Videos taken by onlookers during Mr. Russell’s flight showed the plane doing deep dives, broad loops and at least one upside-down roll. At the Seattle-Tacoma International Airport, thousands of passengers in the terminal or left sitting in planes on the tarmac were delayed.
“I got a lot of people that care about me and it’s going to disappoint them to hear that I did this,” Mr. Russell could be heard saying. “I would like to apologize to each and every one of them. Just a broken guy, got a few screws loose, I guess. Never really knew it until now.”
The episode raised questions about the little-known details of life on the tarmac, in the loading, fueling and cleaning operations of airplanes — unglamorous work that is critical to public safety but often poorly paid.
Tim Orr, who also works at the Seattle-Tacoma airport, and who said he had known Mr. Russell since they were both 12, said his friend had been frustrated that his airport job did not pay the $15 minimum wage that many other airport workers receive, and had talked about leaving to do something else. But Mr. Russell, his friend said, also loved the travel opportunities that came with working for an airline.
Mr. Russell and his wife were active church members, Mr. Orr said, “so he doesn’t really fit the bill of someone who would steal an airplane.”
“Funniest person in the room,” he added. “Nicest person in the room.”
Airplane theft, as opposed to hijacking — taking over control in flight, with passengers abroad — is actually not uncommon, though it usually involves private aircraft, not commercial airliners. Colton Harris-Moore, nicknamed the Barefoot Bandit, was sentenced in 2011 for stealing small planes, which he had learned to fly himself as a teenager after reading flight manuals. Drug trade across the United States-Mexico border often happens in stolen planes.
The F.B.I field office in Seattle, which is leading the investigation, said it would cast a wide net in finding out what happened and why. “We are going to be thorough, which means taking the time needed to scour the area, delve into the background of the individual believed responsible, and review every aspect of this incident with all appropriate public and private partners,” the office said in a statement.