A missing F-35 stealth fighter may have kept flying after its pilot ejected. A pilotless Soviet jet once flew 500 miles before crashing in NATO territory.

• A F-35 stealth fighter went missing after a pilot ejected during a "mishap" on Sunday afternoon.
• It's unclear if the jet was left on autopilot and continued flying or if it crashed somewhere.
• If it kept flying, as reports indicate it may have, it could echo a Cold War incident involving a Soviet aircraft.

The curious case of a missing F-35 stealth fighter in South Carolina has authorities — and civilians — searching high and low, especially considering the jet may have continued flying on its own even after its pilot ejected. 

As surprising as a rogue jet on autopilot may be, it wouldn't be the first time a military aircraft has flown on without its pilot. Toward the end of the Cold War, for example, one Soviet pilot witnessed his jet fly off without him after he ejected from it and continue flying for over 500 miles.

On Sunday afternoon, Joint Base Charleston confirmed a "mishap involving an F-35B Lightning II jet" in which the pilot had to eject. Joint Base Charleston didn't give further details on the incident or what specifically prompted the ejection, but it did request the public's help in locating the missing jet. 

"Emergency response teams are still trying to locate the F-35," the base said on Facebook, adding on X, the site formerly known as Twitter, that if anyone had "any information that may help our recovery teams locate the F-35," they should call in. 

Joint Base Charleston also noted efforts to locate the jet would be focused north of the base, "around Lake Moultrie and Lake Marion," based on the jet's last known location, in coordination with the Federal Aviation Administration.

Officials haven't confirmed or denied if the jet crashed, although Joint Base Charleston spokesperson Jeremy Huggins told NBC News the jet was left in autopilot mode when the pilot ejected from the aircraft, leaving a possibility it could still be airborne. 

The US Marine Corps and Joint Base Charleston didn't immediately respond to Insider's request for comment on whether or not the autopilot was engaged and the possibility that the aircraft could still be flying.

But if the F-35 was still flying in a so-called "zombie state" after its pilot ejected, the bizarre situation would echo a Cold War-era incident involving a pilotless Soviet MiG-23.

In July 1989, Belgium was up in arms after a Soviet MiG-23 fighter jet crashed into a man's home outside the western city of Kortrijk, killing the resident, The New York Times reported at the time. The MiG-23 pilot had apparently ejected while flying over Poland after experiencing an alleged "malfunction."

But rather than crashing, the MiG-23 continued flying for around 560 miles on autopilot, easily passing over East and West Germany and the Netherlands before it finally crashed. The Belgian Foreign Minister at the time noted that the jet had been picked up by NATO radar more than an hour before it crashed, yet there was no Soviet response, including to questions about what weaponry the jet was carrying. 

Another similar incident in which a military aircraft flew on, though not nearly as far, after its pilot ejected is the 1970 "Cornfield Bomber" incident that saw a Convair F-106 Delta Dart interceptor fighter land, surprisingly in one piece, in a farm field in Montana without a pilot.

And as for the currently missing F-35, authorities are still having trouble tracking it. Huggins told The Washington Post the jet's transponder, which helps locate the aircraft, was not working "for some reason that we haven't yet determined." 

The B variant of the F-35 Lightning II Joint Strike Fighter is a short takeoff/vertical landing variant designed for use by the Marine Corps aboard amphibious assault ships and airfields with short runways.

The F-35 is considered to be a highly advanced fifth-generation fighter aircraft known for its high-end capabilities and stealth. Manufactured by Lockheed Martin, the fighter is expensive. A single F-35B is estimated to cost around $90 million, and the 60-year program to develop and maintain the jets expected to cost more than $1 trillion, making it the costliest weapons program in US history.