Martin XB-48: Difference between revisions
→Specifications (XB-48): format, precision |
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|empty weight alt= 26,535 kg |
|empty weight alt= 26,535 kg |
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|loaded weight main= 92,600 lb |
|loaded weight main= 92,600 lb |
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|loaded weight alt= 42, |
|loaded weight alt= 42,000 kg |
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|useful load main= |
|useful load main= |
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|useful load alt= |
|useful load alt= |
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|max takeoff weight main= 102,600 lb |
|max takeoff weight main= 102,600 lb |
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|max takeoff weight alt= 46, |
|max takeoff weight alt= 46,540 kg |
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|more general= |
|more general= |
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|engine (jet)= [[General Electric J35]] |
|engine (jet)= [[General Electric J35]] |
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|power alt= kW |
|power alt= kW |
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|power original= |
|power original= |
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|max speed main= 454 kn |
|max speed main= 454 kn |
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|max speed alt= |
|max speed alt= 523 mph, 841 km/h |
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|max speed more=at 35,000 ft |
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|cruise speed |
|cruise speed main= 361 kn |
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|cruise speed alt= 415 mph, 668 km/h |
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|never exceed speed main= |
|never exceed speed main= |
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|never exceed speed alt= |
|never exceed speed alt= |
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Revision as of 15:13, 17 September 2009
| XB-48 | |
|---|---|
| |
| Role | Bomber |
| Manufacturer | Glenn L. Martin Company |
| First flight | 1947-06-22 |
| Status | Cancelled in 1948 |
| Number built | 2 |
The Martin XB-48 was a medium jet bomber developed in the mid-1940s. It never saw production or active duty, and only two prototypes, serial numbers 45-59585 and 45-59586[1], were built.
In 1944 the U.S. War Department was aware of aviation advances in Germany and issued a requirement for a range of designs for medium bombers weighing from 80,000 lb (36,287 kg) to more than 200,000 lb (90,718 kg). Other designs resulting from this competition, sometimes named the class of '45, included the North American XB-45 and the Convair XB-46. Production orders finally went to the B-45 Tornado and even this airplane only served for a couple of years before again being replaced by the much more modern B-47 Stratojet.
In retrospect, the class of '45 were transitional aircraft combining the power of turbojets with the aeronautical knowledge of World War II. The XB-48 was no exception, as its round fuselage and unswept wings show a distinct patronage from the earlier Martin B-26 medium bomber. Still, where the B-26 had enough thrust with two massive 18-cylinder radial engines, the XB-48 needed no less than six of the new jet engines. Although the pictures make it look like the aircraft has three engine gondolas under each wing, the jet engines were actually clustered in two flat three-engined gondolas with an intricate system of air canals between the engines providing cooling. At the time of the XB-48's design, jet propulsion was clearly still in its infancy.
The XB-48 was the first aircraft designed with bicycle type landing gear. The wing airfoil was too thin to house conventional land gear mechanisms.[2] The main landing gear was in the fuselage and small outriggers located on each wing were used to balance the aircraft.
The XB-48 made its first flight on 22 June 1947, a 37-minute, 73 mi (117 km) hop from Martin's Baltimore, Maryland plant to NAS Patuxent River, Maryland, but blew all four tires on its fore-and-aft mounted undercarriage on landing when pilot Pat Tibbs applied heavy pressure to the specially-designed, but very slow to respond, insensitive air-braking lever. Tibbs and co-pilot Dutch Gelvin were uninjured. [3]
Specifications (XB-48)
Data from "Encyclopedia of US Air Force Aircraft and Missile Systems, Volume II" by Knaack, Marcelle Size (Washington: Office of Air Force History, ISBN 0-16-002260-6), 1988.
General characteristics
- Crew: 3 (pilot, co-pilot, and bomber-navigator)
Performance
Armament
- Guns: 2 × .50 in (12.7 mm) M7 machine guns in tail turret (proposed)[2]
- Bombs: 1 × 20,000 lb (9,980 kg) or 36 × 250 lb (113 kg)
See also
Aircraft of comparable role, configuration, and era
Related lists
References
Notes
- ^ http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2661
- ^ a b Jones, Lloyd S.: U.S. Bombers: B-1 - B-70, Aero Publishers, Inc., 1969. LCCN 62-15969
- ^ Mizrahi, Joe, "The Last Great Bomber Fly Off", Wings, Granada Hills, California, June 1999, Volume 29, Number 3, pages 50-52.
Bibliography
- Jones, Lloyd S. U.S. Bombers, B-1 1928 to B-1 1980s. Fallbrook, CA: Aero Publishers, 1962, second edition 1974. ISBN 0-8168-9126-5.