In over 40 years of offshore operations in the UK sector alone, well over a million flights have been made and easily over 10 million passengers have been transported, by very conservative calculations. For these civilian flights, not once has the absence of helmets been a safety issue in the few ditchings which have occurred.
The logistics of fitting and maintaining helmets for every passenger, which would have to be the case if pilots were forced to wear them, would be difficult to justify in the light of the historical statistics. If passengers were issued only lightweight canoeing style helmets, they could justifiably ask why the pilots get fitted with something more robust.
Furthermore the public address systems in offshore large helicopters are not of the highest quality. As things are, we frequently get complaints from passengers about poor p.a., so close-fitting helmets are just going to make the hearing of emergency announcements worse. I don't believe that fitting earphones to passenger helmets is practicable. (Certification, wiring, radio interference, etc.)
As for all the other safety stuff like immersion suits, flotation, liferafts and EPIRBs employed in offshore transportation, the assumption must be that when ditching on water there aren't going to be violent collision forces such as could knock people unconscious.
Basically if you hit the water hard enough to knock aircraft occupants about violently, then floats will be torn off, capsize is virtually certain and retrieving liferafts almost impossible.
No doubt you could refer to the Cougar S92 disaster and make suppositions about why one passenger survived. Possibly, or even probably, the wearing of helmets could have saved more. But it's such an extremely isolated case in the history of offshore operations.
Last edited by Colibri49; 9th Nov 2011 at 10:31.