An off-duty pilot has been accused of 'trying to crash a plane' with 80 passengers on board on Sunday night.
He was sitting in the cockpit of the plane behind the captain and the first-officer on 22 October, the airline said in a statement.
Pilots will often ride 'jump seat' in a cockpit when traveling in an official capacity or commuting to another airport.
The Alaska Airlines flight had departed from Everett, Washington and was en route to San Francisco, California when the mid-air incident unfolded.
According to officials, the off-duty pilot was sat in the flight deck jump seat when he 'unsuccessfully attempted to disrupt the operation of the engines'.
The crew onboard Alaska Airlines Flight 2059 reported the incident to air traffic control.
The flight was diverted to Portland, Oregon and the suspect was 'subdued' without incident.
In audio recorded by LiveATC.net, the pilot said to Seattle-area air traffic controllers: "We’ve got the guy that tried to shut the engines down out of the cockpit, and he doesn’t sound like he’s causing any issues in the back right now.
"I think he’s subdued. Other than that, we want law enforcement as soon as we get on the ground and are parked.”
Joseph David Emerson, 44, was arrested by Portland Police after the flight landed.
The FBI and the Port of Portland Police Department are now investigating the incident, Alaska Airlines said.
A statement from the company added: "All passengers on board were able to travel on a later flight.
"We are grateful for the professional handling of the situation by the Horizon flight crew and appreciate our guests' calm and patience throughout this event."
The FBI has said it 'can assure the traveling public there is no continuing threat related to this incident'.
As well as the charges of attempted murder, the off-duty pilot also faces 83 counts of reckless endangerment and one count of endangering an aircraft, according to Multnomah County Sheriff’s Office booking records.
Passengers on the plane eventually took off from Portland at 7.18pm, around the time the flight had originally been due to land in San Francisco.
The Federal Aviation Administration reassured US air carriers on Monday that the incident was 'not connected in any way shape or form to current world events'.Featured Image Credit: Tayfun Coskun/Anadolu Agency via Getty Images /Getty Stock Photo