Key point: The F-117 was a revolutionary plane. It still is useful, although it should soon no longer see service given its increasing age.

Eleven years after the U.S. Air Force officially retired the type, an F-117 Nighthawk stealth fighter has made yet another public appearance.

Plane-spotter Kris Tanjano was posted up outside the Nellis Test and Training Range in Nevada on Dec. 3, 2019 when he witnessed an aerial exercise play out overhead. F-117s apparently flying from Tonopah Test Range were in the mix along with F-16s, F-15s, F-22s and possibly B-1 bombers coming from Nellis Air Force Base.

The Lockheed-made stealth fighters apparently were acting as radar-evading adversaries in a mock battle with other plane types, Tanjano told Tyler Rogoway at The War Zone. “I witnessed an F-117 along with four F-16s go up against F-15s and F-22s. The F-117's callsign was KNIGHT, the F-16s were GOMER and MIG, and they were communicating on the aggressor frequency.”

“First, the F-16s came in pairs attacking the blue force (F-22s, F-15s, and maybe a B-1) then an F-117 came in at low-level just behind the F-16s towards the blue force,” Tanjano added. “They all fought it out for about five to 10 minutess then restarted for a second push. Once again the F-16s came high overhead, followed by a low-level F-117. Several times the aggressors called out a target which was a low-level heavy aircraft which I believe was B-1, but I am not certain.”

The sighting seems yet again to confirm what Rogoway long has suspected. “Having a small aggressor force of F-117s available for putting our and our allies' latest radars, infrared search and track and electronic emissions detection system to the test, as well as to develop tactics for defeating such threats, seems like a perfect job for the F-117.”

The first of 59 front-line F-117s became operational in the mid-1980s and most famously led deep strike missions targeting Iraqi forces during the 1991 Gulf War. F-22 stealth fighters in 2008 assumed the F-117s’ strike role pending the 2016 introduction of F-35 stealth fighter-bombers.

The Air Force packed many of the F-117s into a storage hangar at Tonopah. But some of the “retired” Nighthawks continued to fly on secretive missions. Amateur plane-spotters packing powerful cameras photographed and videotaped F-117s flying over the desert test range and taxiing on its remote runway, sometimes singly and sometimes in pairs.

Nighthawks also showed up on the ground. Photographer Chris McGreevy on Aug. 16, 2019 spotted a truck hauling an F-117 on Columbia Way near the Palmdale Regional Airport outside Palmdale, California.

Richard VanderMeulen on Feb. 26, 2019 photographed a single, unmarked F-117A flying over the restricted air space R-2508 range complex near Death Valley in southern California.

The photos, first published in Combat Aircraft, depicted an F-117 with partially worn or obscured markings flying at low altitude around the mountains. The aircraft made another brief appearance the next day.

The February 2019 sighting was notable for taking place outside of the air space around Tonopah Test Range, the F-117’s usual haunt. In a sort of preview of the December 2019 sighting, the Nighthawk appeared in the company of two F-16s.

“The F-16s may very well have been putting a new infrared search-and-track pod to the test or some other sensor system, or maybe they were just all out for a flight through the area to keep up basic competency,” Rogoway wrote. “We just don't know.”

Why would the Air Force want to keep a few Nighthawks operational, despite their age, complexity, high cost and the fact that Serbian air-defense forces figured out how to detect the planes and actually shot one down during the 1999 U.S.-led air war on Serbia?

Rogoway has ideas. “The F-117 is an incredibly valuable and well-understood stealthy target to test new sensor systems against and new low-observable (stealthy) coatings on.”

“On the radar and infrared tracking side of the argument, the F-117 is ... a near-perfect and highly available low-observable aircraft to test everything from ground-based radars and [surface-to-air missile] systems, both foreign and domestic, AWACS modifications, fighter radars and even infrared search-and-track systems.”

But the stealth fighters won’t last forever, Rogoway explained. “The F-117s are slowly disappearing into the abyss. Congress's former mandate to keep the fleet of roughly 52 jets in Type-1000 regenerative storage indefinitely at the high-security Tonopah Test Range Airport has ended.”

The Air Force plans annually to remove four F-117s from storage and dispose of them. At that rate, the remaining Nighthawks could disappear for good some time in the 2020s.

David Axe served as Defense Editor of the National Interest. He is the author of the graphic novels  War Fix, War Is Boring and Machete Squad. This first appeared in 2019 and is being reposted due to reader interest.

Image: Reuters