RESEARCH REPORT Underwater Escape from Helicopters An Agency of the European Union Disclaimer This study has been carried out for the European Union Aviation Safety Agency by an external organization and expresses the opinion of the organization undertaking the study. It is provided for information purposes only and the views expressed in the study have not been adopted, endorsed or in any way approved by the European Union Aviation Safety Agency. Consequently it should not be relied upon as a statement, as any form of warranty, representation, undertaking, contractual, or other commitment binding in law upon the European Union Aviation Safety Agency. Ownership of all copyright and other intellectual property rights in this material including any documentation, data and technical information, remains vested to the European Union Aviation Safety Agency. All logo, copyrights, trademarks, and registered trademarks that may be contained within are the property of their respective owners. Reproduction of this study, in whole or in part, is permitted under the condition that the full body of this Disclaimer remains clearly and visibly affixed at all times with such reproduced part. No part of this report may be reproduced and/or disclosed, in any form or by any means without the prior written permission of the owner. REPORT NUMBER: Final report REPORT CLASSIFICATION: UNCLASSIFIED DATE: 11 November 2020 KNOWLEDGE AREA(S): DESCRIPTOR(S): Helicopter; evacuation; escape; underwater; survival; ditching; water-impact; exit; drowning; cold water; training. CUSTOMER: UK CAA CONTRACT NUMBER: EASA.2019.LVP.102 OWNER: European Union Aviation Safety Agency DISTRIBUTION: Public CLASSIFICATION OF TITLE: UNCLASSIFIED Author(s): Dr Susan Coleshaw Mr Dave Howson RESEARCH REPORT Underwater Escape from Helicopters CAA International Limited CAA International is the technical cooperation arm of the UK Civil Aviation Authority (UK CAA). 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Aviation House | Gatwick Airport South | West Sussex | RH6 0YR Crawley | United Kingdom | +44 (0) 330 0224401 | [email protected] | www.caainternational.com CONTENTS CONTENTS....................................................................................................................................... 5 SUMMARY....................................................................................................................................... 8 Problem area ................................................................................................................................... 8 Description of work .......................................................................................................................... 8 Results and application...................................................................................................................... 8 ABBREVIATIONS ............................................................................................................................... 9 GLOSSARY ......................................................................................................................................11 1. Introduction ............................................................................................................................13 1.1 Background .....................................................................................................................13 1.2 Overall Aims and Objectives ..............................................................................................14 1.3 Scope .............................................................................................................................14 2. Analysis of Information..............................................................................................................15 2.1 Literature........................................................................................................................15 2.2 Witness Evidence .............................................................................................................16 3. Literature Review .....................................................................................................................17 3.1 Review of Accident Reports ...............................................................................................17 3.1.1 General .................................................................................................................................................................. 17 3.1.2 Failure to escape................................................................................................................................................... 17 3.1.3 Seating, harnesses and crash attenuation.......................................................................................................... 18 3.1.4 Exit route used ...................................................................................................................................................... 18 3.1.5 Release of exits ..................................................................................................................................................... 19 3.1.6 Non-survivors recovered from the surface......................................................................................................... 20 3.1.7 Personal safety equipment problems ................................................................................................................. 21 3.1.8 Value of passenger briefings and training .......................................................................................................... 23 3.2 Review of Helicopter Underwater Escape Research...............................................................25 3.2.1 Brace position ....................................................................................................................................................... 25 3.2.2 Seating ................................................................................................................................................................... 27 3.2.3 Seat harness release............................................................................................................................................. 28 3.2.4 Size of underwater exits....................................................................................................................................... 30 3.2.5 Escape through underwater emergency exits.................................................................................................... 32 3.2.6 Disorientation ....................................................................................................................................................... 34 3.2.7 Vision underwater ................................................................................................................................................ 36 3.2.8 Cross-cabin escape ............................................................................................................................................... 37 3.2.9 Success and egress time....................................................................................................................................... 38 HUE - Final report PAGE 5 3.2.10 Full underwater escape trials.......................................................................................................................... 38 3.2.11 Effects of capsize angle.................................................................................................................................... 41 3.2.12 Cardiac responses to underwater escape ...................................................................................................... 42 3.2.13 Drowning during escape.................................................................................................................................. 44 3.2.14 Drowning following escape ............................................................................................................................. 45 3.2.15 Emergency breathing systems ........................................................................................................................ 46 3.2.16 Protection from cold........................................................................................................................................ 48 3.2.17 Occupant and test subject