AUK study of safety and survival in offshore helicopter operations looks certain to lead to an acceleration of basic changes in safety-equipment design.
The biggest changes are likely to be in the areas of life-raft carriage, aircraft-flotation devices and lifejacket/immersion-suit design.
Moves towards the use of personal underwater-breathing equipment and the prohibition of offshore flight in weather unsuitable for ditching have been dismissed as impractical.
The study, the Review of Helicopter Offshore Safety and Survival (RHOSS), was commissioned by the UK Civil Aviation Authority following the March 1992 crash of a Eurocopter AS.332L Super Puma close to the Cormorant Alpha rig. Five passengers failed to escape and another six died in the water after escaping.
The RHOSS committee produced 17 recommendations towards post-accident survival, as opposed to accident prevention, and notes that the North Sea industry has a generally good survival record, with only 19 fatalities in "survivable accidents" in 18 years.
The study distinguishes between "ditching" under control into a non-hostile sea and "crashing" out of control or into a hostile sea. He stresses that "...nobody has been killed in a ditching as we have defined that".
Bond Helicopters is now flying a Super Puma conversion kit which puts liferafts outside the machine, as favoured by the RHOSS team, rather than the "inside" configuration. The CAA is now to review and develop specific proposals.
The CAA is also to look again at possible research into improved flotation mechanisms, including aids to buoyancy, and improved deployment procedures. The RHOSS is now almost certain to recommend that the wearing of immersion suits for passengers becomes mandatory, and that extensive work is carried out into integration of immersion suits and life-saving jackets (LSJs).
Immersion suits are compulsory for crews and, in practice, always worn by passengers. The lack of regulation, however, has led to incompatibility between the suits and LSJs - as in the Cormorant Alpha accident, where survivors had difficulty in preventing their LSJs riding up around their necks.
Standardisation of immersion suits would allow crotch-straps for LSJs to be compulsory. The CAA has prepared a draft directive.
Source: Flight International
