42nd anniversary of the F-16XL’s first flight

Today marks the 42nd anniversary of the first flight of the F-16XL, a unique prototype fighter jet that never quite reached its full potential. Developed by General Dynamics as a variant of the iconic F-16 Fighting Falcon, the F-16XL boasted a distinctive “cranked-arrow” delta wing design promising increased range and improved ground attack capabilities.

General Dynamics F-16XL (SN 75-0749) in flight 060905-F-1234S-049
USAF, Public domain, via Wikimedia Commons


To delve deeper into the story of this intriguing aircraft, we can turn to the book “General Dynamics F-16XL Dual-Role Fighter: An Illustrated History” by Tony R. Landis. This book, written from the perspective of the U.S. Air Force Materiel Command History Office, offers a comprehensive look at the F-16XL’s design, test program, and ultimate fate.

In his comprehensive work, Landis chronicles the F-16XL’s journey through 248 pages. Over 900 color photographs, 35 black and white photographs, and 125 illustrations bring the narrative to life. Landis traces the history of the two F-16XL prototypes from the early days under the Supersonic Cruise and Maneuvering Prototype (SCAMP) program to the aircraft’s final test flights, research with NASA, and eventual retirement and display in museums.

Landis’ book unveils some interesting trivia about the F-16XL. A unique feature on both prototypes was the “throttle bump” on the left side of the forward fuselage. This bump accommodated the throttle rotation connection, something standard F-16s didn’t need due to their different wing design.

In a cool connection between space exploration and aeronautical development, the book mentions that during separate tours of the F-16XL at NASA Dryden, Apollo 11 astronauts Neil Armstrong and Buzz Aldrin had the opportunity to sign their names on the aircraft.

In the book, Landis briefly mention about the supercruise ability of the F-16XL. In order to achieve the feat, a significant modification involved swapping the standard inlet with the Large Normal Shock Inlet (LNSI) that increased engine air intake by 8 percent. This tweak, along with the F110-GE-129 engine, allowed the F-16XL to achieve “supercruise,” sustained supersonic flight without using the afterburner. Interestingly, Landis mentioned that the U.S. Air Force requested General Dynamics to keep this information quiet to avoid impacting the Advanced Tactical Fighter program. Following this modification, the F-16XL received a new paint job with a distinct gray stripe on the air intake to signify the alteration.

The book also tantalizes readers with details about proposed future variations of the F-16XL that never came to fruition. Landis describes a Wild Weasel variant designed to suppress enemy air defenses. This variant would have sported a dorsal fairing to house the APR-83 avionics suite for radar detection and jamming, and a dedicated launch computer for the AGM-88 HARM anti-radiation missile.

An even more futuristic concept was the advanced Interceptor variant, envisioned for long-range air-to-air combat. This variant would have featured Infrared Search and Track (IRST) sensors and likely Radar Frequency (RF) sensors embedded in the leading edge of the wing for enemy detection. It would have also carried a significant load of long-range air-to-air missiles, resembling the AIM-54 Phoenix but without rear control fins, hinting at the possibility of a next-generation weapon.

Finally, the two-seat Reconnaissance variant prioritized battlefield recon. It would have carried two specialized cameras – KS-87D oblique cameras with various focal lengths for detailed images and a tri-lens wide-angle camera for broader coverage. These cameras would likely have been housed in separate pods for optimal placement. A data link pod atop the vertical stabilizer suggests real-time transmission of reconnaissance data. Notably, the removal of the gun port signifies a complete shift towards gathering intel.

While the F-16XL never entered production, its legacy lives on. The book details how both prototypes now reside in museums, serving as a testament to the innovative design and potential of this aircraft. Landis concludes by expressing his hope that these “elegant machines” will find proper display to preserve the legacy of those involved in their creation.

You may view an online copy of the book using the link below

Source