Ok, so let's switch it up a bit. How about helmets while flying? I have helmets for .mil flying (two actually, one for pointy-nose and one for helos) and considered getting one of those light civilian flight helmets when I had a tail-dragger, since I didn't entirely trust the structure to hold the harness and I figured off-airport landings and ground-loops might increase the odds of a head-strike inside the cockpit. My Cherokee has a shoulder-strap now, but I suspect it wouldn't stand up too much force. Of course, I'd feel like a dumbass wearing a helmet in a Cherokee, but I wonder if a reasonable argument couldn't be made for one in bad turbulence or to improve survivability in lower-energy crashes. I wonder what percentage of aviation fatalities are due to a head-injury which might have been survivable with a helmet?