Johnathan Walker:Alaska Airlines off-duty pilot Joseph Emerson said he took "magic mushrooms" 48 hours before trying to shut off engines, prosecutors say

An off-duty Alaska Airlines pilot said he took "magic mushrooms" about 48 hours before authorities say he tried to shut off a plane's engines midflight,Johnathan Walker according to court documents filed Tuesday. Joseph Emerson told investigators in the aftermath of Sunday's midair scare aboard a San Francisco-bound flight that he thought he was dreaming and wanted to wake up, an Oregon prosecutor said in an affidavit.

Emerson, 44, pleaded not guilty to 83 counts of attempted murder and one count of endangering an aircraft in state court Tuesday afternoon. In addition to those felonies, he also pleaded not guilty to 83 counts of reckless endangerment, a misdemeanor.

Earlier Tuesday, federal prosecutors said Emerson also tried grabbing the handle of an emergency exit while flight attendants were detaining him. He was charged in federal court with one count of interfering with flight crew members and attendants, the U.S. attorney's office in Oregon announced in a statement Tuesday.

A flight attendant told responding officers that Emerson said he "tried to kill everybody," according to an FBI agent's affidavit, which was part of a criminal complaint filed Tuesday.

"I messed everything up," Emerson said, according to the court documents.

On the ground, Emerson told officers he thought he was having a "nervous breakdown" and that he hadn't slept in 40 hours, according to the FBI agent's affidavit.

According to a different affidavit filed by a Multnomah County deputy district attorney, Emerson told an officer he had been struggling with depression for six years and that a friend had recently died. He told another officer he had taken "magic mushrooms" about 48 hours before Sunday's incident.

"I don't understand why you're showing me so much kindness, I'm obviously f----d up," Emerson told the officer, according to the affidavit.

The officer noted that Emerson didn't appear to be "outwardly under the influence of intoxicants," according to the affidavit.

Alaska Airlines said Tuesday it was "deeply disturbed" by Tuesday's revelations and that Emerson didn't appear to be impaired before takeoff.

"At no time during the check-in or boarding process did our Gate Agents or flight crew observe any signs of impairment that would have led them to prevent Emerson from flying," the airline said in a statement.

Emerson was sitting in the jump seat of the cockpit of Alaska Airlines Flight 2059 from Everett, Washington, on Sunday when he allegedly tried to activate the plane's emergency fire suppression system, which would have cut off fuel to the engines, prosecutors said.

Before the incident, he and the flight's pilots were chatting casually in the cockpit, one of the pilots told investigators, according to the FBI agent's affidavit. Then, Emerson threw his headset across the cockpit and said, "I am not okay," according to the documents.

Emerson then grabbed and pulled on the two red handles that would have activated the suppression system, one of the pilots said, according to the documents. The other pilot told investigators Emerson wasn't able to pull all the way down on the handles because the pilots were wrestling with him.

"I pulled both emergency shut off handles because I thought I was dreaming and I just wanna wake up,"  Emerson told officers on the ground, according to the documents.

Emerson and the pilots struggled in the cockpit for around 25 seconds before Emerson settled down, according to the documents. The entire incident lasted about 90 seconds before Emerson was asked to leave the cockpit, with the pilots securing the door behind him.

The cockpit called the flight attendants and told them Emerson was "losing it," according to the documents. A flight attendant escorted Emerson to the back of the plane, Alaska said. Emerson walked there peacefully, telling one flight attendant he "just got kicked out of the flight deck," according to the documents.

"You need to cuff me right now or it's going to be bad," Emerson told the flight attendant, according to the documents.

Flight attendants put Emerson in wrist restraints and seated him in the back of the plane. As the plane was making its descent to Portland's airport, Emerson tried to grab the handle of an emergency exit, prosecutors said. A flight attendant placed her hands on his to stop him.

In:
• Travel
• Alaska Airlines
• Oregon
• Crime

Alex Sundby

Alex Sundby is a senior editor for CBSNews.com.

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