Passengers on a flight to Israel have recounted how they subdued a pilot after he stabbed the other pilot and appeared to be trying to disable the plane, while others described the "terrifying" moment they thought they would die.

Appearing in a bloodstained shirt after the ordeal, Yaniv Hayun told Israeli Prime Minister Benjamin Netanyahu he realised something was wrong when the aircraft suddenly dropped.

The plane, en route from Dubai to Tel Aviv, plummeted 17,000ft (5,200m) in less than two minutes.

"Someone screamed... the light went out," Hayun said in a video posted by the prime minister on social media.

He and others tried to push open the cockpit door, but the pilot who had been stabbed was very close to it, so it was hard to open. Before he collapsed, the injured pilot managed to open the door.

When Hayun and another man entered the cockpit, he said he saw one pilot down and the attacker on the instruments, between the two seats, "trying to destroy the instruments in order to...disable the plane".

"I grabbed the attacker, put him in a chokehold, and pulled him - first and foremost - outside," Hayun said.

"We pulled him out; it was a matter of seconds. I called out to the Israeli guys with us on the plane - I called them, and two other guys came over to me... we pinned [the attacker] down to keep him secure."