By John Woolfolk / The Mercury News

A grand jury in Oregon indicted a San Francisco Bay Area pilot for Alaska Airlines on charges of endangering an aircraft and recklessly endangering others over an October incident in which he allegedly tried to shut off the plane’s engines that led to an emergency diversion to Portland International Airport, prosecutors said Tuesday.

Joseph David Emerson, 44, of Pleasant Hill, who remains in custody at the Multnomah County Detention Center, was scheduled for arraignment at 9:30 a.m. Dec. 7 on the indictment on a charge of endangering an aircraft and 83 counts of recklessly endangering another person, the Multnomah County District Attorney said.

But lawyers for Emerson noted Tuesday that the grand jury did not also indict the pilot on charges of attempted murder for which he originally was charged.

“The attempted murder charges were never appropriate in this case because Captain Emerson never intended to hurt another person or put anyone at risk — he just wanted to return home to his wife and children,” said a statement from Emerson’s lawyers, Ethan Levi, Noah Horst and Norah Van Dusen.

“While we are pleased that the grand jury correctly determined that the attempted murder counts were inappropriate in this case, we were disappointed to learn that the grand jury did indict Captain Emerson for a single count of endangering an aircraft and 83 misdemeanor counts of recklessly endangering another person,” his lawyers’ statement continued.

“Captain Emerson had no criminal intent, and we look forward to being able to present a fulsome defense at trial and bring forth all the facts and circumstances to a jury,” Emerson’s lawyers said, adding they are “crafting a release plan and expect that he will finally return home to his family by the end of this week.”

Emerson was off-duty on Oct. 22 and riding in an extra cockpit “jump seat” on Horizon Air flight 2059, an Embraer 175 that left Everett at 5:23 p.m. headed for San Francisco, when prosecutors and airline officials said he suddenly threw off a headset, said “I am not OK” and reached for the engine shutoffs.

The plane’s pilots wrestled Emerson’s hands off the overhead engine shutoff handles, safety features designed to cut off fuel to them in the event of a fire, and he calmed soon after and left the cockpit on his own and took a seat in the rear of the aircraft while the pilots landed the plane in Portland, court documents said.

Had Emerson succeeded in shutting off the engines, pilots later told police, it would have turned “the aircraft into a glider within seconds,” jeopardizing the lives of all aboard, court documents said.

Alaska Airlines, which owns Horizon Air, said in a statement that Emerson had first joined Alaska Air Group as a Horizon copilot in August 2001, left to become a Virgin America pilot in June 2012, returned to Alaska following the airline’s acquisition of Virgin America in 2016 and became a captain in 2019. Alaska said he’d completed his mandated FAA medical certifications and at no point were his certifications denied, suspended or revoked.

The pilots on the Horizon flight said nothing seemed amiss with Emerson when he boarded for a courtesy flight back home, and neighbors said they were shocked about his arrest and that it seemed out of character.

But Emerson told police, according to prosecution affidavits, that he’d been depressed over the death of a close friend and had taken “magic mushrooms” for the first time about 48 hours before the flight, though an officer noted that he “did not observe Emerson to be outwardly under the influence of intoxicants.”