Northrop YB-49
YB-49 | |
---|---|
YB-49 | |
Role | Strategic bomber |
National origin | United States |
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 |
Developed from | Northrop YB-35 |
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
Design and development
This section needs additional citations for verification. (December 2022) |
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 June 5, 1948, killing its pilot, Major Daniel Forbes (for whom
During flight tests in the 1940s, it was noticed that the aircraft had a small
On 9 February 1949, the first YB-49 flew from
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]
Bombing target tests showed a tendency of flying wings to "hunt" in
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
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, which were 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. Coincidentally, the sole remaining 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.
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.[7] 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.[8]
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.[9]
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."[10] 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.[11]
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
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.[citation needed] 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."[15] The new bomber would be publicly displayed for the first time in 1988.[16]
Notable appearances in media
Specifications (YB-49)
Data from National Museum of the United States Air Force,[9] and U.S. Standard Aircraft Characteristics[18][19]
General characteristics
- Crew: 6
- Length: 53 ft 1 in (16.18 m)
- Wingspan: 172 ft 0 in (52.43 m)
- Height: 15 ft 2 in (4.62 m)
- Wing area: 4,000 sq ft (370 m2)
- Aspect ratio: 7.2
- Airfoil: root: NACA 653-019; tip: NACA 653-018
- Empty weight: 88,442 lb (40,117 kg)
- Gross weight: 133,569 lb (60,586 kg)
- Max takeoff weight: 193,938 lb (87,969 kg)
- Powerplant: 8 × Allison J35-A-15 turbojetengines, 4,000 lbf (18 kN) thrust each
- (6 × 5,000 lbf (22 kN) Allison J35-A-19engines on YRB-49)
- (6 × 5,000 lbf (22 kN)
Performance
- Maximum speed: 493 mph (793 km/h, 428 kn)
- Cruise speed: 365 mph (587 km/h, 317 kn)
- Combat range: 4,000 mi (6,400 km, 3,500 nmi) Other sources say 2,806 [21] with 10,000 lb (4,536 kg) bombload, 365 Knots in 8:27 hours with 10,000 lbs of bombs.
- Service ceiling: 45,700 ft (13,900 m)
- Rate of climb: 3,785 ft/min (19.23 m/s)
- Wing loading: 33 lb/sq ft (160 kg/m2)
- Thrust/weight: 0.23
- Take-off run: 4850 ft[21]
- Take-off distance to 50 ft (15 m): 5850 ft [21]
Armament
- 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
- List of bomber aircraft
- List of flying wings
- List of military aircraft of the United States
References
Notes
- ^ a b c d e f Pattillo 2001, p. 185.
- ^ a b c d e Wooldridge, E.T. "The Northrop bombers." Century of Flight, 2003. Retrieved: 22 October 2010.
- ^ History Channel, 25 August 2004. Retrieved: 25 August 2012.
- ^ "B-49 - United States Nuclear Forces".
- ^ "Popular Science". September 1986.
- ^ Chong, Tony, 2016. Flying Wings & Radical Things: Northrop’s Secret Aerospace Projects & Concepts 1939-1994. Forest Lake, Minnesota: Specialty Press.
- ^ Pattillo 2001, p. 186.
- ^ Honey, John. "The Wing Will Fly." Broadcast on The Discovery Channel: 1991.
- ^ a b "Fact sheet: Northrop YRB-49A." National Museum of the United States Air Force. Retrieved: 29 October 2010.
- ^ Fitzsimons 1978, p. 2282.
- ^ Pattillo 2001, p. 153.
- ^ Donald 1997, p. 709.
- ^ Donald 1997, p. 708.
- ^ Jones 1975, p. 238.
- ^ Withington and Davey 2006, p. 12.
- ^ Withington and Davey 2006, p. 13.
- ^ Howe, Tom. "Northrop YB-49 Flying Wing." cedmagic.com. Retrieved: 25 August 2012.
- ^ "Standard Aircraft Characteristics: YB-49 Flying Wing" (PDF). US Air Force. 20 December 1949. Retrieved 2 November 2016.
- ^ Northrop YB-49 Flying Wing Bomber page 14
- ^ "Northrop YB-49".
- ^ a b c Post World War II Bombers by Marcelle Size Knaack, page 545
Bibliography
- 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.
- Pelletier, Alain J. "Towards the Ideal Aircraft: The Life and Times of the Flying Wing, Part Two". ISSN 0143-5450.
- 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.