Off-duty pilot charged with 83 counts of attempted murder after incident on Horizon Airlines flight to San Francisco.

The pilot, who was occupying the cockpit jump seat, attempted to disable the aircraft’s engines during a Horizon Airlines flight from Everett, Washington, to San Francisco, California, before he was subdued by the flight crew, officials said on Monday.

Joseph David Emerson, 44, was arrested after the plane landed safely in Portland, Oregon, on Sunday, according to the local prosecutor’s office.

He faces 83 counts of attempted murder, 83 counts of recklessly endangering another person and one count of endangering an aircraft.

The FBI in Portland said there was “no continuing threat related to this incident”.

The Federal Aviation Administration told US airlines in a notice that a “validated jump seat passenger” had sought to disable the engines of the twin-jet Embraer 175 by trying to activate the engine fire-suppression system.

One of the plane’s pilots told an air traffic controller that the crew had “got the guy that tried to shut the engines down out of the cockpit, and he doesn’t sound like he’s causing issues in the back right now”, according to an audio recording posted on LiveATC.net. “I think he is subdued.”

Seattle-based Alaska Airlines, which owns Horizon, on Monday confirmed that one of its pilots had been involved in the incident, but said the captain and co-pilot “quickly responded, engine power was not lost and the crew secured the aircraft without incident”.

Airlines use the cockpit jump seat to accommodate pilots preparing to fly a later flight to avoid bumping a passenger off the plane. US carriers also often let pilots from other airlines occupy the third seat.

In 2018, a Horizon Air ground agent crashed a plane into a small island in Puget Sound after stealing an empty aircraft at Seattle’s Sea-Tac International Airport.

The man told an air traffic controller that he “wasn’t really planning on landing” and described himself as “a broken guy”.