To assist in the go-around, the controllers had the planes fly a collective "7700."

Here's what happened.

One day, an airplane over Europe turned on its transponder "7700" to signal a distress situation.

While everyone was watching to see what kind of trouble this plane was in, a nearby plane turned on its "7700" signal.

While we were wondering, many other nearby airplanes turned on "7700" one after another.

The alert message on a track monitoring software was a direct hit.

It's a rare sight.

Some suspect a glitch, because the odds of so many planes being in trouble at once are just too slim.

However, it was later confirmed that these distress alerts were real.

It turned out that the airspace suddenly generated some dangerous weather, many airplanes were applying for a go-around, but the surrounding air force was active, the controller might not be able to coordinate with the air force for a while, so he let the airplane fly "7700" while swinging to the air force's airspace to go around the flight, after all, these passengers complained about it, and the control company and the air force might not be able to handle it. After all, if these passengers complain, the control company and the air force may not be able to handle it.