XB-70A Valkyrie Research Aircraft

XB-70A ValkyrieThe XB-70A, built by North American Aviation's Los Angeles (Calif.) Division for the U.S. Air Force, was an experimental high-speed, delta-wing aircraft designed to fly at three times the speed of sound and at altitudes in excess of 70,000 feet.

It was powered by six General Electric J-93 turbojet engines, each producing approximately 30,000 pounds of thrust. Primary purpose of the aircraft was to investigate the feasibility of long-range, high-speed flight and to advance the aeronautical state of the art in those areas.

Among its design features were a movable canard, the "compression lift" aerodynamic design principle, in-flight accessibility to electronics equipment, a shirt-sleeve environment for the crew, and encapsulated seats for crew ejection at speeds up to Mach 3 and at altitudes to above 70,000 feet.

An air-intake control system, necessarily different from conventional systems because of the high speed, sensed small changes in pressure during the XB-70's flight and adjusted accordingly, reducing the force of the supersonic speed at the intake duct to subsonic speed at the face of the engines.

A rugged landing gear, weighing more than six tons and consisting of two tons of wheels, tires and brakes, supported the XB-70 on the ground. Each main gear had four wheels and the nose gear two. In a single stop, the XB-70 absorbed kinetic energy equivalent to that used in stopping 800 medium-size automobiles from a speed of about 100 miles an hour.

First flight: Sept. 21, 1964
Span: 105 feet
Length: 185 feet
Height: 30 feet
Weight: Over 450,000 pounds
Engines: Six General Electric J-93 turbojets; 30,000-pound thrust class
Speed: 2,000 mph
Range: Intercontinental
Altitude: 70,000 feet, plus
Crew: Pilot, co-pilot
Fuel: JP-6