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
B-17G "Flying Fortress" No. 44-83690 B-17G "Flying Fortress" No. 44-83690 B-17G-95-DL "Flying Fortress" No. 44-83690 is a historic B-17 Flying Fortress Heavy bomber located at the Aviation Museum, Grissom Air Force Base in Pipe Creek Township, Miami County, Indiana. It was built by the Douglas Aircraft Company and delivered for use on May 9, 1945. It was flown to Grissom Air Force Base for display as a museum piece in 1961, and subsequently restored. It was listed on the National Register of Historic Places in 1993. It was moved to the Museum of Aviation in Warner Robins, Georgia in August 2015. 44-83690 is a G-series