Northrop YB-49

The Northrop YB-49 was a prototype jet-powered heavy bomber developed by Northrop Corporation shortly after World War II for service with the U.S. 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 actually 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 in the development of the YB-35 and YB-49 nonetheless proved to be valuable to Northrop decades later in the eventual development of the B-2 stealth bomber, which entered service in the early 1990s.

YB49-2 300
Role Strategic bomber
Manufacturer Northrop Corporation
Designer Jack Northrop
First flight 21 October 1947
Status Prototype only
Primary user United States Air Force
Number built 3 converted from YB-35
two YB-49
one YRB-49A
More incomplete examples scrapped
Developed from Northrop YB-35

Design and development

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.[1]

Among the aircraft later completed were two airframes that the Air Force ordered be fitted with jet propulsion and designated as YB-49s.[1] The first of these new YB-49 jet-powered aircraft flew on 22 October 1947 (from Northrop airfield in Hawthorne, CA) and immediately proved more promising than its piston engined counterpart. The YB-49 set an unofficial endurance record of staying continually above 40,000 ft (12,200 m) for 6.5 hours.[2]

The second YB-49 was lost on 5 June 1948, killing its pilot, Major Daniel Forbes (for whom Forbes Air Force Base was named), co-pilot Captain Glen Edwards (for whom Edwards Air Force Base is named), and three other crew members,[2] one of whom, 1st Lieutenant Edward Lee Swindell, was a crew member on the Boeing B-29 that assisted Chuck Yeager in breaking the sound barrier in the Bell X-1 aircraft. Their aircraft suffered structural failure, with both outer wing sections becoming detached from the center section. Speculation at the time was that the YB-49 was lost due to excessive pullout loads imposed on the heavy airframe when a scheduled flight test of the large bomber's stall recovery resulted in a sudden and dramatic high-speed, nose-over dive. The post-stall high-speed dive resulted from the clean, low-drag, all-wing design, which gave the YB-49 a rapid speed increase in any type of dive. Fellow YB-49 test pilot Robert Cardenas later claimed that the YB-49 rotated backwards in stall, and that he warned Edwards about it. Jack Northrop later countered that such a behavior was impossible for the all-wing design.[3]

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.[4][5]

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,[2] after which President Truman ordered a flyby of Pennsylvania Avenue at rooftop level.[3] The return flight from Andrews was marred when four of the eight engines had to be shut down due to oil starvation. Inspection after a successful emergency landing at Winslow Airport, Arizona, revealed no oil had been replaced in these engines at Wright after the Muroc-to-Andrews leg,[2] raising a suspicion of industrial sabotage.[1]

The last operational YB-49 prototype was destroyed on 15 March 1950, during high-speed taxi trials at Muroc Field. The nose wheel began to encounter severe vibration problems and finally collapsed;[2] the aircraft was completely destroyed in the ensuing fire. The taxi trials took place with the YB-49's fuel tanks full, an unusual testing procedure, fanning further speculation of industrial sabotage of the aircraft.[1]

The Air Force ordered the remaining uncompleted YB-35 piston-engined airframes be completed as production B-35B aircraft.

Bombing target tests showed a tendency of flying wings to "hunt" in yaw after turns and when flying in "disturbed" air, degrading bombing accuracy. It was thought that one of the new Honeywell autopilots, with yaw damping, would correct this flaw. Northrop chief test pilot on the YB-35 and YB-49 programs Max Stanley contends in the 1992 Discovery Channel documentary "The Wing Will Fly", the adaptation of the autopilot in this dual function "damped out the directional oscillations to the degree where... I think you would say it met the (military) specifications." Brig. General Robert Cardenas also flew the YB-49 during many of its test flights, praising the aircraft for its marvelous performance, while also noting the YB-49 required a very long bomb run to dampen out directional oscillations. Many of these challenges would eventually be overcome when fly-by-wire systems were developed in the 1950s, which were first used in regular production for the Convair B-58 Hustler and then when computer-generated artificial stability became available in the 1970s, culminating in the development of the all-wing Northrop Grumman B-2 Spirit Stealth Bomber.

The conversion of the long-range XB-35 to jet power essentially cut the effective range of the aircraft in half, putting it in the medium-range bomber category with Boeing's new swept-winged jet bomber the B-47 Stratojet. The B-47 was optimized for high-altitude and high-speed flight and, in an era where speed and altitude were becoming the name of the game, the YB-49's thick airfoil could never be maximized for high-speed performance. In the same Discovery Channel documentary, former Air Force Flight Test Center Historian Dr. James Young states his opinion that while political gamesmanship and back room dealing certainly played a role in the aircraft's demise, the Flying Wing program was ultimately cancelled for solid technological reasons.

Operational history

In June 1948, the Air Force ordered the type into full production as the RB-49A reconnaissance aircraft (company designations N-38 and N-39[6]).[1] 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.[1] One YB-35 airframe (s/n 42-102369) was chosen as the prototype for the RB-49 and designated YRB-49A.

During early 1950, the remaining YB-35Bs airframes being converted to YRB-49As were ordered scrapped. Flight testing of the sole remaining YB-49 prototype ended 14 March 1950. On 15 March 1950, that program was canceled, and coincidentally, that last YB-49 prototype suffered a high-speed taxiing accident and, as previously noted, was totally destroyed in the ensuing fire.

Only two months later, all Flying Wing contracts were canceled abruptly without explanation by order of Stuart Symington, Secretary of the Air Force. Shortly thereafter, also without explanation, Symington turned down a request from the Smithsonian for the Air Force to donate one of these big wings to its collection of pioneering Northrop aircraft.[7]

All remaining Flying Wing bomber airframes, except for the sole YRB-49A reconnaissance version, were ordered chopped up by Symington, the materials smelted down using portable smelters brought to Northrop's facility, in plain sight of its employees. Jack Northrop retired from both the company he founded and aviation shortly after he saw his dream of a pure, all-wing aircraft destroyed.[8] 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.[9]

YRB-49A with its eight engines replaced with six
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 (formally Muroc) 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.[10]

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."[11] Shortly thereafter, Symington became president of Convair upon leaving his post as Secretary of the Air Force.[7] 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.[7]

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.[12] At one time, it appeared the B-36 program might be canceled as well. But the Air Force and the Texas Congressional delegation desired to have a production program for their large Fort Worth aircraft production factory, and Convair had much more effective lobbyists in Washington DC. The Northrop Corporation was always a technological trailblazer, but the independent nature of Jack Northrop often collided with the political wheeling-and-dealing in Washington, which gravitated toward massive military appropriations; consequently, the obsolete Convair B-36 prevailed. 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.[13][14]

The YB-49 and its modern counterpart, the B-2 Spirit, both built by 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.

Thirty years later, in April 1980, Jack Northrop, then quite elderly and using a wheelchair, was taken back to the company he founded. There, he was ushered into a classified area and shown a scale model of the Air Force's forthcoming, but still highly classified Advanced Technology Bomber, which would eventually become known as the B-2; it was a sleek, all-wing design. Looking over its familiar lines, Northrop, unable to speak due to various illnesses, was reported to have written on a pad: "I know why God has kept me alive for the past 25 years." Jack Northrop died ten months later, in February 1981, eight years before the first B-2 entered Air Force service.[15]

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.[16]

A modified YB-49 appears in Clive Cussler's novel Blue Gold, where it has been preserved at an abandoned airfield in Alaska and is rediscovered during a search for its top-secret cargo.[17]

Specifications (YB-49)

YB49-6 300
YB-49 takes to the air for the first time.
YB49-9 300
Partially completed YB-35B airframes lined up for completion or conversion to YRB-49As.

Data from National Museum of the United States Air Force,[10] and U.S. Standard Aircraft Characteristics[18][19]

General characteristics



  • Guns: 4 × .50 in (12.7 mm) machine guns (to be mounted in rotating "stinger" tail cone on all production aircraft)
  • Bombs: 16,000 lb (7,260 kg) of ordnance

See also

Related development

Aircraft of comparable role, configuration and era

Related lists



  1. ^ a b c d e f Pattillo 2001, p. 185.
  2. ^ a b c d e Wooldridge, E.T. "The Northrop bombers." Century of Flight, 2003. Retrieved: 22 October 2010.
  3. ^ a b "Modern Marvels: Extreme Aircraft s11-e33", 21-26min. History Channel, 25 August 2004. Retrieved: 25 August 2012.
  4. ^
  5. ^ "Popular Science". September 1986.
  6. ^ Chong, Tony, 2016. Flying Wings & Radical Things: Northrop’s Secret Aerospace Projects & Concepts 1939-1994. Forest Lake, Minnesota: Specialty Press.
  7. ^ a b c Pattillo 2001, p. 153.
  8. ^ Pattillo 2001, p. 186.
  9. ^ Honey, John. "The Wing Will Fly." Broadcast on The Discovery Channel: 1991.
  10. ^ a b "Fact sheet: Northrop YRB-49A." National Museum of the United States Air Force. Retrieved: 29 October 2010.
  11. ^ Fitzsimons 1978, p. 2282.
  12. ^ Donald 1997, p. 709.
  13. ^ Donald 1997, p. 708.
  14. ^ Jones 1975, p. 238.
  15. ^ Withington and Davey 2006, p. 12.
  16. ^ Howe, Tom. "Northrop YB-49 Flying Wing." Retrieved: 25 August 2012.
  17. ^ Cussler, Clive (2000). Blue Gold. Simon and Schuster. p. 282.
  18. ^ "Standard Aircraft Characteristics: YB-49 Flying Wing" (PDF). US Air Force. 20 December 1949. Retrieved 2 November 2016.
  19. ^ Northrop YB-49 Flying Wing Bomber page 14
  20. ^ Winchester 2005, p. 193.


  • Coleman, Ted. Jack Northrop and the Flying Wing: The Real Story Behind the Stealth Bomber. New York: Paragon House, 1988. ISBN 1-55778-079-X.
  • Donald, David, editor. "Northrop Flying Wings". Encyclopedia of World Aircraft. Etobicoke, Ontario: Prospero Books, 1997. ISBN 1-85605-375-X.
  • Fitzsimons, Bernard, ed. "Scorpion, Northrop F-89." Illustrated Encyclopedia of 20th Century Weapons and Warfare, Volume 21. London: Phoebus, 1978. ISBN 0-8393-6175-0.
  • Maloney, Edward T. Northrop Flying Wings. Corona del Mar, California: World War II Publications, 1988. ISBN 0-915464-00-4.
  • O'Leary, Michael. "Wings of Northrop, Conclusion". Air Classics, Volume 44, Number 3, March 2008, Challenge Publications, Inc. ISSN 0002-2241. (Heavily illustrated, authoritative YB-49 article)
  • Pape, Garry and John Campbell. Northrop Flying Wings: A History of Jack Northrop's Visionary Aircraft. Atglen, Pennsylvania: Schiffer Publishing, Ltd., 1995. ISBN 0-88740-689-0.
  • Pattillo, Donald M. "Pushing the Envelope: The American Aircraft Industry". Ann Arbor, Michigan: University of Michigan Press, 2001. ISBN 0-472-08671-5.
  • Winchester, Jim. "Northrop XB-35/YB-49" Concept Aircraft: Prototypes, X-Planes and Experimental Aircraft. Kent, UK: Grange Books plc., 2005. ISBN 978-1-84013-809-2.
  • Withington, Thomas and Chris Davey. B-2A Spirit Units in Combat. Oxford, UK: Osprey Publishing, 2006. ISBN 1-84176-993-2.
  • Wooldridge, E. T. Winged Wonders: The Story of the Flying Wings. Washington, D.C.: Smithsonian Institution Press, 1983. ISBN 0-87474-966-2.

External links

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Like the J33, the design of the J35 originated at General Electric, but major production was by the Allison Engine Company.

AmeriPlanes Mitchell Wing A-10

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Bundesstraße 49, a German road

B49 (New York City bus) in Brooklyn in the United States

HLA-B49, an HLA-B serotype

a postcode area in Alcester, Warwickshire, England

Northrop YB-49, an American aircraft

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Persiaran Mokhtar Dahari, in Selangor, Malaysia

Daniel Forbes

Daniel Hugh Forbes, Jr. (June 6, 1920 - June 5, 1948) was an American aviator.

Edwards Air Force Base

Edwards Air Force Base (AFB) (IATA: EDW, ICAO: KEDW, FAA LID: EDW) is a United States Air Force installation located in Kern County in southern California, about 22 miles (35 km) northeast of Lancaster, 15 miles (24 km) east of Rosamond and 5.5 miles (8.9 km) south of California City.

It is the home of the Air Force Test Center, Air Force Test Pilot School, and NASA's Armstrong Flight Research Center. It is the Air Force Materiel Command center for conducting and supporting research and development of flight, as well as testing and evaluating aerospace systems from concept to combat. It also hosts many test activities conducted by America's commercial aerospace industry.

Notable occurrences at Edwards include Chuck Yeager's flight that broke the sound barrier in the Bell X-1, test flights of the North American X-15, the first landings of the Space Shuttle, and the 1986 around-the-world flight of the Rutan Voyager.

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The fuselage (; from the French fuselé "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, and cargo. In single-engine aircraft it will usually contain an engine, as well, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage, which in turn is used as a floating hull. The fuselage also serves to position control and stabilization surfaces in specific relationships to lifting surfaces, which is required for aircraft stability and maneuverability.

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Horten brothers

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Jack Northrop

John Knudsen "Jack" Northrop (November 10, 1895 – February 18, 1981) was an American aircraft industrialist and designer, who founded the Northrop Corporation in 1939.

His career began in 1916 as a draftsman for Lockheed Aircraft Manufacturing Company (founded 1912). He joined the Douglas Aircraft Company in 1923, where in time he became a project engineer. In 1927 he rejoined Lockheed, where he was a chief engineer on the Lockheed Vega transport. He left in 1929 to found Avion Corporation, which he sold in 1930. Two years later, he founded the Northrop Corporation. This firm became a subsidiary of Douglas Aircraft in 1939, so he co-founded a second company named Northrop.

List of flying wings

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Northrop Corporation

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Northrop N-1M

The Northrop N-1M, also known by the nickname "Jeep", was an American experimental aircraft used in the development of the flying wing concept by Northrop Aircraft during the 1940s.

Northrop N-9M

The Northrop N-9M was an approximately one-third scale, 60-ft span all-wing aircraft used for the development of the full size, 172-ft wingspan Northrop XB-35 and YB-35 flying wing long-range, heavy bomber. First flown in 1942, the N-9M (M for Model) was the third in a lineage of all-wing Northrop aircraft designs that began in 1929 when Jack Northrop succeeded in early experiments with his single pusher propeller, twin-tailed, twin-boom, all stressed metal skin Northrop X-216H monoplane, and a decade later, the dual-propeller N-1M of 1939–1941. Northrop's pioneering all-wing aircraft would lead Northrop Grumman many years later to eventually develop the advanced B-2 Spirit stealth bomber, which debuted in 1989 in US Air Force inventory.

Northrop YB-35

The Northrop XB-35 and YB-35 were experimental heavy bomber aircraft developed by the Northrop Corporation for the United States Army Air Forces during and shortly after World War II. The airplane used the radical and potentially very efficient flying wing design, in which the tail section and fuselage are eliminated and all payload is carried in a thick wing. Only prototype and pre-production aircraft were built, although interest remained strong enough to warrant further development of the design as a jet bomber, under the designation YB-49.

The War of the Worlds (1953 film)

The War of the Worlds (also known in promotional material as H. G. Wells' The War of the Worlds) is a 1953 American Technicolor science fiction film from Paramount Pictures, produced by George Pal, directed by Byron Haskin, and starring Gene Barry and Ann Robinson.

The film is a loose adaptation of the novel of the same name by H. G. Wells, the first of five film adaptations. It is a modern retelling of the 1897 novel, changing the setting from Victorian era-England to 1953 southern California. Earth is suddenly and unexpectedly invaded by Martians, and American scientist Clayton Forrester searches for any weakness that can stop them.

The War of the Worlds won an Academy Award for Best Visual Effects and went on to influence other science fiction films. In 2011, it was selected for preservation in the United States' National Film Registry in the Library of Congress, being deemed "culturally, historically, or aesthetically significant".

William R. Sears

William Rees Sears (March 1, 1913 – October 12, 2002) was a notable aeronautical engineer and educator.

Northrop aircraft
By role
USAAS/USAAC/USAAF/USAF bomber designations, Army/Air Force and Tri-Service systems
Original sequences
Main sequence
Long-range Bomber
Tri-Service sequence


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