PORTLAND, Ore. (AP) — An off-duty Alaska Airlines pilot struggled with the flight crew as he tried to cut the engines on a regional jet midflight on Sunday, and even tried to grab the handle of an emergency exit after being restrained, federal prosecutors said in charges announced Tuesday.

Joseph David Emerson, 44, of Pleasant Hill, California, was initially arrested in Oregon on Sunday night on state counts of attempted murder after the flight crew reported that he attempted to shut down the engines on a Horizon Air flight from Washington state to California while riding in the extra seat in the cockpit. The plane was diverted to Portland, where it landed safely with more than 80 people onboard.

A federal charge of interfering with a flight crew made public Tuesday said Emerson, who as an off-duty pilot was authorized to ride in the cockpit’s jump seat, made casual conversation with the captain and first officer when the plane was between Astoria, Oregon, and Portland, before trying to grab two red handles that would have activated the plane’s fire suppression system and cut off fuel to its engines.

After what the flight crew described as a brief struggle, Emerson left the cockpit, the U.S. attorney’s office said.

Flight attendants placed Emerson in wrist restraints and seated him in the rear of the aircraft, but as the plane descended, Emerson tried to grab the handle of an emergency exit, the office said in a news release announcing the charge. A flight attendant stopped him by placing her hands on top of his, it said.

The Associated Press has been unable to contact Emerson’s family or others who might speak on his behalf. Court records did not indicate if he has obtained a lawyer.