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
B-17G "Flying Fortress" No. 44-83690 and in 1961, flown to Grissom Air Force Base (then known as Bunker Hill) for permanent display. The Heritage Museum Foundation, established in 1981 as part of the Air Force Museum Program, maintains 44-83690. In 2015 the aircraft was moved to the Museum of Aviation at Robins AFB, Georgia and is currently undergoing a lengthy restoration. B-17G "Flying Fortress" No. 44-83690 is a reasonably intact example of a World War II aircraft type of which only 50 exist in the world. It is also an example of an experimental craft, which participated, in military tests shortly after World War II.