Out-of-control Alaska Airlines passenger tries to opens plane door mid-flight

An erratic Alaska Airlines passenger allegedly tried to open a cabin door mid-flight — sparking fellow passengers to restrain him and a storm of bizarre rambles, according to court documents.

Kassian William Fredericks was on board Alaska Airlines flight 87 en route to Anchorage last Wednesday when he allegedly ran to the cabin door and tried to pry it open, according to an FBI probable cause affidavit obtained by The Post.

A passenger sitting a few seats behind him left to use the bathroom, and when he returned, found Fredericks “aggressively trying to open the rear cabin door,” the affidavit said.

The passenger bolted over to Fredericks, who had already managed to lift the arm of the cabin door upward, and grabbed him.

The hero passenger then yelled to two other male passengers, who rushed to help restrain Fredericks and sit him back down.

Fredericks kept trying to stand up and repeatedly told the passenger, “I need to call my mom,” and also asked for a cigarette, documents alleged.

“How do I break the window? I don’t know how to break it,” Fredericks allegedly told the passenger, who then stated he tried to open the cabin door because he “need[ed] air and to get out of here,” the filing alleged.

Fredericks was shaking during the interaction, the affidavit said.

Before the incident, another passenger who helped restrain him had heard Fredericks yell out, “Stop the plane, stop the plane,” while repeatedly turning his head to the aircraft.

When the passenger asked him if he was okay, Fredericks said, “They’re flying the plane from back here,” clarifying, “No, they’re invisible. They’re trying to take over the plane. You got to stop them.”

The passenger then saw Fredericks “pop a pill in his mouth” and take a sip of Gatorade. The passenger thought the pill could calm him down, but then he proceeded to act more off the wall, the document said.

Flight crew told law enforcement that they did not believe Fredericks was drunk, but had noticed him acting “weird and off” and assumed his shaking was from a possible medical condition.

After becoming aware he had allegedly tried to open the cabin door, the flight crew “wanted to restrain [Fredericks] with zip ties,” but decided it “might make [him] act worse and escalate the situation,” the filing stated.

Though it is practically impossible to open the cabin door mid-air due to air pressure, the move could have triggered the emergency slide to deploy and inflate within the plane — seriously harming passengers, the affidavit detailed.

The pilot contacted ground controllers, which brought in the FBI, and escorted Fredericks off the plane upon landing in Anchorage.

Fredericks “apologized to the crew and seemed to have calmed down when he was being escorted off the plane,” the document said.

While at the hospital, a police officer overheard Fredericks telling a doctor he “had been drinking alcohol for the last nine to 10 days,” was seeing and hearing things, and “could not remember the last two years of his life,” according to the affidavit.

He also allegedly told doctors he was taking the prescription Trazodone, which is used to treat depression, anxiety, and insomnia.

In a statement to The Post, Alaska Airlines said Fredericks has been banned from flying with the airline.

“A passenger onboard Alaska Airlines Flight 87 from Deadhorse, AK (SCC) to Anchorage (ANC) displayed erratic behavior and attempted to open one of the emergency doors,” an Alaska Airlines spokesperson said.

“The passenger was intercepted and restrained until the aircraft landed safely in Anchorage, where it was met by law enforcement and EMTs,” the statement continued.

“The passenger who caused the incident has been banned from flying with us. We thank our crew for their professionalism in handling this situation, and we apologize to our guests for any concern this incident caused.”

Fredericks was later arrested and charged with interference with flight crew members. If convicted, he faces up to 20 years in prison.

Fredericks’s attorney did not immediately respond to The Post’s request for comment.