A few weeks ago, images began to surface online of an F-117 Nighthawk flying over Nevada and California. Despite being formally retired for more than a decade, a number of these aircraft are consistently maintained in flyable condition, prompting sporadic sightings over the years that never fail to get the aviation community buzzing.

This most recent sighting, however, came with a number of interesting details that aren’t as commonly seen on the rare occasions these birds get to spread their wings. Most notably, a series of unconfirmed reports state that at least four of these stealth aircraft were reactivated to fly combat missions over the Middle East as recently as 2017.

At least one F-117 was spotted conducting low-level, hard-banking maneuvers recently—a style of flying that runs contrary to the Nighthawk’s operational design (as a fairly slow moving, medium altitude, deep penetration bomber). F-16s were also spotted flying at a higher orbit over the area on opposing ends of the valley the F-117 was operating in. And now, perhaps most interesting of all, images snapped of the F-117 during these flights appear to show a tail band touting the name of a squadron that shouldn’t exist.

The band on the tail reads “Dark Knights,” which is a moniker normally associated with the Air Force’s 338th Training Squadron that specializes in airfield systems and ground radar. It seems unlikely that the 338th has anything to do with these F-117 flights, suggesting that their use of the name Dark Knights is probably unrelated.

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The F-117 spotted wearing the Dark Knights tail band has had all other markings removed. So, assuming this Dark Knights squadron actually exists, what exactly does that mean?

Well, it could mean any number of things, ranging from the mundane to the exotic and classified. The most likely explanation is that the team of airmen and contractors tasked with maintaining a handful of these platforms may have simply adopted that name over the years. America’s fleet of F-117s are stored and maintained at the Tonopah Test Range, and the staff tasked with keeping five or six of these birds ready to fly may indeed be called (officially or unofficially) the Dark Knights.

It’s also possible that this aircraft is one of a few activated to serve as part of an aggressor squadron. This was the theory NEWSREP floated when the aircraft was first spotted over Nevada, as its dated stealth characteristics could offer American fighters a valuable opportunity to train at detecting stealth aircraft over different types of terrain and under different circumstances. If those F-16s spotted circling overheard during recent F-117 flights were equipped with the latest in infrared search and track systems (IRST), as Tyler Rogoway at The War Zone has posited, they may have been testing their ability to spot and target stealth platforms using just such a system.

Finally, there’s the possibility that the Dark Knights are an operational squadron flying classified missions like the one rumored to have taken place in Syria in 2017. That possibility, however, seems the least likely, as the United States flies more capable stealth platforms like the F-22 Raptor and F-35 Joint Strike Fighter, the latter of which now harbors the same laser-guided, moving target strike capabilities previously offered only by the F-117.

The name, of course, evokes images of Batman in the minds of many, which seems exactly right for the unusual shape, dark color scheme, and secretive nature of the Nighthawk. The name may mean something, or it may mean nothing at all. But in any regard, it certainly seems fitting.