Hmm.
I thought helicopter pilots wear helmets for communications? I don't know what the fast-jet chaps use them for.
I'd agree about the aviation helmets I've seen not being a patch on biker's helmets - I've come off my bike and was fine with my helmet. Aviation ones look flimsy.
Which is why I thought they were for communication and keeping warm!
BTW 4/5 point harnesses are the only viable solution. When I first saw the "lap strap" in the Cessna I used to fly I thought it was dangerous. before that I'd had a couple of flights in a friends Robin HR200 with 5-point harness.
WF.