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Research Initiatives for Improving the Safety of Offshore Helicopter Operations. David Howson UK Civil Aviation Authority. Background. 1982 - Helicopter Airworthiness Review Panel (HARP) - 1984 - Helicopter Human Factors Working Group - 1984 - Helicopter Health Monitoring Working Group
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Research Initiatives for Improving the Safety of Offshore Helicopter Operations David Howson UK Civil Aviation Authority
Background • 1982 - Helicopter Airworthiness Review Panel (HARP) - 1984 - Helicopter Human Factors Working Group - 1984 - Helicopter Health Monitoring Working Group • 1986 - Chinook fatal accident • 1987 - Helicopter Safety Research Management Committee (HSRMC) • 1992 - Cormorant ‘A’ fatal accident - 1993 - Review of Offshore Safety and Survival (RHOSS) • 2003 – European Aviation Safety Agency (EASA)
Helicopter Health Monitoring Research • In-service trials to evaluate suitability of technology for the environment very successful. • Voluntary retrofit of HUMS funded by oil companies. • Seeded defect test programmes to investigate effectiveness. • Advanced analysis of HUMS VHM data: - objective to enhance analysis using unsupervised machine learning. - interim results very promising - sensitivity significantly improved and false alarm rate reduced!! - implementation will be ground station software update.
Helicopter Emergency Flotation Research – Ditching Stability • Mismatch between certification standards and wave climate in North Sea - high capsize rate. • Mismatch between time needed to escape and breath-hold time. • Float scoops provide one sea state stability improvement at low cost. • Mitigate consequences of capsize via provision of fall-back ‘side-floating’ attitude. • Hydrodynamic and egress aspects successfully tested.
Helicopter Emergency Flotation Research – Water Impact • Largest cause of fatalities in survivable water impacts is drowning. • Best way of enhancing safety is to improve post crash operability of EFS. • Finite element and empirical modeling to establish impact loads for range of water impacts. • Automatic arming and deployment. • Provision of redundant flotation unit(s), e.g. float(s) needed for ‘side-floating.
Helideck Environmental Research • Environmental hazards: - turbulence, - windshear, - turbine exhausts, - flares, - flammable gas releases. • Top-down review following heavy landing on Claymore CAP in 1995 resulting in: - development of turbulence criterion, - production of joint industry helideck design guide, - research into visualisation of turbine exhaust plumes, - work on development of wind shear criterion planned.
Operations to Moving Helidecks • Pitch, roll and heave limits poor predictors of tipping or sliding on deck. • New deck acceleration-based motion severity index (MSI) developed. • Aerodynamic loads significant too - wind severity index (WSI) developed. • New MSI/WSI scheme: - directly related to risk of tipping/sliding, - independent of helideck location on vessel, - takes account of wind, - takes account of most likely motion for next 10 mins.
Helideck Lighting Research (1) • Questionnaire-based survey of offshore pilots. • Helideck difficult to locate due to colour of lighting. • Floodlights cause glare and loss of night vision. • Centre of helideck inadequately lit - ‘black hole effect’. • Visual cues from floodlightingshort range only.
Helideck Lighting Research (2) • Revised green perimeter lighting well received, being implemented by industry and adopted by ICAO. • Lit circle provides approach cues from 0.5NM. • Lit ‘H’ provides final approach cues from 0.25NM. • Lit circle and ‘H’ adopted by ICAO as alternative to floodlighting. • In-service trials planned for winter 2006/7.
Helicopter Flight Operations Monitoring • Adaptation of existing fixed wing scheme to helicopters. • Harder to define normality and hence abnormal situations. • In-service trials very successful. • Voluntary implementation in UK and Norway. • Adopted as Recommended Practice by ICAO. • Current work focused on enhancements: - low airspeed measure, - helideck environment monitoring.
Offshore Approaches • Weather radar: - not designed or certificated for task. - weather radar approaches not user- friendly. • Dedicated trials of differential GPS successfully performed. - key performance parameters are availability and integrity. - effects of rotors on GPS reception could be significant – reduced availability. - SBAS (I.e. EGNOS in Europe) could provide the solution. • Need for new equipment to cope with variable final approach track.
Concluding Remarks • Well-founded joint industry research programme. • Over 20 problem areas addressed. • Voluntary implementation of results by industry. • Major improvement in airworthiness through health monitoring (HUMS). • Significant operational safety benefits through flight data monitoring (FDM). • Further projects near to delivering additional safety benefits. • New joint industry funded initiatives under consideration. • Broader participation welcomed.
Finally…… For more information on the UK CAA-run helicopter safety research programme see - www.caa.co.uk and/or contact - dave.howson@srg.caa.co.uk Any questions?