Northrop YB-49

The Northrop YB-49 was an American prototype jet-powered heavy bomber developed by Northrop Corporation shortly after World War II for service with the United States Air Force. The YB-49 featured a flying wing design and was a turbojet-powered development of the earlier, piston-engined Northrop XB-35 and YB-35. The two YB-49s built were both converted YB-35 test aircraft.

The YB-49 never entered production, being passed over in favor of the more conventional Convair B-36 piston-driven design. Design work performed during the development of the YB-35 and YB-49 nonetheless proved invaluable to Northrop decades later when the company was tasked with developing the B-2 stealth bomber, which entered service in the early 1990s.

Design and development

thumb|YB-49 takes to the air for the first time.

With the XB-35 program seriously behind schedule by 1944, and the end of piston-engined combat aircraft in sight, the production contract for this propeller-driven type was cancelled in May of that year. Nevertheless, the Flying Wing design was still sufficiently interesting to the Air Force that work was continued on testing a single YB-35A production aircraft.

During flight tests in the 1940s, it was noticed that the aircraft had a small radar cross-section, due to its flying wing design. Decades later, this stealthy detail would prove crucial to the design of Northrop Grumman's advanced, all-wing B-2 bomber.

On 9 February 1949, the first YB-49 flew from Muroc Air Force Base in California to Andrews Air Force Base near Washington, D.C., in 4 hours 25 minutes, after which President Truman ordered a flyby of Pennsylvania Avenue at rooftop level.). It was powered by six jet engines, two of them externally mounted in under-wing pods, ruining the aircraft's sleek, aerodynamic lines, but extending its range by carrying additional fuel. The use of jet engines had resulted in considerably increased fuel consumption and decreased its range significantly below that of the rival Convair B-36. His son, John Northrop Jr., later recounted during an interview his father's devastation and lifelong suspicion that his Flying Wing project had been sabotaged by political influence and back room wheeling-and-dealing between Convair and the Air Force.

thumb|Northrop YRB-49A with six engines, two of which are mounted externally

The sole prototype reconnaissance platform, the YRB-49A, first flew on 4 May 1950. After only 13 flights, testing ended abruptly on 26 April 1951. It was then flown back to Northrop's headquarters from Edwards Air Force Base (formerly Muroc AAF) on what would be its last flight. There, this remaining flying wing sat abandoned at the edge of Northrop's Ontario airport for more than two years. It was finally ordered scrapped on 1 December 1953.

In a 1979 videotaped news interview, Jack Northrop broke his long silence and said publicly that all Flying Wing contracts had been canceled because Northrop Aircraft Corporation refused to merge with competitor Convair at Air Force Secretary Stuart Symington's strong suggestion, because, according to Jack Northrop, Convair's merger demands were "grossly unfair to Northrop." Allegations of political influences in the cancellation of the Flying Wing were investigated by the House Armed Services Committee, where Symington publicly denied exerting pressure on Northrop to merge.

Northrop's Flying Wing program may have been terminated due to its technical difficulties and the program being behind schedule and over budget. Another possible contributing factor to the cancellation may have been Northrop spreading its small engineering staff too widely in other experimental programs. While the competing propeller-driven Convair B-36 "Peacemaker" was an obsolete World War II-era design by this time, and had been having just as many or even more development problems, the Air Force seemed to have greater confidence that its more conventional design and "teething" problems could be overcome, when compared to those of the more radical Flying Wing. While the YB-49 had well-documented performance and design issues, the B-36 program needed more development money. When the YB-49 jet bomber was canceled, Northrop was awarded a much smaller, lower profile production contract for its straight-winged F-89 Scorpion fighter as compensation for the canceled Flying Wing.

The YB-49 and its modern counterpart, the B-2 Spirit, both built either by Northrop or Northrop Grumman, have the same wingspan: 172.0 ft (52.4 m). Flight test data collected from the original YB-49 test flights were used in the development of the B-2 bomber. Shortly before his death in February 1981, Jack Northrop learned from the Northrop Corporation of the company's flying wing bid for the future B-2; he remarked: "I know why God has kept me alive for the past 25 years." The new bomber would be publicly displayed for the first time in 1988.

Notable appearances in media

Paramount Pictures' 1953 film, The War of the Worlds, depicts a YB-49 dropping an atomic bomb on the invading Martians. The feature film, produced by George Pal and directed by Byron Haskin, incorporates Northrop color footage of a YB-49 test flight, originally used in Paramount's Popular Science theatrical shorts of the era.

Specifications (YB-49)

400px|right|cross section drawing of the Northrop YB-35B