Boeing XB-56
The Boeing B-56 was a proposal from Boeing for a re-engineered version of the jet-powered B-47 Stratojet bomber aircraft . The original name for this modification was YB-47C. The designation XB-56 was later used for the project and the planned test vehicle.
| Boeing XB-56 | |
|---|---|
 Drawing of the XB-56 project |
|
| Type: | Strategic bomber |
| Design country: | |
| Manufacturer: | |
| Number of pieces: |
0 (1 B-47 not converted) |
development
The B-47 was equipped with six J-47 turbojet engines, each with a thrust of 23 kN. The engines were mounted in four nacelles, each with a pylon under the wing, with two engines in each inner nacelle and one engine in each outer nacelle. In order to reduce the complexity and to increase the flexibility when changing the engine, it was proposed to choose a motor with higher thrust so that a motor could be mounted in each of the 4 nacelles.
The Allison J35 turbojet engine was developed in the late 1940s and delivered 38 kN or 9,700 lbf (43 kN with afterburner ) of thrust . Thus, 4 × 8,500 lbf = 34,000 lbf (150 kN) of thrust would be provided using this motor, compared to 6 × 5,200 lbf = 31,200 lbf (139 kN) used in the standard production B-47. The conversion to the B-56 became easier, simpler and more powerful.
In January 1950, the contract was signed with Boeing, in which the conversion of an aircraft was decided. A B-47B-20-BW (s / n 50-082) was provided for the conversion. The date for the first flight was set for April 1951.
A combination of delays and less than expected thrust from the J35 led to other engines being considered. The Allison J71 was proposed, but problems with this engine meant it was not available on the now renamed B-56A. The Pratt & Whitney J57 , which eventually produced 76,000 kN of thrust, was also considered, but this engine was still in development, and the Boeing B-52 Stratofortress, which was being developed at the same time (first flight was April 1952), had priority for equipping with these engines.
The B-56 program was canceled in December 1952 before the prototype conversion began. The unconverted B-47 was then used as an instruction and training cell for the ground crews and was deployed in the late 1960s at the Naval Air Facility El Centro as an exit / evacuation trainer for crews and on-call personnel.
Technical specifications
| Parameter | Data of the XB-56 |
|---|---|
| crew | 3 |
| length | 33.64 m |
| span | 35.36 m |
| height | 8.30 m |
| Wing area | 132.66 m² |
| Wing extension | 9.43 |
| Engines | 4 × Allison-J71 -A-5 turbojet jet engines |
Armament
- Pipe armament for self-defense
- 1 × rear stand unit with a double mount in a rotating dome with 2 × 20 mm M24A1 automatic cannons with 400 rounds of ammunition each. The stern stand unit is remotely controlled from the cabin by a crew member. Fire control radar AN / APG-39 as target aid.
- Explosive ordnance up to 11,000 kg in the internal bomb bay
- Unguided bombs
- 1 × B53 (free fall bomb with nuclear 9-MT explosive device)
- 1 × B41 (free-fall bomb with nuclear 25-MT explosive device)
- 2 × Mk.15 (free-fall bomb with thermonuclear 3.8 MT explosive device)
- 28 × Mark 82 LDGP (227 kg / 500 lb free fall bomb)
variants
- XB-56
- Designation for a single B-47, which was newly motorized with four YJ71-A-5 engines, later re-designated as YB-56 and YB-47C , but not implemented.
- B-56
- Designation for a production variant of the bomber version, canceled and not built.
- RB-56A
- Designation for a production variant of the reconnaissance version analogous to the RB-47, canceled and not built.
Self defense
- Active measures
- 1 × decoys launcher with heat flare decoys
- 1 × electronic jammer AN / APT-5
- Passive action
- AN / APS-54 radar warning sensor
literature
- Erik Simonsen: Project Terminated . Crécy Publishing, Manchester 2013, ISBN 978-0-85979-173-1 .
Web links
Individual evidence
- ↑ a b Jones, Lloyd S .: US Bombers: B1-B70. Aero Publishers, Inc., 1969, LCCN 62-15969.
- ↑ National Museum fact sheet Boeing B-56A ( Memento of the original from October 26, 2014 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b c Andrade 1979, p. 56.
