A United Airlines electronic departure board is pictured inside the terminal at Newark International Airport in New Jersey
A United Airlines electronic departure board is pictured inside the terminal at Newark International Airport in New Jersey, July 22, 2014. Reuters/Stringer

A United Airlines flight was forced to divert from its original flight plan after two passengers fought over personal space and the use of reclining seats.

The fight between two passengers, a male and a female, both aged 48, aboard United Airlines Flight 1462 began when one used a Knee Defender device, an anti-seat reclining lock. The two plastic hooks device attaches to a tray table and jams the reclining mechanism of the seat in front.

The flight was bound to Denver from Newark, New Jersey.

Police authorities called to the scene when the airline decided to divert to Chicago's O'Hare International Airport said the commotion between the two passengers started when the male, because he was on his laptop, used the Knee Defender to stop the woman in front of him from reclining.

A flight attendant was called to mediate and asked the male traveler to remove the anti-seat reclining lock. He refused.

Both passengers were seated in United's Economy Plus section, which has four more inches of legroom than the rest of coach.

Within seconds, the woman in front of him stood up, turned around and threw a cup of water at him. That's the time the pilot of United Airlines Flight 1462 decided to divert the plane and make an unscheduled landing in Chicago.

Officers from the Chicago Police as well as from the Transportation Security Administration spoke to both passengers. They ruled the altercation was a "customer service issue."

The passengers, whom the TSA refused to identify, were directed to disembark the plane.

The plane pushed through with its flight, albeit one hour and 38 minutes behind schedule, but without the two feuding passengers.

Ira Goldman, inventor of the Knee Defender, told ABC News the man used the device for exactly a different reason as to how it was supposed to be used.

He said Knee Defenders were created to "prevent something from moving and hitting you."

"It starts the conversation before there's a problem," he said. "This has been on a market for 11 years next month. [It's] never happened before."

Apparently, part of the instructions that come before using the Knee Defender says, "Be courteous. Do not hog space. Listen to the flight crew."

"Apparently that is not what happened here," he said.

United Airlines said the device, as with all major U.S. airlines, is prohibited from all its flights.

YouTube/ TomoNews US