The legendary F-117 Nighthawk, sometimes referred to colloquially as the “Stealth Fighter,” may have formally retired in 2008, but sightings of the angular-angel have persisted for years in the skies above America’s southwest. This culminated recently in a series of new sightings near the infamous airstrip of “Area 51,” located in the dry bed that was once Groom Lake in Nevada.

 Theories regarding just what these F-117s may be up to have permeated the aviation-nerd corners of the internet, with many (including myself) postulating that these old-school stealth air frames may be seeing work as aggressor aircraft — or planes that serve as the “bad guy” in air-to-air scrimmages against U.S. fighter pilots. Now it seems that this theory is proving true, thanks to new sightings of the F-117 squaring off against the best fighters in America’s arsenal, including both the F-15 and America’s premiere stealth dog fighter, the F-22 Raptor. Of course, the F-117 doesn’t have any actual air-to-air weapons systems, but it can still serve as a solid stand-in for an aircraft that does.

Plane spotter Kris Tanjano spotted the aerial exercises as the unfolded over the Nellis Test and Training Range in Nevada on December 3. The exercises included a variety of U.S. fighters, including the aforementioned F-15s and F-22s, alongside F-16s and potentially even B-B1 Lancer bombers. Tanjano relayed the full story to Tyler Rogoway at The War Zone, describing an aerial  battle between one F-117 Nighthawk and four F-16 Fighting Falcons as they squared off against America’s air-superiority one-two punch of F-15 Strike Eagles and F-22 Raptors. Tanjano, who listened in to radio communications on the aggressor frequency, confirmed that the F-117’s call sign was, appropriately, “Knight,” with the first two F-16s answering to “Gomer” and “Mig.”

“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. They all fought it out for about five to ten mins then restarted for a second push.” Tanjano relayed.

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“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.”

Tanjano snapped some pictures of the engagement, though most of them depict little more than the triangular-looking F-117 cruising over snowy hills with the distant speck of other fighters in the background. Air to air battles of this sort (even mock ones) are difficult to do justice to via a cell phone camera, after all.

This training revolution seems to prove that the Air Force is using the F-117 as a stand-in for the stealth platforms American fighters may one day find themselves engaging. These could come in the form of Russia’s Su-57 or China’s J-20. The use of the stealthy aircraft alongside fourth-generation workhorses like the F-16 is probably an accurate depiction of how such a battle would play out. The U.S. has the largest stable of stealth platforms in the world; but it regularly explores the ways the F-35’s presence can improve the capabilities of fourth-generation jets in the area. Likewise, with so few stealthy fighters in Chinese or Russian hangars it seems likely that the battle space would include more non-stealthy platforms flying alongside their stealthy counterparts.

It also seems likely that the F-117 serving in the aggressor’s role is meant to help hone the abilities of more than Air Force personnel. As new technologies and tactics develop aimed at curbing the advantage allotted by low-observability, they can be incorporated into drills and tested against the F-117 in realistic environments. This could make American fighter pilots that much more likely to take home a “W” if they ever find themselves squaring off against stealth jets flying another nation’s flag.