Originally Posted by
SDB73
Problem is; If you protect your forehead with extra mass (eg. a helmet), your head will be thrown further forward in the same accident, and so will be more likely to impact the panel / sun visor, possibly on an unprotected area, like the face. Making the sun visor more padded would be a better solution in most cases.
Cloth Helmet + DC 10/30 = 705g
Large HGU/55P (Kevlar) + Oregon Aero Innards + CEP = 1128g
Weight of the average human head ~4500g
By my math, the total increased mass of head plus headgear increases by about 8% (depending on the size of your noggin) for taking the added protection afforded by the Gentex. Factor in not just the protection against a simple forward impact (for example when you jump over the side, slamming your head against parts of the airframe and, in due course, the ground) then it becomes a....er...no-brainer.
I know a chap who made a precautionary landing into a field in an Extra 300 a while back. His head (thankfully in a helmet) removed the throttle lever, amongst other things. By your logic, you would need to fill the cockpit entirely with foam rubber, rather than opt for the headgear.
But the decision is a personal one - but having some solid numbers to work on helps.