The F-16XL was a superlative aircraft that, unfortunately, never got the shot it deserved.
Did you know that two prototypes of a highly modified F-16 variant, known as the “F-16XL,” were developed and tested? It’s true. In the early 1980s, the Air Force unveiled the F-16XL as a competitor in the Enhanced Tactical Fighter (ETF) competition.
The F-16XL lost out, however, to the F-15E Strike Eagle, and the plane never went into production as a result. After losing the competition, though, the modified F-16XL was given a second chance with NASA, who used the jets for high-speed flight research, sonic boom studies, and advanced aerodynamics testing.
The F-16XL: A Regular F-16, But Better
The F-16XL is remembered among aviation buffs as a “what could have been” in the Air Force’s history. Its aerodynamic features were unquestionably superb. Distinct for its cranked-arrow delta wing, the F-16XL provided 120 percent more wing area than a stock F-16, which allowed for twice the ordinance payload (with up to 27 hard points) and significantly improved low-speed handling. In total, the F-16XL had a 633 square foot wing area.
The wing wasn’t the only portion of the aircraft that was modified. The XL-variant also featured a longer fuselage with more internal fuel (up to 13,000 gallons!), giving it roughly twice the range of a conventional F-16. The jet also featured modified landing gear and engine intake to support the increased weight and drag. Between the enlarged fuselage and the extra wing surface area, the F-16XL was significantly larger than the original F-16—thus its designation as an “XL.”
The jet relied on one Pratt & Whitney F100-PW-200 turbofan for propulsion, which supplied 23,770 pounds of thrust when dry and a whopping 29,160 pounds with afterburner. The XL was significantly faster than the stock F-16—topping out at Mach 2.05, or 1,500 miles per hour. The service ceiling was above 50,000 feet, which the jet could reach in just over a minute with its 45,000 feet per minute rate of climb.
Why the F-16XL Lost Out to the F-15 Eagle
The F-16XL finished second to the F-15E Strike Eagle in the 1984 ETF bid. Why? Several strategic, logistical, and technical reasons. The first was safety and survivability. The F-16XL had one engine, while the F-15E had two engines—crucial for deep interdiction missions, where the loss of one engine over enemy territory would almost certainly mean the loss of the aircraft and its pilot. Simply put, the F-16XL was more vulnerable during high-risk missions.
Second, the F-15 airframe was already in production and widely used, so switching gears to the novel F-16XL would require higher development costs, greater logistical changes, and a new maintenance regime and supply chains. Accordingly, the F-15E was deemed to be more cost-effective than rebuilding a similar regime for the F-16XL from scratch.
Third, while the F-16XL represented significant improvements over the conventional F-16, the XL-variant lagged behind the F-15E on a handful of metrics, including total fuel capacity, ordnance flexibility and capacity, and mission duration and loiter time.
Finally, the F-16XL was a victim of strategic inertia. Though its prototype performed well, it was untested in terms of structural stress, avionics integration, and long-term reliability. The F-15, on the other hand, was already combat-proven, making it the much safer choice. The F-15E is still in service, and the Air Force probably does not regret its choice. But the F-16XL was a superlative aircraft that, unfortunately, never got the shot it deserved.
About the Author: Harrison Kass
Harrison Kass is a defense and national security writer with over 1,000 total pieces on issues involving global affairs. An attorney, pilot, guitarist, and minor pro hockey player, Harrison joined the US Air Force as a Pilot Trainee but was medically discharged. Harrison holds a BA from Lake Forest College, a JD from the University of Oregon, and an MA from New York University. Harrison listens to Dokken.
Image: Wikimedia Commons.
