After taking off at the Chinese municipality of Chongqing, passengers and crew sensed something was wrong about half an hour into their flight to the Tibetan capital of Lhasa.

“We experienced a few seconds of free fall before it stabilized again,” one passenger told Chinese media.

That wasn’t just turbulence. At the front of the plane, the pilot was fighting for the life of his colleague — who at that point had been almost entirely sucked out of the plane and was only being held back by his seat belt.

“Suddenly, the windshield just cracked and made a loud bang. The next thing I know, my co-pilot had been sucked halfway out of the window,” said pilot Liu Chuanjian, speaking to Chinese media.