XB-70 Valkyrie
The XB-70 Larger version
Description
Role	Bomber prototype
Crew
Dimensions
Length	185 ft 10 in	56.6 m
(with boom)	192 ft 2 in	58.6 m
Wingspan	105 ft	32 m
Height	30 ft 9 in	9.4 m
Wing area
Weights
Empty
Loaded	534,700 lb	243 t
Maximum take-off
Powerplant
Engines	6 GE YJ-93
Power
Performance
Maximum speed	2,056 mi/h at 73,000 ft	3300 km/h at 22250 m
Operating range	4,288 mi	7900 km
Service ceiling	77,350 ft	23600 m
Rate of climb
Armament
N/A

The North American XB-70 "Valkyrie" was conceived for the Strategic Air Command in the 1950s as a high-altitude bomber that could fly three times the speed of sound (Mach 3). Because of funding limitations, only two were built, not as bombers, but as research aircraft for the advanced study of aerodynamics, propulsion, and other subjects related to large supersonic aircraft. The Valkyrie was built largely of stainless-steel honeycomb sandwich panels and titanium. It was designed to make use of a phenomenon called "compression lift," achieved when the shock wave generated by the airplane flying at supersonic speeds supports part of the airplane's weight. For improved stability at supersonic speeds, the Valkyrie could droop its wingtips as much as 65 degrees.

The first XB-70 made its maiden flight on September 21, 1964. The second airplane first flew on July 17, 1965, but on June 8, 1966, it crashed following a mid-air collision during a photo op performance. The first plane continued its research program until February 4, 1969 when it was flown to the U.S. Air Force Museum.

Specifications

• Span: 105 ft (32 m)
• Length: 185 ft 10 in (56.6 m) without boom; 192 ft 2 in (58.6 m) with boom
• Height: 30 ft 9 in (9.4 m)
• Weight: 534,700 lb (243 t) loaded
• Armament: None
• Engines: 6 GE YJ-93s developing 30,000 lb (133 kN) thrust each with afterburner.