An off-duty pilot is facing multiple counts of attempted murder after an Alaska Airlines flight was forced to divert Sunday when he created a security threat while trying to disrupt the flight, officials said Monday.

The pilot riding in the cockpit of a Horizon Air passenger jet tried to shut down the engines in midflight. Horizon Air runs regional flights for Alaska Airlines.

The San Francisco-bound flight had departed Everett, Wash., and was forced to divert to Portland, Ore. The off-duty pilot, identified by the Multnomah County Sheriff's Office as Joseph Emerson, 44, was charged with 83 counts of attempted murder, 83 counts of reckless endangerment and one count of endangering an aircraft. No injuries were reported.

Alaska Airlines said in a statement that Emerson "attempted to disrupt the operation of the engines."

The FBI's Portland office said one person was in state custody in connection with the incident, which took place aboard Alaska Airlines Flight 2059. The FBI said the pilot was able to safely land the plane at Portland International Airport about 6:25 p.m. local time Sunday.

The incident was caused by the off-duty pilot in the flight deck jump seat, authorities said. The jump seat is an additional seat in the flight deck typically reserved for employees of the Federal Aviation Administration or the airline.

"The FBI is investigating and can assure the traveling public there is no continuing threat related to this incident," Kieran L. Ramsey, special agent in charge of the FBI's Portland division, said in a statement.

Airline officials said the flight's captain and first officer quickly responded, engine power was not lost and the crew secured the aircraft without incident.

"We are grateful for the professional handling of this situation by the Horizon flight crew and appreciate our guests' calm and patience throughout this event," Alaska Airlines said in a statement.

The flight was diverted, and Emerson was taken into custody. Passengers were able to travel on a later flight.

The FAA said that it is engaged with Alaska Airlines and that Horizon is supporting the law enforcement investigation.