installation, MODU or vessel based on information provided to BHAB Helidecks. This document is a summary of the key points about an installation landing site and is made available to flight crews. Ideally, a draft Plate should be prepared (with appropriate graphics and text) to include all the information that will be required in the formally published document. Ideally, the information should be accompanied by a three-dimensional digital image. Examples of route guides are given in UKOOA Guidelines for the Management of Offshore Helidecks [Ref: 49]. APPENDICES Appendices should be used where considered appropriate to assist document readability. As a minimum, an A3 sized general arrangement drawing should be included clearly illustrating the installation / vessel plan and an elevation (showing the helideck arrangements), details of the helideck and its helicopter operating criteria and equipment layout.

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6.0 HELIDECK AND FACILITIES LAYOUT

6.1 INTRODUCTION The purpose of this section is to identify the topics that should be considered in the design and fabrication of new helidecks and in the modification of existing helidecks. It also identifies experience-based practical requirements for the operation and maintenance of a helideck, regardless of the type of facility to which it is fitted.

6.2 DEVELOPING A HELIDECK DESIGN SPECIFICATION

6.2.1 General At the conceptual stage of an installation, MODU or vessel design, a firm commitment is required from the owner or operator to ensure that a good operating environment is obtained for safe and efficient helicopter operations. A positive management commitment at this stage should ensure that, at each stage in the design process, proper consideration is made for the future helicopter operations, alongside other competing priorities. The ideal helideck design can rarely be achieved due to an offshore installation, MODU or vessel's other activities and priorities (e.g. process, drilling, power generation, and diving operations), the working environment including vessel motions in the case of floating installations and vessels. Inevitably, the outcome will always be a compromise with the other activities. However, the designer should make every effort to ensure that the helideck is truly Fit for Purpose.

6.2.2 Reference Publications and Guidance It should be noted there are only a few authoritative publications that provide general guidance for helideck designs e.g. the International Civil Aviation Organisation (ICAO) codes, CAA Standards, Mobile Offshore Drilling Units (MODU) codes, etc. These codes have been identified in Section 4.3 and in Appendix 2. It is therefore important to give careful consideration to the topics in the following sections. They are not in order of priority, nor exhaustive.

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6.3 INSTALLATION / VESSEL LAYOUT CONSIDERATIONS

6.3.1 Main References CAP 437, Chapter 2 is the starting point for helideck and facilities design in the UKCS.

6.3.2 General The helideck is a vital support system for all offshore operations. Failure during design to maximise helideck operability may have far reaching implications during operations. These implications are typified by flight restrictions (sometimes severe), and have the potential for increased operating expense that may later lead to costly modifications. It s important that the design of the helideck is regarded as a key component of the structure, allowing for the safe transportation of personnel and equipment, as well as a primary escape route in an emergency. The design therefore needs to be integrated and not regarded as an appendage to the main structure. On fixed installations and some floating structures, helidecks are generally placed on top of an accommodation module. Vessels tend to vary quite a lot with bow helidecks either mounted above bridge level or above the foredeck, positioned aft and elevated above the main deck or accommodation block level and, in some cases, offset outboard. Layouts are invariably established following the basic published landing area dimensional minima (i.e. CAP 437). It is recommended the designer also give careful thought and attention to operational criteria. It is therefore essential whilst developing a specification and obtaining approval for construction to: 1. Clearly define the purpose and characteristics of the installation, MODU or

vessel on which the helideck will be installed. 2. Identify the operating intentions of the installation operator, MODU or

vessel owner. Maintain flexibility of design as far as practicable, to cater for future changes of use. Identify all key features of the installation, MODU or vessel that may significantly affect helideck design.

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For example a consensus decision is made to operate helicopters only by daylight (e.g. on a NUI) and therefore a decision is made not to install any helideck lighting. The CAA might point out that, since this is a design decision, they will not permit any emergency evacuation flights at night and the HSE will therefore need to see a Safety Case which does not involve helicopters for night use of any kind, routine or emergency.

3. Identify and eliminate, or reduce as far as possible, the hazards

associated with helideck operations. These hazards may include, but are not necessarily limited to, the following:

Excessive windflow turbulence due to adjacent structures or

process thermal effects (e.g. turbine exhausts, normal and emergency hydrocarbon cold venting systems), which may cause helicopter handling problems

Obstructions in the approach or departure sectors

Emergencies such as helicopter crashes, fires or fuel spills requiring

a rapid response and therefore unimpeded helideck access

The potential for personnel contact with main or tail rotors whilst on deck

The potential for loose items of equipment being sucked into rotors

or air intakes by structure induced turbulent airflow or rotor downwash

Consider provision of protected stations for helideck crews to avoid

danger from possible crash debris or rotor plane movement after landing.

4. Consult competent aviation specialists, the aviation or logistics staff of the

Owner or Operator, the CAA, BHAB Helidecks and helicopter operators as necessary.

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6.3.3 Helideck Physical Characteristics The helideck structure should be designed to accommodate a safe landing area (D circle) suitable for the largest and heaviest helicopter that it is anticipated will use the helideck. The operator or owners project and logistics staff should provide this information. This information is fundamental in any helideck design and will enable designers to determine the minimum overall size of the helideck and safe landing area and the required load bearing strength of the structure. The Safe Landing Area (SLA) is the actual area on a helideck enclosed and delineated by the Perimeter Line marking. D is the imaginary circle described on drawings to establish the SLA dimensions and clearances for a selected helicopter (See CAP 437). The operational needs of the installation, MODU or vessel and the helicopter crews, helideck crews and passengers should also be taken fully into account. To do this, it is prudent for the designer to explore potential opportunities for enlarging the shape of the helideck beyond the minimum safe landing area requirement. This obviously needs to be done whilst keeping in mind the ultimate weight, size, structural loadings and economics of the final structure. When selecting and fixing the final helideck size, shape and configuration, the following factors should be properly considered and mitigated: The safe landing area (SLA) should be positioned for optimum operational

efficiency and clearance from obstructions (See Section 6.4). Also, the SLA should be positioned toward an appropriate outboard edge of the main structure so that overflying installation structures is avoided, and there are adequate clear landing and take-off sectors available

Safe passenger access to and egress from a helicopter in both normal

and emergency situations in all weather conditions

Safely performing routine helideck crew activities such as refuelling, freight and baggage handling, fire fighting and rescue, and maintenance requirements

The need to provide a parking area for an unserviceable helicopter to

make the landing area available for a recovery aircraft should be seriously considered. This facility may be operationally desirable where alternate landing sites / arrangements cannot be easily obtained.

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Doing this exercise properly will help to determine the overall helideck dimensions that are required, over and above the safe landing area.

Simple examples for developing helideck configurations are given in Section 6.6 and a selection of actual helideck arrangements is illustrated in the following plates. The actual helideck arrangements shown are not necessarily optimum helideck designs without any operating restrictions. Figure 6.4 Fixed platform (NUI) with cantilevered helideck Figure 6.5 Accommodation vessel with helideck above buoyancy legs and

anchor winches (also note the provision of 2 helidecks) Figure 6.6 FPSO with aft mounted helideck Figure 6.7 Drilling / Production ship with bow mounted Helideck (above bridge) Figure 6.8 Seismic vessel with foredeck mounted helideck Figure 6.9 Seismic vessel with aft mounted helideck Figure 6.10 Mobile Offshore Drilling Unit (MODU) with helideck Inboard of the

buoyancy legs and anchor winches Figure 6.11 Jack-up drilling rig with cantilevered helideck.

6.3.4 Helideck Orientation

6.3.4.1 Fixed Installations

The jacket, topsides, and riser strength and fatigue considerations for the chosen location of the facility will primarily dictate the orientation of fixed installations. Potential hydrodynamic and wind loadings on the structure have to be taken into account during design for the predicted oceanographic and environmental conditions likely to be encountered offshore. Reference should be made to Section 10 where this topic is discussed in detail with respect to helideck environmental effects.

6.3.4.2 FPSOs and Vessels

Ship-shaped FPSOs and Vessels generally have the ability to move their heading into the weather and, as a result, they have greater operational flexibility when optimising helideck orientation and movement for the prevailing winds. This feature is addressed in more detail in Section 7.

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6.3.4.3 MODUs, Jack-Ups and other Semi-Submersibles MODUs and Jack-ups, when operating alone, are effectively the same as fixed installations when determining the helideck orientation. For example, in the Northern North Sea, the preferred orientation for a MODU is about 300 True because this is where the most severe weather comes from (e.g. winds and waves). When MODUs, Jack-ups and other Semi-Submersibles (e.g. Floatels) are positioned for combined operations there is a need to integrate several key marine (e.g. anchoring) and operating (bridging, etc.) requirements. The marine, drilling and other operational positioning considerations will take priority.

This tends to cause some loss of flexibility for orienting the helideck to optimise wind flows. However, in this mode of operation there will usually be a choice of operational helideck. This situation is addressed in more detail in Section 7.

6.3.5 Assessing Suitability of the Proposed Helideck Arrangement 6.3.5.1 Introduction

Having decided upon the initial layout and before proceeding further with detailed design, the designer should examine operational effectiveness of the proposed arrangements with respect to both physical (space and other material aspects) and with respect to potential environmental effects.

6.3.5.2 New Designs and Modifications to Existing Installations The following sections of these design guidelines address in detail operational considerations, helideck systems and support equipment. The designer may draw on this information for new installations in order to achieve a detailed design that follows good industry practice based on practical considerations that are supported by field experience. For existing installations that are being modified, a review may be necessary to assess the effects of any new plant and equipment on the operability of the helideck. Examples of modifications that could affect operability include the construction of an additional accommodation or other module and provision of satellite dish nearby.

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6.3.5.3 Helideck Environmental Considerations Section 10 of these design guidelines deals with assessing the potential effects on helicopters from aerodynamic and thermal environments and wave motions that may be encountered around offshore helidecks.

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(Photograph courtesy of John Burt Associates Limited)

Figure 6.1 Fixed platform (NUI) with cantilevered helideck

(Photograph courtesy of Shell Exploration & Production)

Figure 6.2 Accommodation vessel with helideck above buoyancy legs and anchor winches (note the provision of two helidecks and large hangar facility between)

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(Photograph courtesy of Conoco UK Ltd)

Figure 6.3 FPSO with aft mounted helideck

(Photograph courtesy of Amerada Hess Limited)

Figure 6.4 Well test / production vessel with bow mounted helideck (above bridge)

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(Photograph courtesy of Western Geco)

Figure 6.5 Seismic vessel with foredeck mounted helideck

(Photograph courtesy of Western Geco)

Figure 6.6 Seismic vessel with aft mounted helideck (note: the streamers are deployed and

the helideck perimeter safety net is raised to act as handrailing with the handrailing in raised position the helideck is inoperative)

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(Photograph courtesy of Dolphin A/S)

Figure 6.7 Mobile offshore drilling unit (MODU) with helideck inboard of the buoyancy legs and anchor winches (Note: this is a poor arrangement due to the significant 5:1 infringement,

which will incur operating restrictions).

(Photograph courtesy of Maersk)

Figure 6.8 Jack-up drilling rig with cantilevered helideck

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6.4 THE SAFE LANDING AREA

6.4.1 Main References CAP 437, Chapter 2.

6.4.2 General The safe landing area (SLA) must be big enough to accommodate the largest helicopter that the landing area is intended to serve. The SLA is the area of a helideck that is contained within the WHITE Perimeter Line. This does not necessarily mean that the SLA will be the largest possible D circle that can be accommodated within the overall structural dimensions of a helideck. Examples of helidecks with various Safe Landing Area arrangements are shown in the following figures 6.10 to 6.12 (see also previous sections that address the need to optimise helideck layout). The SLA should be given full and proper consideration from an operational perspective whilst laying out the helideck arrangement during the conceptual design phase of an installation or vessel. D is the largest dimension of the helicopter when the rotors are turning and in a conventional helicopter with an exposed tail rotor; it is the distance from the front of the main rotor tip path to the rear of the tail rotor tip path. The parameter D (overall length) for the chosen helicopter is found in CAP 437 D Value and Helicopter Type Criteria along with the aircraft weight data. Importantly, the SLA should be carefully positioned on the helideck to give an obstruction free environment (see Section 4.7 for details), which will provide adequate landing, overshoot and take-off paths, ample clearance from structures, etc. during helicopter manoeuvres and sufficient space for the helideck crew to operate and passengers to embark and disembark safely.

Where the overall size of the helideck structure can be made larger than the SLA the designer is strongly recommended to take full advantage of any extra space that is available to maximise separation of the SLA from any adjacent structures and possibly to create a run-off (parking) area.

Helideck enlargement is particularly important on vessels with forward mounted helidecks where any additional space gained to create more forward visual cues for landing is a highly desirable feature. Where helideck space is limited and the windflow is over the bow, the helicopter will land on the helideck with its tail rotor towards the Limited Obstacle Sector (e.g.

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vessel superstructure) and the flight crew will be unable to see the helideck surface in front of the nose of the helicopter. Therefore, with more space behind the helicopter and thus, the provision of greater separation, there is less likelihood for an inadvertent tail rotor strike. This topic is covered in more detail in Section 7.

Figure 6.9 Example of a coincident safe landing area and D circle extending to the boundary of the helideck structure. Note: 'H' offset 0.1D towards outboard edge.

Figure 6.10 Example of a safe landing area extending to the boundary of the whole helideck structure. Note D circl