An off-duty pilot tried to disrupt an Alaska Airlines flight's engines before being subdued, airline says

An off-duty pilot riding as a passenger in the cockpit of an Alaska Airlines flight Sunday tried to "disrupt the operation of the engines," forcing the flight en route to San Francisco to divert to Portland, Oregon, the airline said in a statement Monday.

The suspect, identified by police as Joseph D. Emerson, 44, was subdued by the flight crew and taken into custody by the Port of Portland police officers, the port said in a separate statement.

Online booking records show Emerson has been charged with 83 felony counts of attempted murder, 83 counts of reckless endangerment and one count of endangering an aircraft.

After taking off from Paine Field Airport in Everett, Washington, Flight 2059 - one operated by Horizon Air, a regional carrier owned by Alaska Airlines - reported a "credible security threat related to an off-duty Alaska Airlines pilot who was traveling in the flight deck jump seat," the airline's statement said.

Pilots will occasionally ride a cockpit "jump seat" when traveling in an official capacity or commuting to another airport.

Alaska Airlines told CNN the off-duty pilot attempted to shut down both engines by pulling the Embraer 175's engine fire extinguisher handles. The quick reaction of the captain and first officer kept the engines from failing completely, the airline said.

"The fire suppression system consists of a T-handle for each engine; when pulled, a valve in the wing closes to shut off fuel to the engine," Alaska Airlines said in a statement to CNN. "After they are pulled, some residual fuel remains in the line, and the quick reaction of our crew to reset the handles restored fuel flow and prevented fuel starvation."