The Ames-Dryden (AD)-1 was an experimental aircraft developed by NASA during the 1970s. Its wing could pivot up to 60° to present the most efficient angle for a given flight objective:
The oblique wing was the brainchild of NASA aeronautical engineer Robert T. Jones, whose analytical and wind tunnel studies at the NASA Ames Research Center, Moffet Field, California, indicated that an oblique wing, supersonic transport might achieve twice the fuel economy of an aircraft sporting more conventional wings.[...]
The oblique wing on the AD-1 pivoted about the fuselage, remaining perpendicular to it during slow flight and swinging to angles of up to 60 degrees as aircraft speed increased.
The swing wing concept was first evaluated by a small, propeller-driven, remotely-piloted research vehicle (RPRV) flown at Dryden in 1976. These early techniques for gathering data about the oblique wing aircraft were applied to the twin turbojet, piloted AD-1, which was flown from 1979 to 1982.
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