one or two
1 x 29,000 lbs.
1 - 20 mm
54 ft. 2 in.
34 ft. 3 in.
General Dynamics F-16XL
Two General Dynamics F-16XL aircraft were built to explore the ability of supersonic cruise without the use of an afterburner combined with acceptable maneuverability, takeoff and landing characteristics.
The unique "crank-arrow" wing allows for low supersonic wave drag plus excellent handling throughout the performance range.
The wings of the General Dynamics F-16 were replaced by the crank-arrow design with approximately 20% more total area than that of the standard aircraft.
Space-age light weight building materials helped keep the weight down, although, even with them, the F-16XL is nearly 3,000 lbs. heavier than the standard aircraft.
Other modifications included a 4.6 foot addition to the fuselage, removal of the ventral fins to improve ground clearance, and three degrees of positive incidence added to the tail section. Fuel load was up over 80%, maximum payload nearly doubled and range improved by 40%. A total of 27 hard points were on the aircraft.
The F-16XL had 11% less drag during sub-sonic flight and 25% less drag in supersonic flight than the standard aircraft. Low altitude flight at high speeds is said to be much smoother.
NASA had been using the General Dynamics F-16XL for testing the effects of boundary layer pressures, distribution and improving laminar air flow, while flying at supersonic speeds. The aircraft was equipped with strips of tubing along the wing edges for pressure test measurements.
Although a successful design, the USAF opted for more standard design aircraft over the General Dynamics F-16XL to save expenses.