Boeing B-17 Flying Fortress NAN10-50.jpg|thumb|B-17 modified for testing of the [[Pratt & Whitney T34|XT-34 turboprop]]. When testing concluded, the aircraft was restored to stock configuration as the "[[Liberty Belle (B-17)|Liberty Belle]]", but was lost in a post-forced-landing fire near [[Oswego, Illinois]] on 13 June 2011.]] [[Category:Boeing aircraft|B-17 Flying Fortress]] [[Category:United States bomber aircraft 1930–1939]] [[Category:Four-engined tractor aircraft]] [[Category:Low-wing aircraft]] [[Category:World War II bombers of the United States]] [[Category:Boeing B-17 Flying Fortress| ]] [[Category:Aircraft first flown in 1935]] 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
B-17 Flying Fortress units of the United States Army Air Forces B-17 Flying Fortress units of the United States Army Air Forces This is a list of United States Army Air Forces B-17 Flying Fortress units of the United States Army Air Forces including variants and other historical information. Heavy bomber training organizations primarily under II Bomber Command in the United States and non-combat units are not included. The B-17 Flying Fortress was perhaps the most well-known American heavy bomber of the Second World War (1939/41-1945), . It achieved a fame far beyond that of its more-numerous contemporary, the Consolidated B-24 Liberator. The first pre-production Y1B-17 Fortress was delivered to the