Shocking footage shows the moment an American Airlines passenger attacked a unsuspecting flight attendant – sneaking up behind him and sucker punching the staffer aboard a flight from Mexico to Los Angeles.

It happened on Flight 377, from San Jose del Cabo in Mexico to LAX on Wednesday. The passenger was removed from the plane upon landing stateside.

Upon arriving at the airport, the suspect – who has not been named – was detained on suspicion of interfering with a flight crew.

If found guilty of the offense, a federal felony, the man – who allegedly threatened the male attendant before the filmed attack – could face up to 20 years in prison.

According to some reports, the incident started when the suspect began to mumble nonsensically Reports claim that there were 10 ‘killers’ on the California-bound aircraft.

At that point, a female flight attendant reportedly went back to address the man, with the the male attendant who was attacked joining to assist, passengers said.

Barrie Livingstone captured video of the moment. He shows the flight attendant, standing across the aisle from the passenger.

Shocking footage shows the moment an American Airlines passenger attacked a unsuspecting flight attendant - sneaking up behind him and sucker punching the staffer aboard a flight from Mexico to Los Angeles

The shocking footage of an American Airlines passenger attacking a flight attendant shows him sneaking behind him and punching the employee aboard a flight between Mexico and Los Angeles.

The two seem to exchange words in an apparently tense encounter. The male attendant asked the traveler twice, “Are you threatening?”

Offscreen, the suspect seems to be grabbing at the attendant. This causes the employee to respond, ‘All right. That’s all.’ Before turning his back and walking away from him.

The man then attacks, and he turns back.

Gasps can be heard as the unruly passenger, dressed in an orange Hawaiian shirt, sprints toward the unaware staffer from behind.

The suspect then, while the attendant’s back is turned, strikes him in the back of the head with a closed fist. 

“Oh, my god!” a passenger can be heard shouting amid the resulting chaos, after the seemingly middle-aged suspect lands the underhanded blow. “What are you doing?” 

A separate video on social media shows airplane workers tying the suspect down to his chair after the outburst as awestruck passengers look on

Another video, posted on social media, shows plane workers tieing the suspect to his seat after an outburst. Awestruck passengers watch on

The worker attacked is seen grabbing a telephone to call authorities. As the attacker retreats, he appears to be admiring his work and returning to his chair.

A crew member is seen running to grab a pair restraints cuffs. 

Coincidentally, also on board the plane A producer for CBS San Diego affiliate KFMB-TV who was, who said passengers ‘helped restrain’ the suspect as staffers tied  him to his seat with flex cuffs, a zip-tie-like device used by airlines to detain passengers.

A separate video on social media shows the airplane workers engaging in this act, as awestruck passengers look on.

Los Angeles Airport Police then took the suspect from the plane after landing. The suspect has been taken into custody while an investigation is conducted. This could lead to him facing federal charges.

The suspect - who has not been named - was detained on suspicion of interfering with a flight crew. He faces federal charges if deemed responsible for the attack

Unnamed suspect was taken into custody on suspicion of interfering in flight crew. Federal charges could be brought against him if the incident is considered to have been his.

The identity of the suspect was not immediately available. However, American Airlines spokesmen stated that the man had been placed on permanent ban from flying and was then taken into police custody.

American Airlines does not condone violence towards its employees, spokesperson Derek Walls announced in Thursday’s statement. 

“The incident involved will prevent the individual from traveling with us again in the future. And we will cooperate closely with law enforcement to complete their investigations.”

The Association of Professional Flight Attendants (APFA), a union that represents more than 26,000 of flight attendants at American Airlines,  also responded publicly to the alleged assault.

In a statement released Thursday, the organization slammed the incident as ‘dangerous’ and ‘life-threatening,’ adding that it fit a pattern of similar attacks on airline staffers, potentially putting flight attendants at risk.

They added that they would do everything necessary to ensure that the accused is prosecuted to their full legal rights.

Julie Hendrick is the national president for the association of flight attendants. 

‘APFA supports all crew members affected by the incident and will make every effort to see that they are prosecuted to the maximum extent possible. 

The FAA reports that airlines reported over 3,000 incidents with unruly passengers between January 1 and now. Many of these were passengers refusing to adhere to a federal mandate to wear masks.

Although the FAA did not keep such records in previous years, one spokesperson said that it is safe to assume that this year’s figures are the best.

The FAA announced a “zero tolerance policy” against passengers who were disruptive in January. Since then, it has made public potential fines of up to $30,000 against passengers. It has also investigated over 400 cases. 

This is almost three times the total number of cases in a full year over the last decade according to FAA data.

Leaders of the major unions representing flight attendants praised the move, as they lobbied for the creation of the training programs following the terrorist attacks on Sept. 11. 2001. One day before the terrorists hijacked four aircraft, they assaulted many flight attendants and passengers.

Lyn Montgomery (president of the union representing Southwest Airlines flight attendants) stated that’since a flight attendant died first, we wanted us to ensure that we were able to protect ourselves against physical altercations on the plane’. It’s extremely valuable and urgently needed right now.

Sara Nelson (president of the Association of Flight Attendants) also advocated mandatory classes, but praised TSA for resuming voluntary ones due to the increase in flights-related confrontations.

She stated that this should be a clear message to the public about the seriousness of these incidents and the fact that the flight attendants were there to protect everyone on the plane.

Unruly passengers incidents have dropped since April, when the FAA banned airplanes from wearing face masks. Despite this, the FAA has initiated nearly 680 investigations into these assaults, which is far higher than normal.

This incident is under investigation by the FAA. The unidentified suspect remains at large.