scanzen, from nationalmuseum.af.mil:
General Dynamics F-111A Aardvark. The F-111A could change the angle or “sweep” of its wings in flight. This image shows three different wing positions. With the wings swept forward, the F-111A had more lift to carry heavier loads, and it could land or take off at a slower speed. With the wings swept back, the F-111A could fly at very high speeds.