Boeing YB-40 Flying Fortress Boeing YB-40 Flying Fortress The Boeing YB-40 Flying Fortress was a modification for operational testing purposes of the B-17 Flying Fortress bomber aircraft, converted to act as a heavily armed gunship for other bombers during World War II. At the time of its development, long-range fighter aircraft such as the North American P-51 Mustang were just entering quantity production, and thus were not yet available to accompany bombers all the way from England to Germany and back. Work on the prototype, Project V-139, began in September 1942 by converting the second production B-17F-1-BO (serial number 41-24341) built. Conversion work was
Jagdgeschwader 1 (World War II) aircraft and were removed later in the year. By the start of 1943, JG 1 were mainly equipped with the Fw 190-A, excepting I./JG 1 still using the Bf 109G-1. The first large-scale air battle between JG 1 and VIII Bomber Command occurred when the latter bombed the naval base at Wilhelmshaven on 27 January 1943 with a force of 64 B-17 Flying Fortress (B-17) and 27 B-24 Liberators (B-24). Facing them were I., II. and IV./JG 1. With their Jever base below the route I./JG 1 attacked in full strength under "Hauptmann" Günther Beise. In broken cloud cover, they