A 1942 study found that 70% of bomber crew wounds were caused by low-velocity projectiles, such as deflected flak fragments or shattered aircraft parts. The introduction of flak jackets significantly reduced injuries from these threats, saving thousands of bomber crewmen during World War II.
The U.S. Army Eighth Air Force pioneered the development of modern body armor, including flak vests made with manganese steel plates sewn into canvas. These vests were particularly effective against shrapnel and flak, though they offered limited protection against high-velocity rounds.
During World War II, studies showed that flak jackets significantly reduced injuries among bomber crews. A 1943 report from the U.S. Army Eighth Air Force found that these vests prevented 50-60% of wounds caused by shrapnel and low-velocity projectiles.
Later testing in the Korean War showed that newer body armor designs stopped 75.7% of all fragments and 24.4% of small arms projectiles. These advancements saved thousands of lives and influenced modern protective gear.