Original U.S. Vietnam War Era Named APH-5 Helicopter Pilot Flying Helmet by Sierra Engineering Company With Early “Bowling Ball” Storage Bag - Size Large Caps & Hats but the important marking is

but the important marking is on the control at the top of the right side

with overall wear

marked with Size 56 and dated 1944

This company had it covered in gold leaf and used as the Golden Helmet Trophy for the British Formula Ford Championships

This is an incredible Czech Issue Sa 24 vz

Original U.S. Vietnam War Era Named APH-5 Helicopter Pilot Flying Helmet by Sierra Engineering Company With Early “Bowling Ball” Storage Bag - Size Large Caps & Hats but the important marking isOriginal Item: Only One Available. This is a nice example of a Vietnam War APH 5 Flying Helmet, as used by all branches of service during the Vietnam War. This Helmet appears to have been very well used, and repainted multiple times during its period of service. Has a functional tinted visor as well as boom mic and ear padding. Size is a LARGE and comes in its original Early War Bowling Ball storage bag, a rare piece to find with this helmet. There is