Boeing X-53 Active Aeroelastic Wing

The X-53 Active Aeroelastic Wing (AAW) was an American research project undertaken jointly by the Air Force Research Laboratory, Boeing Phantom Works and NASA's Dryden Flight Research Center, where the technology was flight tested on a modified McDonnell Douglas F/A-18 Hornet. Active aeroelastic wing technology integrates wing aerodynamics, controls and structure to harness and control aeroelastic twist at high speeds and dynamic pressures, using multiple leading and trailing edge controls so that subtle twist gives large wing control power while minimising manoeuvre loads or drag. It was the first full-scale proof of the technology. The concept began with wind tunnel testing in the mid-1980s under Air Force contract, and the designation X-52 was skipped to avoid confusion with the B-52. A pre-production F/A-18 was chosen for its relatively high wing aspect ratio for a fighter.