F-16XL | |
---|---|
F-16XL in flight | |
Role | Experimental fighter |
Manufacturer | General Dynamics |
First flight | 3 July 1982 |
Primary users |
United States Air Force NASA |
Number built | 2 |
Developed from | General Dynamics F-16 Fighting Falcon |
The General Dynamics F-16XL is a derivative of the F-16 Fighting Falcon, with a cranked-arrow delta wing. It was originally conceived as a technology demonstrator, later entered in the United States Air Force's (USAF) Enhanced Tactical Fighter (ETF) competition but lost to the F-15E Strike Eagle. Several years after the prototypes were shelved, they were turned over to NASA for additional aeronautical research. Both aircraft are currently stored at Edwards AFB.
In 1977, the F-16XL started out as the F-16 SCAMP (Supersonic Cruise and Maneuver Prototype) at General Dynamics Fort Worth. Under the leadership of Harry Hillaker (father of the original F-16), the original goal of the program was to be a quick project to demonstrate the applicability of supersonic transport technologies to military aircraft. The big wing generated a lot of lift, and typical aerodynamic limitations of delta wings were overcome by the F-16's relaxed static stability. The F-16's electronic flight control system was tweaked to allow control at high angles of attack. The wing was also a big fuel tank which greatly boosted range. The study went on for two years. The goal of the cranked arrow was to have a high sweep inboard panel for low drag at supersonic speeds, and a low sweep outboard panel to provide better handling and maneuverability at subsonic speeds.
Working closely with NASA's Langley Research Center, the company invested significant Internal Research and Development (IRAD) funds for wind tunnel testing and that led to the Model 400. It featured all moving wing tips for roll control and an all moving vertical tail. These surfaces were actually the horizontal tail surfaces from the F-16A. These surfaces were later dropped as they did not provide adequate control at low speed, high angle of attack. Also, there would have been no provision for wing-tip mounted missiles. The main wing incorporated forebody strakes to enhance vortex generation for high angle of attack maneuverability, negative stability for improved subsonic lift and reduced supersonic drag. It was built around a 40-inch fuselage stretch. Both the large wing and fuselage stretch yielded a dramatic increase in range at all speeds. In 1979, with a strong positive response by the USAF, GD released the Model 400 for a company funded preliminary design effort.