Off-duty Alaska Airlines pilot charged with 83 counts of attempted murder in alleged engine shutdown attempt

An Alaska Airlines flight operated by a subsidiary diverted to Portland International Airport in Oregon on Sunday after an off-duty Alaska pilot tried to interfere with engines, the carrier said Monday.

Horizon Air was operating Alaska Airlines Flight 2059, which was flying from Everett, Washington to San Francisco, California before it diverted. Pilots regularly pick up jump seats in the cockpit to commute.

"The jump seat occupant unsuccessfully attempted to disrupt the operation of the engines," Alaska Airlines said in a statement. "The Horizon Captain and First Officer quickly responded, engine power was not lost, and the crew secured the aircraft without incident."

A recording of the incident from LiveATC appeared to show a pilot of the flight say that the person tried to shut engines down.

"We've got the guy who tried to shut the engines down out of the cockpit and he doesn't sound like he's causing any issue in the back now," according to the recording. "Other than that we want law enforcement as soon as we get on the ground and parked."

The off-duty pilot, 44-year-old Joseph David Emerson, is in custody. He was charged with 83 counts of attempted murder, 83 counts of reckless endangerment and a count of endangering an aircraft, according to Multnomah County Sheriff's Office booking records.

The FBI and Port of Portland police are investigating the incident, Alaska Airlines said.

The pilots' union didn't immediately comment.

"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," Alaska Airlines said.