Here’s what you’ll learn when you read this story:

• In one of the strangest events in Cold War history, a Soviet MiG-23 fighter plane flew without its pilot for 560 miles before crashing into a Belgian farm, killing an 18-year-old.
• The Soviet pilot had ejected from what he believed was a failing jet, but the fighter regained power and kept on flying.
• Two American fighter pilots took to the skies as the Soviet plane entered NATO territory, but didn’t shoot the MiG down for fear of causing casualties in highly populated areas.

The Soviet-made MiG-23 was designed to kill, but certainly not the way it did on July 4, 1989, in arguably the most tragically peculiar Cold War-era event on record. What started as a training exercise for a Soviet pilot ended in death for a Belgian teenager, with the pilot hundreds of miles away at the climax of the situation. And two American pilots watched it all happen.

Shortly after Soviet Col. Nikolai Skuridin took off from the Bagicz Airbase near Kolobrzeg in Poland in his MiG-23 “Flogger” fighter on a routine training mission near the Baltic Sea, the Soviet aircraft experienced an afterburner failure. Seeing smoke spewing from his Flogger, and with the plane descending, Skuridin feared he was moments away from crashing. The Soviet pilot received permission to eject, safely parachuting away from the MiG at an altitude of 400 feet.

But Skuridin never shut the engine down. He simply switched it to a lower power setting, and the ejection was enough to somehow recalibrate the MiG. With the pilot, the ejection seat, and the canopy all jettisoned from the aircraft, the MiG’s center of gravity shifted and the aircraft’s nose tilted upward. Soon the Flogger was climbing, running on autopilot in the same direction Skuridin was heading when he pressed eject. The MiG maintained its take-off speed of 170 knots and eventually reached 35,000 feet in altitude as it traveled over East Germany.

Radar doesn’t allow observers on the ground to determine if a jet fighter has a pilot, though, so as the MiG-23 entered NATO airspace over West Germany, a pair of American F-15s scrambled from Soesterberg in the Netherlands to intercept the enemy fighter. As American pilots J.D. Martin and Bill Murphy approached the MiG-23 from behind, they weren’t quite sure what they were seeing.

“That’s where the eyes play tricks on you,” the pilots said in the book F-15 Eagle Engaged, referring to catching up the “bogey” at supersonic speed and then slowing down to match its pace at 170 knots. “You know, you’re looking at a MiG-23 just like the pictures you’ve studied your entire fighter pilot life, but it just doesn’t add up. What’s he doing here? Why is he alone? And why is he traveling at 170 KCAS?”

That’s when the two pilots noticed something even stranger. The canopy was missing. And so was the pilot. The F-15 pilots said it took 20 minutes of radio traffic for them to convince NATO personnel on the ground that nobody was manning the Flogger.

The initial MiG intercept occurred at 35,000 feet, but the Soviet plane slowly climbed and topped out at 39,500 feet as it flew across the Netherlands and into Belgian airspace. The Soviet fighter was unarmed—it did have machine gun ammunition on board, but who was going to shoot it?—so it posed no immediate threat of deploying conventional or nuclear bombs. That gave NATO decision-makers time to determine what to do. Initial guesses anticipated the jet flying all the way to the English Channel, but that wasn’t to be.

“Then I saw a puff of smoke and a vapor trail: It had obviously run out of gas,” one of the American pilots said in the book. “Then the shallow descent began.”

With no fuel left on the MiG, the Americans armed their fighters, working to determine if shooting it down was the right course of action. Shooting the fighter and breaking it into pieces could prove riskier for civilians on the ground than letting it fall in one piece. As the MiG headed toward Lille, France, on the border with Belgium, calculations showed the Flogger would likely fall a few miles short of heavily populated areas, possibly crashing into sparsely inhabited land filled with fields. The Americans decided to let the pilotless plane continue its gravitational drop.

Originally spotted on radar at 9:42 a.m., the pilotless MiG crashed just under an hour later at 10:37 a.m., roughly 560 miles from where it took off. Unfortunately, the field in west Belgium where it fell wasn’t entirely empty. The MiG hit a farmhouse near Kortrijk, killing 18-year-old Belgian student Wim Delaere.

Skuridin publicly shared his sympathies. “If I could have foreseen such tragic consequences to this pilotless flight,” he said the following day, “I would have stayed in the plane to the end.”