PORTLAND, Ore. — The former Alaska Airlines pilot accused of trying to cut the engines of a Horizon Air flight has been indicted on 84 endangerment charges, but is no longer charged with attempted murder, authorities said Tuesday.

The district attorney’s office in Oregon’s Multnomah County, home to Portland, announced the grand jury’s indictment. Joseph Emerson is scheduled to be arraigned Thursday on 83 charges of recklessly endangering another person — for each person who was on the plane — and one charge of endangering an aircraft. He previously pleaded not guilty to attempted murder charges filed by state prosecutors and to a federal charge of interfering with a flight crew.

In Oregon, initial felony charges can be filed by prosecutors pending a grand jury’s indictment. Such indictments can include different charges, depending on what the grand jury believes is supported by the evidence.

Emerson’s defense lawyers welcomed the grand jury’s decision.

“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,” his defense lawyers Ethan Levi, Noah Horst and Norah Van Dusen said in a statement. “Simply put: Captain Emerson thought he was in a dream.”

Prosecutors have accused Emerson of trying to cut the engines on an Oct. 22 flight from Everett, Washington, to San Francisco while riding in the extra seat in the cockpit. After what the flight crew described as a brief struggle, Emerson left the cockpit, the FBI said in an affidavit. Flight attendants placed Emerson in wrist restraints and seated him in the rear of the aircraft, the affidavit said.

The plane was diverted to Portland, where it landed safely with more than 80 people on board.

According to charging documents, Emerson told Port of Portland police following his arrest that he had been struggling with depression, that a friend had recently died and that he had taken psychedelic mushrooms about 48 hours before he attempted to cut the engines. He also said he had not slept in more than 40 hours, according to the document.

The averted disaster renewed attention on cockpit safety and the mental fitness of those allowed in them.

Emerson remains in custody in Multnomah County.