The Boeing B-50A Superfortress was the result of a program started in mid-1943 when Pratt & Whitney offered to adapt a B-29 for its more powerful R-4360 radial engines. The Army Air Forces accepted the offer, but only authorized conversion of a single aircraft strictly for test purposes. This aircraft was redesignated XB-44 when complete. Although the XB-44 had better performance than the B-29, no production plans were made for B-44s. The Army didn't want to disrupt B-29 production in favor of the B-44, and the end of World War II saw the rapid demobilization of the armed forces and the end of most wartime production. Although the end of WWII signaled the end of most production contracts, the Army still needed a long-range bomber capable of carrying atomic weapons.
Boeing engineers redesigned the basic B-29 airframe for the Pratt & Whitney engines using XB-44 specifications. They also designed a stronger wing and a taller vertical stabilizer for a production aircraft initially designated B-29D. An order for 200 aircraft placed just before WWII ended was in serious jeopardy of being canceled outright; however, the Army redesignated this design B-50A in December 1945. The designation change was partly due to the extensive design changes incorporated into the B-29D and partly to make the aircraft appear as a completely new design to gain funding for production. The plan worked and an initial contact was approved.
Seventy nine B-50As were ordered in 1946. The first flight was on June 25, 1947, followed by initial deliveries to the Air Force one year later. The first unit to get the B-50A was the 43rd Bomb Wing stationed at Davis-Monthan Air Force Base, Ariz. The last -A model was delivered in 1949 and the Strategic Air Command used them into the mid-1950s. About two-thirds of the B-50As were retrofitted with in-flight refueling equipment for receiving fuel from tanker aircraft. The Lucky Lady IIwas one of the modified aircraft, and it became the first aircraft to fly around the world nonstop.
B-29D renamed B-50A
TECHNICAL NOTES: Armament: 12 .50-cal. machine guns, one 20 mm cannon and 20,000 lbs. of bombs Engines: Four Pratt & Whitney R-4360-35 Wasp Major turbosupercharged radials of 3,500 hp each Maximum speed: 385 mph at 25,000 ft. and combat weight of 121,700 lbs. Cruising speed: 235 mph Range: 4,650 miles with 10,000-lb. bomb load; 5,270 miles maximum ferry range Service ceiling: 37,000 ft. Span: 141 ft. 3 in. Length: 99 ft. 0 in. Height: 32 ft. 8 in. Weight: 168,500 lbs. (maximum takeoff weight) Crew: 10 or 11 normally [pilot, copilot, flight engineer, navigator, bombardier, radar operator, radio operator, and four gunners (top, tail, left and right)] Serialnumbers: 46-002 to 46-060; 47-098 to 47-117