seagull2200
I haven't read the entire thread (not enough time) but I think there is little point in wearing a helmet in a normal GA type in case of an accident.
If you have an accident during a deliberate ground contact (i.e. a landing) then usually you walk away from it. The plane might get wrecked but unless somebody does something drastically bad they are usually OK.
If you have an unintended ground contact, that is probably flying into a hill in poor visibility or in IMC, and at say 100kt a helmet will make no difference, because the plane will be obliterated.
I do know one man who went into a hill in IMC at (he says) about 120kt, at such an oblique angle that he just ended up in hospital for a while. But that is a one-off.
If you want to wear something, spend your money on the very best headset you can buy: a Bose X
Otherwise, spend it on the best GPS you can buy. <--- that comment will make this thread run and run, but I am getting out of here!!!