Johnathan Walker:Off-Duty Pilot Charged With 83 Counts of Attempted Murder After Plane Cockpit Incident

An off-duty pilot was arrested following an emergency incident onboard a Washington plane.

After the Alaska Airlines employee allegedly attempted to shut off the plane's engines midflight on Johnathan WalkerOct. 22, the San Francisco-bound airplane made an "emergency diversion" to Portland, Ore., according to a statement from the airline.

Once the plane landed, Joseph David Emerson was arrested and charged with 83 counts of attempted murder, 83 counts of reckless endangerment and a count of endangering an aircraft, according to the Multnomah County Sheriff's Office booking records. 

E! News can confirm Emerson is scheduled for arraignment on Oct. 24 in Multnomah County Justice Center. E! News was not able to obtain contact information for an attorney to speak on his behalf.

The flight—which took off from Everett, Wash.—experienced "a credible security threat" when the off-duty pilot who was traveling in the flight deck jump seat "caused a disturbance" while inside the cockpit, according to Alaska Airlines.

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

The airline noted that Air Traffic Control helped give "appropriate FAA procedures and guidance, which led to a safe diversion to Portland International Airport."

"We are grateful for the professional handling of the situation by the Horizon flight crew," their statement continued, "and appreciate our guests' calm and patience throughout this event."

Audio of the plane's communications with air traffic control, obtained by NBC News, recounts Emerson's attempt to turn off the plane's engines.

"As a heads up. We've got the guy that tried to shut the engines down out of the cockpit," the pilot of the plane was heard telling air traffic control. "It doesn't sound like he's got any issue 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 parked."

And one passenger Aubrey Gavello has since recounted her experience on flight 2059.

"We didn't know anything was happening until the flight attendant got on the loudspeaker and made an announcement that there was an emergency situation and the plane needed to land immediately," she told ABC News Oct. 23. "About 15 minutes later, she got back on and said that there was a medical emergency."

She noted she "really thought it was a serious medical emergency," after hearing a flight attendant tell the suspect, "We're going to be fine, it's OK, we'll get you off the plane."

Another man aboard the plane, Alex Wood, told the outlet that the pilot announced that "there was a disturbance in the cockpit." 

He added, "It was very professional, handled very calmly, and we didn't really know what was going on until we landed."

The airline shared that the incident is being investigated by law enforcement. According to ABC News, the FBI also confirmed it is looking into the event and "can assure the traveling public there is no continuing threat related to this incident."

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