An Alaska Airlines passenger tried to force open an emergency exit at 39,000 feet, affidavit says

• An Alaska Airlines passenger tried to open a plane's door midflight, an affidavit says.
• Other passengers said they had heard the man talking to himself and moved away from him.
• After the plane landed safely, the man apologized to the crew, the affidavit said.

An Alaska Airlines flight descended into chaos as passengers restrained a man who was trying to open an emergency exit, an affidavit says.

The incident occurred on last Wednesday's Flight 87 from Deadhorse, Alaska, to Anchorage, a journey that takes about an hour and a half.

During the flight, several passengers had moved seats away from the passenger, named by police as Kassian Fredericks, after becoming concerned by his behavior.

Two men who sat behind him said they heard him talking to himself. One of them told investigators that he mentioned invisible people trying to take over the plane.

He then also took a pill and drank some Gatorade, the witness said.

The Boeing 737 had only been in the air for about eight minutes, climbing through 18,000 feet, when one of the pilots said he got the first call from the cabin crew about their concerns over a passenger's behavior.

Shortly after that, the pilot said, he saw the cockpit light indicating someone was trying to open the emergency exit.

The passenger had managed to move the door's arm upward when another passenger grabbed him.

They called for help, and another two passengers came to restrain him.

"[He] was so strong it took him and the other two male passengers to restrain him and sit him down," the affidavit says.

While it is a frightening situation, it's actually impossible to open a plane door at a high altitude, because the pressure differences inside and outside the aircraft keep the door sealed.

Fredericks is then said to have requested a cigarette, asked about how to break a plane's window, and said he wanted to call his mom.

When one of the passengers asked him why he was trying to open the door, he is said to have replied that he "needed air and to get out of here."

The pilot had considered diverting to an airfield in nearby Fairbanks, but continued onto Anchorage as they were only 18 minutes away, per the affidavit.

Local police then boarded the plane and arrested the passenger.

After landing, the affidavit says, he appeared to have calmed down as he apologized to the crew while he was being escorted away.

Fredericks was indicted by a grand jury on Tuesday and charged with one count of interference with a flight crew, which carries a maximum potential sentence of 20 years.

Alaska Airlines did not immediately respond to a request for comment from Business Insider.