A former corrections officer and a Coast Guardsman have been hailed as heroes for helping restrain a violent passenger aboard a Delta flight who threatened to “take the plane down.”

Flight 1249 was en route from Portland, Maine, to Atlanta when a man became unruly.

“I could hear a lot of screaming in the back. One of the passengers was punching the [overhead seat] lights,” James Tennell told Fox 5 Atlanta.

“Passengers were telling me he was wanting to take the plane down,” said Tennell, a former corrections officer who was flying with Ashley Decker.

“He was trying to punch them, punch the windows,” Decker said. “It was kind of scary. 9/11 immediately went into my head.”

Tennell, of Forsyth County, Ga., said that, by instinct, he jumped out of his seat and ran to the back of the plane, where the crazed passenger locked himself in the bathroom.

“Somebody had to do something,” Tennell said.

Another passenger, who identified himself as working for the Coast Guard, also sprang to action.

After the two men told flight attendants they had experience in law enforcement, they were handed handcuffs to restrain the man and return him to his seat.

Tennell said he wrapped the seatbelt through the cuffs.

“He did try to bite me a couple of times,” he said.

Once the plane landed, law enforcement officers whisked the cuffed passenger away.

Tennell advised other passengers to quickly react to danger during a flight.

“There was a lot of lives at stake, where people could have been potentially hurt,” he said.

In a statement to Fox 5, Delta expressed its appreciation to the quick-thinking duo.