What you need to know: The US F-16 fighter jet has served admirably since its introduction in the 1970s and remains a valuable multi-role asset. The F-16XL, an improved variant, was designed to achieve supercruise capabilities, carry a double payload and provide extended range, but was ultimately passed over for the F-15E Strike Eagle.

– In particular, the F-16XLs were used by NASA for aerodynamic research in the 1990s, contributing to later developments such as the supercruise capabilities of the F-22.

-Today F-16XL prototypes are kept in museums, celebrated as impressive “F-16s on steroids” for their advanced payload capacity, range and maneuverability, even though they never entered active service.

The F-16XL: A Missed Opportunity in Air Superiority?

America’s Formidable Fourth Generation F-16 fighter the platform made headlines last year when the White House gave Ukraine the green light to fly them to war.

As of February 2022, Kiev stated that without being more advanced aerial capabilitieswould be unable to thwart Russian advances.

Initially, the Biden administration was adamant that it would not provide F-16 Fighting Falcons to aid Ukraine’s defense efforts. However, the training of Ukrainian pilots on these aircraft was finally approved.

U.S. Defense Secretary Lloyd Austin said the U.S. will actually lead the coalition of nations that will train Ukraine’s pilots and aircrews to accordingly exploit the Fighting Falcons. F-16 fighter jets are now fighting Russia in the sky.

A brief history of the F-16 platform

The General Dynamics F-16 was designed nearly five decades ago to meet the US Air Force’s need for an air superiority fighter.

In the wake of the Vietnam War, military officials understood the need for better equipped aircraft to maneuver with the least possible loss of energy.

In the 1970s, the Fighting Falcon was born out of the Lightweight Fighter program.

The compact, multi-role aircraft is highly maneuverable and can operate in both air-to-ground and air-to-air combat.

Over the years, The F-16 platform achieved an honorable combat record and continues to fly for the USAF as well as a litany of foreign militaries.

Where are the F-16XLs today?

While the F-16 has an honorable heritage, not all of its later variants made it into service.

Shortly after he won Lightweight Fighter Program contract, General Dynamics worked on several prototypes, including two variants that it later delivered to NASA’s Langely Research Center.

Referred to by their serial numbers #849 and #848, these aircraft were both used in a litany of experiments that only ended in the late 1990s.

In particular, F-16XL #849 participated in a 1995 sonic boom study where it flew 200 feet behind a NASA. SR-71 to establish the supersonic shockwave limit of an SR-71.

As explained by Peter Suciu regarding additional F-16XL studies by NASA: “The two-seat F-16XL was extensively modified by NASA Dryden for the Supersonic Boundary Layer Control research project in the mid-1990s. A turbine-driven intake system was installed in the fuselage aircraft, while a modified, thickened left wing pulled air from the boundary layer flowing over the wing to allow laminar or smooth airflow over the wing. The aircraft last flew in 1996 and appears to be no longer airworthy.”

Although these variants are now stored at the Edwards Air Force Flight Center Museum and on display at the Museum Air Park, they are highly respected by aviation enthusiasts and industry experts alike.

F-16XL: F-16 on steroids?

The resulting F-16XL design was conceptualized to potentially replace the F-111 Aardvark. Ultimately, however, McDonnell Douglas’ F-15E jet was awarded the contract. The two F-16XL fighters built were then relegated to Edwards Air Force Base.

The main concept driving the F-16XL was supercruise (sustained supersonic cruise without afterburner) capability. The peak prototype did indeed have a longer range while saving fuel.

Despite the F-16XL’s trajectory, the fighter jet is widely recognized by aviation experts as a powerhouse.

According to Military.com, this variant would carry twice the payload of the original Fighting Falcon and fly up to 44% farther.

Additionally, the F-16XL could accomplish this without external fuel tanks and while having a full suite of air-to-air weapons, including four AMRAAMs and two AIM-9 Sidewinders.

Additional capabilities were contour by the Air Force and Space Force: “In terms of penetration and survivability, the F-16XL can attack supersonic with a bomb load at high or low altitude. It can climb at high speeds with bombs on board. And it has a speed advantage of up to eighty-three knots over the F-16A at sea level at the military power setting and 311 knots afterburning at altitude while carrying a bomb load.

Two additional capabilities of the F-16XL contribute to survivability. The first is the improved instantaneous maneuverability coupled with the very extended flight operating limits (with bombs), and the second is the reduced radar signature resulting from configuration modeling.

Did the Air Force make a mistake?

While the Strike Eagle platform did possiblyand entered service with the USAF proved to be very capable, the F-16XL would undoubtedly have improved service prowess had it been accepted alongside the F-15 back in the day.

However, the F-16 contributed to modern air concepts. In fact, the variant would even help develop the supercruise capability of the first fifth-generation aircraft to take to the skies – the F-22 Raptor.

About the author: Maya Carlin

Maya Carlin is an analyst at the Center for Security Policy and former Anna Sobol Levy Fellow at IDC Herzliya in Israel. She has written for many publications, including The National Interest, the Jerusalem Post, and the Times of Israel. You can follow her on Twitter: @MayaCarlin.

All images are Creative Commons.