Experts say police who dragged passenger had other options

United Airlines CEO Oscar Munoz waits to be interviewed in New York during a presentation of the carrier's new Polaris service a new business class product that will become available on trans Atlantic

Munoz said United would be examining its incentive programme for volunteers on overbooked planes.

In an Oval Office interview with the Wall Street Journal, Trump suggested that this kind of incident could be avoided in the future if carriers remove the upper limits on vouchers they offer passengers in return for giving up their seats.

Munoz, who leads United's parent company, apologized again to Kentucky physician David Dao, his family and the other passengers who witnessed him being taken off the flight. "The family of Dr. Dao wants the world to know that they are very appreciative of the outpouring of prayers, concern and support they have received". Sometimes it happens because the airline needs room for employees who are commuting to work on another flight - that's what happened Sunday on United Express.

On Wednesday, his lawyers filed an emergency request with an IL court to make sure that United preserves evidence such as videos, cockpit voice recordings, passenger and crew lists and other materials related to United Flight 3411.

"I won't go", Dao tells officers when they tell him he needs to leave the plane.

Dao's lawyer moved court on Wednesday seeking direction to the airline and the city of Chicago to preserve the evidence in the case.

Passenger Jayse Anspach told CNN that Dao and his wife initially agreed to take a later flight, but recanted upon learning that that flight wouldn't take off till Monday morning.

A bloodied and distressed Dao was caught on camera and the video was soon be shared over social media, prompting a massive backlash.

The airline's chief executive, Oscar Munoz, is insisting he will not resign.

The 300 officers on the Aviation Department's certified police force do not carry weapons (nor have they ever done so), but they have been asking to be armed since the force's founding 30 years ago, according to the Chicago Sun Times. When no one voluntarily came forward, United selected four passengers at random. He refused to leave.

That's when three Aviation Department police officers boarded the plane. Footage shot by other passengers showed Dao screaming and struggling as aviation officers removed him from his seat and pulled him down the aisle of the aircraft.

The U.S. Department of Transportation announced Tuesday that it is reviewing Sunday's events to see if United violated rules on overselling flights.

Since the video has gone viral and sparked controversy over how airlines treat their passengers, competitors Emirates and Royal Jordanian Airlines did not hesitate to throw major shade at United. The four top-ranking members of the Senate Commerce Committee asked the airline and Chicago airport officials for more information about what happened.