Engine: Six General Electric YJ93's of 30m000 lbs. Thrust each w/afterburner. Top Speed: 2,000 mph. Span: 105 ft. 0 in. Range: Over 4,000 miles. Length: 192 ft. 2 in. q/boom. Ceiling: Above 70,000 ft. Height: 30 ft. 9 in. XB-70 world's most exotic aircraft, was designed in the 1950's as high-altitude bomber flying three times the speed of sound. Due to limited funds, only two built as reserch aircraft to study aerodynamics, propulsion, and other aspects of large supersonic aircraft. Surviving XB-70 was retired to AF museum, W-PAFB, Ohio, in 1969.