Officials said Saturday that the man was a 3.5-year Horizon Airlines employee and had clearance to be among aircraft, but that to their knowledge, he wasn't a licensed pilot.
The 29-year-old used a machine called a pushback tractor to first maneuver the aircraft, which was in a maintenance area, so he could board and then take off Friday evening, authorities said.
A U.S. official briefed on the matter told The Associated Press the man was Richard Russell. The official wasn't authorized to discuss the matter and spoke on the condition of anonymity.
Video showed the Horizon Air Q400, a turboprop plane that seats 76 people, doing large loops and other dangerous maneuvers as the sun set on Puget Sound.
Two F-15C aircraft were scrambled from Portland and pursued the plane but authorities say they didn't fire on it before it crashed on tiny Ketron Island, southwest of Tacoma, Washington. Video showed fiery flames amid trees on the island, which is sparsely populated and only accessible by ferry. No structures on the ground were damaged by the plane, which sparked a small wildfire.
"It is highly fragmented," Debra Eckrote, the Western Pacific regional chief for the National Transportation Safety Board, said of the plane. "The wings are off, the fuselage is, I think, kind of positioned upside down."
Investigators expect they will be able to recover both the cockpit voice recorder and the event data recorder from the plane.
Russell is presumed to have died in the crash.
He could be heard on audio recordings telling air traffic controllers that he is "just a broken guy."
An air traffic controller tried to convince him to land the airplane.
"There is a runway just off to your right side in about a mile," the controller says, referring to an airfield at Joint Base Lewis-McChord.
"Oh man. Those guys will rough me up if I try and land there," the man responded, later adding "This is probably jail time for life, huh?"
Later the man said: "I've got a lot of people that care about me. It's going to disappoint them to hear that I did this ... Just a broken guy, got a few screws loose, I guess."
Russell's family said in a statement that they are stunned and heartbroken. They referenced the recordings of him talking to air traffic controllers and said and that it's clear Russell, who went by the nickname "Beebo," didn't intend to harm anyone and "he was right in saying that there are so many people who loved him."
Horizon Air is part of Alaska Air Group and flies shorter routes throughout the U.S. West. The Q400 is a turboprop aircraft with 76 seats.
At a news conference in Seattle-Tacoma International Airport, officials from Alaska Airlines and Horizon Air said that they are still working with authorities as they investigate what happened.
"Last night's event is going to push us to learn what we can from this tragedy so that we can ensure this does not happen again at Alaska Air Group or at any other airline," said Brad Tilden, CEO of Alaska Airlines.
The bizarre incident involving a worker who authorities said was suicidal points to one of the biggest potential perils for commercial air travel: airline or airport employees causing mayhem.
"The greatest threat we have to aviation is the insider threat," Erroll Southers, a former FBI agent and transportation security expert, told the AP. "Here we have an employee who was vetted to the level to have access to the aircraft and had a skill set proficient enough to take off with that plane."
Ground service agents direct aircraft for takeoff and gate approach and de-ice planes, as well as handle baggage.
There was no connection to terrorism, said Ed Troyer, a spokesman for the sheriff's department.
Coaches at Wasilla High School in Alaska, where Russell was a football player, wrestler and discus thrower, told the Anchorage Daily News they are shocked at the news.
Track and field coach Gary Howell said he was "absolutely the kind of kid you want on your team."
"He had that energy, that vibrance," Howell said. "He was that kid you high-five in the hallway even if you don't know him."
On social media pages, Russell said he lived in Sumner, Washington, and was married in 2012.
In a humorous YouTube video he posted last year, he talked about his job and included videos and photos of his various travels.
"I lift a lot of bags. Like a lot of bags. So many bags," he said.
Ridler reported from, Idaho. AP reporter Mike Balsamo in Los Angeles contributed to this report.
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