The airline employee who hijacked an empty Horizon Air turboprop plane from Seattle’s international airport and crashed it on a nearby island had security clearance and was on his shift, airline officials say.
The 29-year-old man, identified by the US media as Richard Russell, had worked for Horizon Air for more than three years, towing and tidying aircraft and loading bags.
Russell used a machine called a pushback tractor to manoeuvre the 76-seater Q400 Bombardier airplane so he could board and then take off from Sea-Tac International Airport on Friday evening.
The flight, which lasted for almost an hour, forced authorities to ground all flights at the airport while traffic control tried to persuade the man to land the plane. A number of F-15 fighter jets were scrambled out of nearby Portland, Oregon, to chase the aircraft.
After making "incredible manoeuvres," the hijacker crashed the plane and was killed near a military facility on Ketron Island, a sparsely populated area in Puget Sound.
WATCH LIVE: SkyKING over plane crash on Ketron Island. Airport employee stole plane from Sea-Tac and crashed shortly after >> https://t.co/TAFsPYG2Ub pic.twitter.com/57XiUTXzTk
— KING 5 News (@KING5Seattle) August 11, 2018
"At this time, we believe he was the only one in the aircraft but of course, we haven't confirmed that at the crash site," said Jay Tabb, chief of the FBI's Seattle division.
Russell did not possess a pilot's license, leaving airline authorities wondering how he conducted loops in the aircraft before crashing.
Officials said he went through a number of background checks to gain clearance to be in the secured area of the airport.
The plane broke into pieces upon the crash but investigators expressed hope they would be able to recover the aircraft’s data recorders.
Alaska Airlines said in a statement that the Federal Aviation Administration, the Federal Bureau of Investigation and the National Transportation Safety Board are all investigating the incident.
A large part of the probe will focus on how the man managed to steal a plane and fly it.
Experts say the incident will likely prompt a review of the already tightly-controlled security measures at airports.