An American Airlines flight from Los Angeles to Philadelphia was diverted to Phoenix on Thursday after an unruly passenger made "alarming and threatening" statements, according to the Phoenix Police Department.
A spokesman for the airline said Flight 754 left Los Angeles International Airport at 8:38 a.m. with 150 passengers, three infants and a crew of six aboard.
Shortly after the "fasten seat belt" sign was turned off, a man sitting in the front row of the coach section walked toward the front of the plane "as if he was giving a speech to the whole first-class cabin," passenger Chip Yates told NBC affiliate KPNX in a phone interview.
Yates told KPNX he was one of three passengers who helped the flight crew subdue the man, who he said was "angry and swearing and talking about (how) the government was after him."
According to Yates, the man mentioned having an uncle who had been killed in a war and said he "didn't believe the story that was being told to him" about his uncle's death.
Yates said he and two other passengers helped the flight crew "corral" the man into his seat and tighten his seat belt. One flight attendant allegedly brought over a plastic bag containing handcuffs and duct tape, which they had planned to use if the man struggled, according to Yates.
"They weren't kidding around," Yates said of the flight attendants. "That's how you get these kind of safe outcomes."
The plane made an emergency landing at Sky Harbor International Airport in Phoenix, where the man was escorted off the plane and taken to an urgent psychological care center for evaluation, according to police.
They said charges for interfering with the flight crew will be filed against the man, whose name, age and hometown weren't released.
The plane refueled and departed for Philadelphia shortly before noon.
It's the latest in a recent string of plane diversions. Earlier this month, a plane from Los Angeles to San Francisco turned around when one passenger allegedly choked another amid a conflict over a reclined seat. Two days later, an American Airlines flight from San Jose to Dallas was diverted to Phoenix because of a "belligerent passenger."
Generally, however, plane diversions are rare, affecting 1 in 130,000 flights, according to Melanie Hinton, a spokeswoman for Airlines for America, an industry group.
But they can be costly.
The cost of unscheduled landings to disembark or deliver passengers typically can be between $10,000 and $200,000, according to Perry Flint, a spokesman for the International Air Transport Association.
NBC's Ari Mason contributed to this report.