Northrop YB-49
| Northrop YB-49 | |
|---|---|
 YB-49 during a test flight |
|
| Type: | Prototype of a strategic bomber |
| Design country: | |
| Manufacturer: | |
| First flight: |
October 21, 1947 |
| Commissioning: |
Flight tests ended in 1950 |
| Production time: |
Was never mass-produced |
| Number of pieces: |
2 + 1 six-beam YRB-49A |
The Northrop YB-49 was a prototype of a turbine-powered flying wing - Bombers with eight jet engines that shortly after the Second World War for the US Air Force has been developed. It was an unchanged conversion of the Northrop YB-35 with jet propulsion instead of propeller propulsion. The bomber was never built in series, instead the conventionally built Convair B-36 was preferred. The Northrop Corporation gained experience with the flying wing at an early stage, which proved to be valuable during the construction of the Northrop B-2A Spirit , among other things .
history
The first YB-49 flew on October 1, 1947 and immediately delivered better results than the YB-35 had ever achieved. It set unofficial records for the longest time at high altitude (6 hours over 40,000 feet / 12,200 meters) and the fastest transcontinental flight. It took 4 hours 20 minutes from California to Andrews Air Force Base in Washington DC .
The program, like that of the YB-35, suffered from serious problems, culminating in the crash of the first prototype 42-102367 in California on June 5, 1948. The entire crew was killed, including Capt. Glen Edwards , the test pilot responsible for controllability and stability, after whom Edwards Air Force Base near Los Angeles was named. This air force base was previously called Muroc AFB and was the airfield from which the YB-49 began its record-breaking transcontinental flight. The cause of the crash was never known; structural stability problems are believed to have caused the aircraft to break apart after a stall and free fall test in midair.
Other problems also came from converting the propeller plane into a jet; The only problem was that the landing gear retracted much too slowly, which was compensated by test pilots by climbing steeper than intended after take-off so as not to go too fast, in order to avoid damaging the landing gear flaps by the airstream.
In September 1948, the US Air Force wanted to turn the YB-49 into the RB-49A , a reconnaissance aircraft , and placed the order for mass production with Consolidated Vultee Aircraft Corporation . In January 1949, however, this order was stopped after the Air Force test pilot Major Robert Cardenas described the aircraft as unstable. It was also he who advised the other test pilots not to perform stall maneuvers because the control surfaces were ineffective.
Aerodynamicists now suspect that this instability, which already existed to a lesser extent in the YB-35, was due to the fact that the YB-49 was fitted with jet engines instead of the original propeller engines without changing the wing.
The tests with the second prototype 42-102368 lasted until March 15, 1950 and kept showing new problems that would make the aircraft almost unsuitable as a bomber. Due to the design as a flying wing and the flight control systems for automatic stabilization that were not yet available at the time, the YB-49 suffered from poor pitch stability (around the transverse axis), which had a significant negative impact on aiming with the optical sighting device "Norden" when used as a bomber. There was also a serious engine fire, which the aircraft survived. Only shortly after the program was canceled, the YB-49 had an accident while rolling on the ground and burned out completely.
End of program
There have been longstanding conspiracy theories about the lifting of the Flying Wing program. Specifically, an allegation by Jack Northrop that Air Force Secretary Stuart Symington tried to force him to merge his company with Atlas Corporation-controlled Convair. In a recorded 1979 interview, Jack Northrop claimed that the Flying Wing contract had been terminated. He did not want to agree to the planned merger because, from his point of view, the merger claims were “grossly unfair”. When Northrop refused, Symington allegedly canceled the B-35 and B-49 programs. Symington, in turn, became President of Convair after he had left government service a short time later. [16]
Other observers note that the YB-35 and YB-49 designs had well-documented performance and design issues, while the Convair B-36 needed more development funding. At that point it appeared that both the B-36 and B-35 programs could be canceled. The USAF and the Texas Congressional delegation wanted a production program for the large aircraft manufacturing plant in Fort Worth, and Convair had much more effective lobbyists in Washington DC. Northrop Corporation has always been a technological pioneer, but Jack Northrop's independence often clashed with Washington's political wheeling-and-dealing, which tended to make huge military allocations.
As a result, the B-36 prevailed with just over 380 aircraft built. Earlier that year, when the YB-49 jet bomber was canceled, Northrop received a smaller production contract for its F-89 Scorpion fighter in compensation for the lost Flying Wing contract.
Technical data (YB-49)
General data
- Crew: 7
- Length: 16.20 m
- Wingspan : 52.40 m
- Height: 6.2 m
- Wing area: 372 m²
- Empty weight: 40,100 kg
- Loaded mass: 60,600 kg
- Max. Takeoff mass: 88,000 kg
- Engines: 8 × Allison J35-A-15 turbo jets with 17 kN thrust each
power
- Top speed: 789 km / h
- Combat range: 2600 km
- Transfer range: 5700 km
- Service ceiling : 13,900 m
- Climb rate: 1145 m / min
- Thrust-to-weight ratio: 2.2 N / kg
Armament
- 4 × machine guns caliber 12.7 mm
- 14,500 kg bombs
Others
The US feature film Battle of the Worlds , released in 1953, contains original footage of the launch of a YB-49 to depict an atomic bomb attack against alien invaders. A YB-49 also plays a crucial role in Clive Cussler's novel Brennendes Wasser (Curt Austin / Numa Files).
See also
Web links
- Weekly report on the first flight on October 23, 1947 (approx. 4.20 min.)
- Are any of Northrop's “flying wings” from the 1940s still around? airspacemag.com
Individual evidence
- ^ Northrop YRB-49A Smithsonian
- ^ A b c d Philip Kaplan: Big Wings: The Largest Airplanes Ever Built , Pen and Sword 2005, ISBN 978-1-84415-178-3 , pages 66-68
- ↑ David Doyle: Flying WIngs - a visual hostory of the Northrop XB-35 & YB-49 flying wings . Ed .: HobbyLink. Ampersand Publishing Group, 2015, ISBN 978-0-9895547-7-0 , pp. 120 .
- ↑ Jim Winchester, "Northrop XB-35 / YB-49". Concept Aircraft: Prototypes, X-Planes and Experimental Aircraft . Ed .: Grange Books plc. Kent, UK 2005, ISBN 978-1-84013-809-2 .