Oblique wing: a single full-span wing pivots about its midpoint, as used on the NASA AD-1, so that one side sweeps back and the other side sweeps forward. Telescoping wing: the outer section of wing telescopes over or within the inner section of wing, varying span, aspect ratio and wing area, as used on the FS-29 TF glider.[27] Detachable wing. The WS110A study proposed a long wing for subsonic takeoff and cruise, which then detached the outer panels to drop away, leaving a short-span wing for supersonic flight.