THIS is the terrifying moment when an enraged passenger attempts to open an emergency door mid-flight – only to be restrained back into his seat.

Frightened travelers watched in shock during the chaotic incident, which caused the flight from Tokyo to Houston on Saturday morning to divert.

Disturbing footage captured the dramatic scene unfolding nine hours into the lengthy journey.

After the passenger suddenly leapt up from his seat, he made a lunge for the door handle on the All Nippon Airways plane.

While most other flyers were fast asleep, two military veterans were luckily still awake during the bizarre stunt.

They quickly hauled the unruly passenger away from the door to stop him from executing his hysterical plan.

The frenzied man was stuck back onto his seat and zip-tied up to prevent him from causing any more chaos.

One of the heroic veterans said: “You’re not going to make it to that window.”

The captain was then forced to divert to Seattle Airport.

Footage showed cops arresting the suspect and taking him to hospital for check ups.

A fellow passenger called Ashley told Fox 26: “He got up in a hurry – I just assumed he was sick.

“But then he went for the emergency exit, and two men jumped into action.”

She added: “They zip-tied him to the seats directly behind me.”

The bystander also described the two men as calm and trained.

“One said he had served in the Navy, and the other had been in for a long time, though I didn’t catch which branch,” she explained.

“They kept him restrained for over an hour.”

As the plane was over Washington state, it diverted to Seattle – just three hours away from its destination in Houston.

The pilots landed just 45 minutes after the shocking ordeal.

But that wasn’t the end for passengers on this chaotic flight.

Ashley said:

Ashely said: “When we landed, a second man on the flight suddenly started acting strange.

Police and medical personnel were already standing on the tarmac when the plane arrived at SeaTac around 4.20am.

They boarded the aircraft and located the crazed flyer immediately.

Audio recording captured one officer saying: “Once I take you out of the seat, we’re going to escort you off the flight, okay?

“If you try to fight us, force will be used against you.”

Both the restrained man and the second strange-acting passenger were escorted off the plane by police.

Airport officials said the main suspect had experienced a “medical episode”.

He was quickly transported to a nearby hospital.

No charges had been announced yet, and the individual’s identity and current condition remain unknown.