Major US airlines grilled after passenger's violent removal

Major US airlines were grilled at a heated hearing on Tuesday, as lawmakers were pressing for better protection and service of aviation customers after a passenger was violently dragged off a United flight last month.

The US airline industry's overbooking and bumping policies have come under intense fire following the United incident which sparked global outrage, Xinhua news agency reported.

David Dao suffered a concussion and two broken teeth when being dragged off the flight since the airline needed to make room for crew members. He has reached a settlement with the airline.

United CEO Oscar Munoz on Tuesday apologised again to Dao before the Transportation and Infrastructure Committee with the House of Representatives.

"We had a horrible failure three weeks ago. It is not who we are," Munoz said. "We are here to talk about certain issues that won't happen again. We will work incredibly hard to earn -- not your business necessarily -- but your trust."

During the hearing, the United Airlines, Alaska Airlines, American Airlines and Southwest Airlines agreed to shorten their lengthy customer service contracts, which customers must agree to whenever they book a ticket.

United's contract is 46 pages with more than 37,000 words, while Alaska's is 67 pages and over 37,000 words long. The lengthy documents are also too complicated for the average person to comprehend.

Alaska agreed to reduce it to one page, while the other three airlines promised they will work to simplify their contracts.