Boeing XB-38 Flying Fortress The XB-38 was destroyed and the project was canceled, in part because the V-1710 engines were needed for other projects such as the Lockheed P-38 Lightning, Bell P-39 Airacobra, Curtiss P-40 Warhawk, North American P-51A Mustang, and Bell P-63 Kingcobra fighters. Boeing XB-38 Flying Fortress The XB-38 Flying Fortress was a single example conversion of a production B-17E Flying Fortress, testing whether the Allison V-1710 V type engine could be substituted for the standard Wright R-1820 radial engine during early World War II. The XB-38 was the result of a modification project undertaken by Boeing and Vega (a subsidiary of
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