"Stuart & Kathryn Fields" wrote:

A friend of mine finally gave in and bought a helmet to
use in lieu of his $1,000 Bose units.

Mythbusters has an episode showing what happens when a chicken cannon
gets used on the windscreen of a GA type airplane.

They were surprised that it when right through and did damage to buster
their dummmy.

They were under the impression that the windscreens in small airplanes
where made out of some sort of shatterproof or shatter resistant glass
or plastic.