Attached Link: http://www.garciaaviation.com/flyingg.html

The "Authentic Pilot 50 Mission AAC Crush Cap" shown here was typical of what the hats looked like. Unlike the officer hats worn by other Army branches which had re-inforced liners to make them look perfect- the USAAF pilots had a "crush cap" version because they usually wore headsets over the hat... This was the 1940's version of "cool". Wearing a crush cap meant you were an aviation-guy, not subject to regular Army regulations, and even non-pilots went out of their way to have the "crush-cap" look. You could probably pick up more girls in nightclubs with this hat...