I have always been under the impression that wearing a good flight helmet would go a long ways in saving your butt if you had a high G impact and crash. But, there is evidence that a helmet really won't do that much for you. Two recent crashes, a T-51 and a P-51, illustrate the point. Both crashes were fatal. In one case, the pilot was wearing a helmet. It did not save him. In the P-51, the passenger died from the impact. He was not wearing a helmet, but the UK authorities stated in the accident report that a helmet would not have saved him. So...what real good is a helmet? Unless your are a biker, then it makes a lot of sense.