Robert T. Jones of Ames calculated that an aircraft’s wing made to pivot 4 degrees to the fuselage might halve the fuel consumption. Specifications bases, in particular geometric configuration were established by NASA based on one made by Boeing. In consultation with the Rutan Aircraft Factory, Ames and Dryden built the AD-1 oblique wing aircraft in 1977, a twin jet composite aircraft with direct controls and a top speed of 175kts (324kph). Set perpendicular to the fuselage for takeoff and landing, the oblique wing could be made to rotate up to 60 degrees for higher speed flight and between 1979 and 1982, demonstrated the feasibility of such a concept, performing three landings with the wings pivoted at 45 degrees.
The test aircraft's 32‑foot wing can be pivoted 60 degrees during cruise, to reduce drag while still allowing high airspeeds. In the conventional position, the wing should provide ample lift and stability for takeoffs, landings and low‑speed manoeuvres. Designated the AD‑1, the test aircraft is 40 feet long, has a gross weight of 2,000 pounds and is powered by two 220‑pound‑thrust turbojets. The structure was made entirely of fiberglass.
The aircraft was delivered by Aimes at Dryden Flight Research Center at Edwards Air Force Base in March 1979. The first flight was performed by test pilot NASA Thomas C. McMurtry December 21, 1979. Thomas flew only the 79 flights until 7 August 1982.
Although the oblique wing is still considered by some as a viable concept for large transport, unpleasant flight characteristics of the AD-1 at certain angles discouraged designers to adopt this configuration.
Wing span: 9.85 m
Length: 11.82 m
Wing area: 8.60 m²
Aspect ratio: 11.2
Loaded weight: 809 kg
Empty weight: 535 kg
Max speed: 220 knts
Min speed: 74 knts