USAAF Type M-3 Flak Helmet

Head injuries to aircrew were usually serious and frequently fatal. Adopted in 1943, the M-3 featured cut outs over the ears and hinged flaps to accommodate the headphones built into flying helmets.

A study of USAAF bomber crew casualties in 1942 revelled that 70% were from low velocity projectiles, mainly flak fragments or secondary fragments like parts of airframe. Many crews took to wearing the standard army issue M-1 steel helmets but the fit over their flying helmets was poor. Some units adapted M-1 helmets by cutting away sections so they would fit over the telephone receivers of the flying helmets.