In the middle of the Second World War, the Army Air Force felt the need of an aircraft which will be faster than the contemporary aircrafts and will carry heavy loads of conventional weapons in farther distance. B-29D at that time was in operation but could not meet these requirements.
As World War II ended, the production of B-29s was suspended. Only the B-29D, in the series, survived but its overall role changed. In December 1945, these B-29Ds were re-designated as the B-50 and was assigned for the important atomic role.
The Army Air Force wanted replacements of both B-36 and B-29s, though both of these aircrafts by than were modified to carry atomic bombs. The short-ranged B-50 was recognized as a temporary solution. The B-29D featured many changes before turning in into B-50. The re-designated aircraft, built with a stronger but lighter grade of aluminum, had larger flaps, a higher vertical tail, a hydraulic rudder boost, nose wheel steering, a efficient undercarriage retracting mechanism, and a new electrical device to remove the ice from the pilot’s windows. The new aircraft’s wings and empennage also could be thermally de-iced. Also, the four higher-thrust Pratt & Whitney R-4360 engines that replaced the standard B-29’s R-3350s; gave a power increase of 59 percent, and electrically controlled, reversible pitch propellers allowed the use of engine power as an aid to braking on short or wet runways.
The new B-50 had some limitations as well. The limitations included its small space and engine malfunctions. Quick development of special heavy weapons of that time created more complications. Another problem it had was the cracking of the metal skin on the trailing edge of the wings and flaps dictated extensive modifications. To make things worse, fuel tank overflows, leaking fuel check valves, troubles in engine turbo-chargers and generator defects were revealed. Moreover, most B-50s came off the production lines without the receiver end of the new air-to-air refueling system being developed by Boeing.
The B-50 was assigned the Boeing factory designation of Model 345-2. The first B-50 to be built was a
