Martin XB-51
XB-51 | |
---|---|
First prototype, 46-685 during testing | |
Role | Bomber |
Manufacturer | Glenn L. Martin Company |
First flight | 28 October 1949 |
Retired | 25 March 1956 |
Status | Canceled in 1952 |
Primary user | United States Air Force |
Number built | 2 |
The Martin XB-51 was an American
Design and development
This unorthodox design, first flying on 28 October 1949, was fitted with three
The main landing gear consisted of dual wheel sets in tandem in the fuselage, similar to the Boeing B-47 Stratojet, with outrigger wheels at the wingtips (originally proved on a modified Martin B-26 Marauder named "Middle River Stump Jumper"[1]). The XB-51 was a large but aerodynamically "clean" design which incorporated nearly all major systems internally.[3] The aircraft was fitted with a rotating bomb bay, a Martin trademark; bombs could also be carried externally up to a maximum load of 10,400 lb (4,700 kg), although the specified basic mission required only a 4,000 lb (1,814 kg) bombload.[4] Eight 20 mm cannon mounted in the nose would have been installed in production aircraft.[3]
Crew was a pilot under a "fighter"-type bubble canopy and a Short-range navigation and bombing system (SHORAN) operator/navigator in a compartment located lower than and to the rear of the cockpit (only a small observation window was provided).[3] Both crew members were provided with a pressurized, air conditioned environment, equipped with upward-firing ejection seats.[3] The XB-51 was the first Martin aircraft equipped with ejection seats, these being of their own design.[5]
Operational history
In 1950, the
Test flights showed the XB-51 to be highly maneuverable at low altitudes and substantially faster than the Canberra and faster than most fighter aircraft of the era.
While the XB-51 was not selected for procurement, it was decided that Martin would build 250 Canberras under license, under the designation B-57. Furthermore, Martin's rotating bomb bay would be incorporated into production variants of the B-57. A "Super Canberra", incorporating other XB-51 features, such as swept wings and tail-planes, was also proposed. This aircraft – although it promised much better speed and performance than the B-57 – never reached the prototype stage, mainly because the many changes would have taken too long to implement and test, before it could be put into production.[1]
Flights by the XB-51 prototype, 46-685, continued, for general research purposes, following the project's official cancellation by the USAF. A second prototype, 46-686, which first flew in 1950, crashed during low-level aerobatics on 9 May 1952, killing pilot Major Neil H. Lathrop. 46-685 continued to fly, including an appearance in the film Toward the Unknown as the "Gilbert XF-120" fighter.[note 1] The surviving prototype was en-route to Eglin AFB to shoot additional footage when it crashed during takeoff, following a refueling stop in El Paso, Texas, on 25 March 1956.[3]
Specifications (XB-51)
Data from U.S. Standard Aircraft Characteristics[6]
General characteristics
- Crew: 2
- Length: 85 ft 1 in (25.93 m)
- Wingspan: 53 ft 1 in (16.18 m)
- Height: 17 ft 4 in (5.28 m)
- Wing area: 548 sq ft (50.9 m2)
- Airfoil: NACA 63A010[7]
- Empty weight: 30,906 lb (14,019 kg)
- Gross weight: 57,874 lb (26,251 kg)
- Max takeoff weight: 62,452 lb (28,328 kg)
- Powerplant: 3 × General Electric J47-GE-13 turbojetengines, 5,200 lbf (23 kN) thrust each
Performance
- Maximum speed: 644 mph (1,036 km/h, 560 kn)
- Range: 1,075 mi (1,730 km, 934 nmi)
- Ferry range: 1,444 mi (2,324 km, 1,255 nmi)
- Service ceiling: 41,750 ft (12,730 m)
- Rate of climb: 6,600 ft/min (34 m/s)
- Wing loading: 105.6 lb/sq ft (516 kg/m2)
- Thrust/weight: 0.27
Armament
- Guns: 8 × 20 mm M24 cannon (0.79 in) cannon with 1,280 rounds
- Rockets: 8 × High Velocity Aerial Rockets (HVAR) or
- Bombs: Up to 10,400 lb (4,720 kg) carried internally
See also
Aircraft of comparable role, configuration, and era
- Douglas A3D Skywarrior
- Douglas B-66 Destroyer
- English Electric Canberra
- Sud Aviation Vautour
- Ilyushin Il-28
- Yakovlev Yak-25
- Yakovlev Yak-28
Related lists
- List of attack aircraft
- List of bomber aircraft
- List of military aircraft of the United States
References
Notes
- ^ A few seconds of test flight footage of an XB-51 also appeared in the 1951 Tales of Tomorrow episode "Plague From Space". Note: Although the XB-51 did not receive an official name, "Panther" had been suggested by the company.
- ^ a b c d Winchester 2005, p. 144.
- ISBN 0-942612-00-0, p.5
- ^ a b c d e f g Winchester 2005, p. 145.
- ^ "Pivoting Bomb-bay Door Permits Accurate Drops at High-Speeds." Popular Mechanics, February 1954, p. 126.
- ISBN 0-7603-1185-4.
- ^ "Standard Aircraft Characteristics: XB-51" (PDF). US Air Force. 11 July 1952. Archived from the original (PDF) on 13 March 2016. Retrieved 8 June 2017.
- ^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.
Bibliography
- Andrade, John M. U.S. Military Aircraft Designations and Serials since 1909. Earl Shilton, Leicester, UK: Midland Counties Publications, 1979. ISBN 0-904597-22-9.
- Boyne, Walter. "Attack, The Story of the XB-51, Martin's Phantom Strike Ship!" Airpower, Volume 8, No. 4, July 1978.
- Jones, Lloyd S. U.S. Bombers, B-1 1928 to B-1 1980s. Fallbrook, California: Aero Publishers, 1962, second edition 1974. ISBN 0-8168-9126-5.
- Mikesh, Robert C. 'B-57 Canberra At War 1964-1972. London: Ian Allan, 1980. ISBN 0-7110-1004-8.
- Winchester, Jim. "Martin XB-51." Concept Aircraft: Prototypes, X-Planes and Experimental Aircraft. Kent, UK: Grange Books plc., 2005. ISBN 978-1-84013-809-2.