This is the US Army Air Corps Shield. Considering that Captain America I think worked closely with the army in WWII and probably did a fair amount of parachute drops out of planes, maybe an adaptation of elements of this insignia could be used for the wings on his helmet? Just make the wings white instead of gold and place them on the sides of the helmet?
![[Image: 500px-Us_army_air_corps_shieldsvg.png]](http://img.photobucket.com/albums/v28/Logan_Darklighter/500px-Us_army_air_corps_shieldsvg.png)