Nomads and hoverboy, I'd be interested if you can tell me where I can get more information on the helmets you mention and where I could purchase one (especially in UK).
I well remember the incident of which John Eacott speaks, it happened in 1967 at RNAS Culdrose. There was also a nasty accident on HMS Bulwark in 1968 when a Wessex V with an underslung load, just coming to the hover over the deck, suffered an engine runaway up, with that engine being shut down by the overspeed trip system. The aircraft crashed on to the deck, the main rotor departed into the Mediterranean, and the main gearbox partially detached from its mounting and part of it entered the cockpit. The pilot's life was saved by his 'bonedome' which had the appearance of the shell of a hard-boiled egg which has just been cracked prior to being peeled.
I must say that after I left the military I felt naked without a bone dome. One of my friends lost his licence when a 58ET he was flying in the North Sea in 1976 lost its tail rotor because of tail rotor buzz just as he was coming into the hover over a production platform deck. The aircraft fell off the rig deck onto the deck of a crane barge below. His skull was fractured when it was impacted by the corner of the overhead console and it was a number of years before he regained his licence. I think that a helmet would undoubtedly have saved him all those hard years of suffering. There was a fair amount of debate afterwards as to whether pilots should wear helmets, the management of the company arguing that if pilots wore them then they would have to be provided for passengers also (so what!); and that as offshore flying was public transport it was unnecessary, as one did not see pilots of passenger fixed-wing wearing them (they failed to mention that one also did not see the pilots of fixed-wing landing on moving rigs offshore at night in 60 knot winds!). However, they failed to mention that most passengers are not sitting in helicopters for 500+ hours a year as are most of we drivers-airframe. The matter was never properly resolved, but when I was flying on mountain ops in Iran we were provided with Gentex helmets which were comfortable even in temperatures well into the mid forties centigrade. On the operation where I am now the choice is left to the individual and quite a few pilots wear helmets. Certainly I notice that with the passage of the years the increasingly unpadded pate suffers a lot more from being bashed on the rotor brake and the numerous other overhead protuberances on most helicopters. A helmet would help there. Also, with advancing years, for most of us, comes deteriorating eyesight and as most helmets are provided with a dark visor there is no need to be constantly taking off normal spectacles and putting on sunglasses (which anyway are very expensive if one has them with prescription lenses). I also think that a helmet visor would be less likely to suffer from condensation than a pair of sunglasses, being a bit further from the face and having better air circulation.
The point of the clear visor on most helmets providing good protection from bird strikes is also very valid, especially on those helicopters with perspex screens. I have seen at least 4 bird strikes on company helicopters in the last 3 years and the fact that the pilots were at least wearing sunglasses gave some protection to their eyes. If they had had no eye protection I think that at least one of them would have been blinded in one eye.
I don't wear a helmet at present, but I would like to and if the 2 gentlemen mentioned above could send me some details I'd be most grateful. Incidentally, do any of the helmet manufacturers provide ANR earpieces, or is the increased level of hearing protection sufficient to render this unnecessary?