Boeing XB-38 Flying Fortress 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 Lockheed) on a B-17 Flying Fortress to fit it with liquid-cooled Allison V-1710-89 Vee engine. It was meant as an improved version of the B-17, and a variant that could be used if air-cooled Wright R-1820 radial engines became scarce. Completing
Military history of the United States during World War II American bomber crew losses were high. One such example was the Schweinfurt-Regensburg mission, which resulted in staggering losses of men and equipment. The introduction of the revered P-51 Mustang, which had enough fuel to make a round trip to Germany's heartland, helped to reduce losses later in the war. In mid-1942, the United States Army Air Forces (USAAF) arrived in the UK and carried out a few raids across the English Channel. The USAAF Eighth Air Force's B-17 bombers were called the "Flying Fortresses" because of their heavy defensive armament of ten to twelve machine guns, and armor plating in