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,
Technology during World War II fighter planes. American bomber planes such as the B-17 Flying Fortress had been built before the war as the only adequate long-range bombers in the world, designed to patrol the long American coastlines. Defended by as many as six machine-gun turrets providing 360° cover, the B-17s were still vulnerable without fighter protection even when used in large formations. Despite the abilities of Allied bombers, though, Germany was not quickly crippled by Allied air raids. At the start of the war the vast majority of bombs fell miles from their targets, as poor navigation technology ensured that Allied airmen frequently could