The theft and crash of an empty commuter plane by an airline worker in Seattle on Friday revealed a security vulnerability that authorities have known about for decades, a former top transportation official said Sunday.
John Pistole, a former head of the Transportation Safety Administration and now president of Anderson University, told NBC News in an interview that the Federal Bureau of Investigation, the TSA and others have looked at so-called "insider threats" that could target airports since before the attacks on Sept. 11, 2001.
While their potential dangers are "clearly of great concern to everybody in the aviation industry," Pistole said, airlines, airports and the federal government tend to focus on high-risk threats — using an aircraft filled with people as a weapon, for instance.
An event like Friday's "slipped under the radar," said Pistole, who is also a former deputy director of the FBI under President George W. Bush.
"There well maybe some changes ... at airports and by airlines," Pistole said. "But the challenge is: how do you best identify what's in somebody's mind?"
Pistole, who lead the TSA from 2010 to 2014, recalled the case of Andreas Lubitz, a 27-year-old Germanwings pilot who authorities said deliberately crashed an Airbus A320 in 2015, killing all 150 people on board. Lubitz had no criminal record or terrorist connections — though authorities said he concealed a doctor's note from the airline that described him as unfit for work.
The theft in Seattle, Pistole added, highlighted "a vulnerability that is still existing here, almost 17 years after 9/11."
Erroll Southers, the former chief of the Office of Homeland Security at Los Angeles International Airport, said that vulnerability easily could have ended more disastrously.
"Certainly someone who can do barrel rolls with a prop plane could have flown into a building or into a crowd," he said. "He decided not to."
Courtney Gregoire, commissioner of the port of Seattle, told reporters Monday that all security protocols were followed Friday.
"I think this is really, truly one in a million experience," she said. "That doesn't mean we can't learn from it and ensure this type of tragedy doesn't happen again."
Authorities have said that 29-year-old Richard Russell passed multiple criminal background checks before he began working as a ground service agent with Horizon Air at Seattle-Tacoma International Airport nearly four years ago.
On Friday, however, Russell — who worked on a tow team moving aircraft — used a tractor to taxi an empty Q400 turboprop plane. Though he wasn't trained as a pilot, Russell took off around 7:30 p.m. (10:30 p.m. ET) and performed aerial maneuvers before crashing roughly an hour later on Ketron Island.
While speaking with an air traffic controller, Russell cracked jokes and said he learned to fly from video games, according to audio released by investigators.
He also described himself as a "broken guy" with "a few screws loose."
A childhood friend and former football teammate of Russell's in Alaska, Zach Orr, said in an interview that while Russell showed no signs of depression, he may have suffered from chronic traumatic encephalopathy, or CTE, the rare brain disease that can cause memory loss, suicidal thoughts and impulsive behavior, among other symptoms.
A recent study of 202 football players found evidence of the condition in nearly all of them.
"I don't remember a time where he and I would square off in practice and I didn't get my bell rung going up against him," Orr said. "He was a tough player."
Their team at Wasilla High School played with decade-old helmets that didn’t fit properly, Orr said, adding that many of his former teammates have "had issues."
Jeff Price, an aviation security expert, said an event like Friday's is an "anomaly" — "this is not something that's in the normal vocabulary range when we talk about aviation security," he said — but he cautioned that the industry and regulators need to examine the vulnerabilities that allowed it to occur.
"Is there somebody someone can call and say, 'Look this guy came to work today and something's really just not right — he really needs some help,'" Price said.
"The other thing they do need to look at is the unfettered access to the aircraft by people who aren't pilots. There might need to be a procedure in place where if you're not a pilot or flight attendant, you're not allowed on the plane unless there is someone there that that is responsible for the aircraft."