North American XB-70A Valkyrie

Wallpaper Description:

The North American Aviation XB-70 Valkyrie was the prototype of the B-70 nuclear-armed, deep-penetration strategic bomber for the Strategic Air Command of the U.S. Air Force.

In the 1950's, the North American Aviation company designed the Valkyrie bomber as a large, six-engine aircraft capable of reaching Mach 3+ while flying at 70,000 feet (21,000 m), which velocity and altitude capabilities would allow the evasion of interceptor aircraft, then the only effective weapon against bomber aircraft.

In 1961, improved, high-altitude surface-to-air missiles (SAMs), the U.S. Air Force's doctrinal change to low-level penetration bombing, the large development costs of the B-70 program, and the introduction of intercontinental ballistic missiles (ICBMs) to the U.S. nuclear arsenal, led to the cancellation of the B-70 program.

As such, two prototype aircraft were built, and designated XB-70A; these aircraft were used for supersonic test-flights during 1964–69.

In 1966, one prototype crashed after colliding in midair with a smaller jet aircraft; the remaining Valkyrie bomber is in the National Museum of the United States Air Force, in Ohio.

General characteristics

• Crew: 2
• Length: 189 ft 0 in (57.6 m)
• Wingspan: 105 ft 0 in (32 m)
• Height: 30 ft 0 in (9.1 m)
• Wing area: 6,297 ft² (585 m²)
• Air-foil: Hexagonal; 0.30 Hex modified root, 0.70 Hex modified tip
• Empty weight: 253,600 lb (115,030 kg; operating empty weight)
• Loaded weight: 534,700 lb (242,500 kg)
• Max. take off weight: 542,000 lb (246,000 kg)
• Power plant: 6 × General Electric YJ93-GE-3 afterburning turbojet
• Dry thrust: 19,900 lbf[73] (84 kN) each
• Thrust with afterburner: 28,800 lbf[74] (128 kN) each
• Internal fuel capacity: 300,000 lb (136,100 kg) or 46,745 US gallons (177,000 L)

Performance

• Maximum speed: Mach 3.1 (2,056 mph, 3,309 km/h)
• Cruise speed: Mach 3.0 (2,000 mph, 3,200 km/h)
• Range: 3,725 nmi (4,288 mi, 6,900 km) on combat mission
• Service ceiling: 77,350 ft (23,600 m)
• Wing loading: 84.93 lb/ft² (414.7 kg/m²)
• lift-to-drag: about 6 at Mach 2[107]
• Thrust/weight: 0.314