B-17 Flying Fortress units of the United States Army Air Forces 2d Bombardment Group, Langley Field, Virginia on 11 January 1936; the first production B-17B was delivered on 29 March 1939 also to the 2nd Bombardment Group. A total of 12,677 production Fortresses was built before production came to an end. In August 1944, the Boeing B-17 equipped no less than 33 overseas combat groups. The last Boeing-built B-17G was delivered to the USAAF on 13 April 1945. Following the end of World War II, the Flying Fortress was rapidly withdrawn from USAAF service, being replaced by the B-29 Superfortress. Literally thousands of Fortresses used in combat in Europe by Eighth
Boeing B-17 Flying Fortress misgivings by the RAF that attempts at daylight bombing would be ineffective. As use by Bomber Command had been curtailed, the RAF transferred its remaining Fortress I aircraft to Coastal Command for use as a long-range maritime patrol aircraft, instead. These were later augmented in August 1942 by 19 Fortress Mk II (B-17F) and 45 Fortress Mk IIA (B-17E). A Fortress from No. 206 Squadron RAF sank U-627 on 1942, the first of 11 U-boat kills credited to RAF Fortress bombers during the war. The RAF's No. 223 Squadron, as part of 100 Group, operated a number of Fortresses equipped