Photos: Amazing X-Planes from the X-1 to XV-15

Rotor Systems Research Aircraft/X-Wing

NASA

The Rotor Systems Research Aircraft/X-Wing, a vehicle that was used to demonstrate an advanced rotor/fixed wing concept called X-Wing, is shown here on Nov. 4, 1986. The vehicle was rolled out in 1986 and made several taxi tests before the program was terminated in 1988.

XB-70 Valkyrie

NASA

The XB-70A, capable of flying three times the speed of sound, was the world's largest experimental aircraft in the 1960s. The plane was built to test stability and handling of large delta-wing aircraft at high speeds.

Republic XF-91 Thunderceptor

NASA

The Republic XF-91 Thunderceptor, created as a Prototype fighter, sits at the South Base ramp at Edwards Air Force Base. The image was taken in March 1951.

XF-92A

NACA/NASA

This photograph of the XF-92A was taken at Edwards Air Force Base in January 1953. The plane was designed as the prototype of a delta-wing fighter. A brief series of 25 flights were made in 1953 which showed the aircraft had violent pitch-up tendencies during turns.

XV-15 Tilt Rotor

NASA

This photo shows the unique XV-15 Tiltrotor aircraft in vertical flight at the NASA Dryden Flight Research Center. The aircraft was involved in limited research in 1980 and 1981 in order to improve design and efficiency of rotorcraft using tilt rotors. The image was taken on Oct. 3, 1980.

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