The X-53 Active Aero Elastic Wing development program is a completed American research project that was undertaken jointly by the Air Force Research Laboratory, Boeing Phantom Works and NASA’s Dryden Flight Research Centre, where the technology was flight tested on a modified McDonnell Douglas F/A-18 Hornet.
Active Aeroelastic Wing Technology is a technology that integrates wing aerodynamics, controls, and structure to harness and control wing aero elastic twist at high speeds and dynamic pressures.
By using multiple leading and trailing edge controls like “aerodynamic tabs”, subtle amounts of aero elastic twist can be controlled to provide large amounts of wing control power, while minimizing manoeuvre air loads at high wing strain conditions or aerodynamic drag at low wing strain conditions. This program was the first full-scale proof of AAW technology.
To test the AAW theory, NASA and the USAF agreed to fund development of a single demonstrator, based on the F/A-18. Work started by taking an existing F/A-18 airframe modified with a preproduction wing, and added an outboard leading edge flap drive system and an updated flight control computer.
Active aero elastic wing control laws were developed to flex the wing, and flight instrumentation was used to accurately measure the aero elastic performance of the wing plan form.
Flight software was then modified for flight testing, and the aircraft first flew in modified form on November 15, 2002.
The aircraft successfully proved the viability of the concept in full scale during roll manoeuvre testing in 2004–2005.
The test aircraft was re-designated X-53 on August 16, 2006.
38 ft 5 in (11.71 m)
15 ft 3 in (4.65 m)
Max take-off weight
39,000 lb (17,690 kg)
2 × General Electric F404-GE-400 low-bypass turbofan engines, 16,000 lbf (71 kN) thrust each
1,188 mph (1,912 km/h, 1,032 kn)
50,000 ft (15,000 m)
The leading edge flap drive system was modified at McDonnell Douglas using an outboard actuation unit developed by Moog Inc.
AAW flight control laws were programmed into a research flight control computer modified to include independently actuated outboard leading edge control surfaces.