Boeing B-17 Flying Fortress Boeing B-17 Flying Fortress The Boeing B-17 Flying Fortress is a four-engined heavy bomber developed in the 1930s for the United States Army Air Corps (USAAC). Competing against Douglas and Martin for a contract to build 200 bombers, the Boeing entry (prototype Model 299/XB-17) outperformed both competitors and exceeded the air corps' performance specifications. Although Boeing lost the contract (to the Douglas B-18 Bolo) because the prototype crashed, the air corps ordered 13 more B-17s for further evaluation. From its introduction in 1938, the B-17 Flying Fortress evolved through numerous design advances, becoming the third-most produced bomber of all time,
76th Flying Training Wing (World War II) from single and two-engine aircraft to the B-17 or B-24 Liberator heavy bombers. Also after 1944, most pilots were learning on B-17/B-24s for eventual transition to B-29 Superfortress training under Second Air Force. As training requirements changed during the war, schools were activated and inactivated or transferred to meet those requirements. The schools of the wing flew primarily B-17D/E/F Flying Fortresses. Some B-17Gs were flown after June 1944 when Second Air Force B-17 training ended. Some B-24D Liberators were also used 76th Flying Training Wing (World War II) The 76th Flying Training Wing was a wing of the United States