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
Military history of the United Kingdom during World War II for the launching of Operation Overlord on 6 June 1944. Following Overlord, further direct support was provided to the troop, but Harris eventually succeeded in detaching his command from Eisenhower's control. The striking of German cities resumed. By the winter of 1944, the power of the British and American bomber forces had grown enormously. It was now routine for 1,000 bomber raids to be mounted by both American and British forces flying from the UK. American forces flying from Italy could also put several hundred aircraft above a target. Accuracy had improved, but it was still nowhere near good enough