American Airlines hit with record fine for keeping passengers on tarmac for hours

The U.S. Department of Transportation said Monday it is fining American Airlines $4.1 million for unlawfully keeping passengers stuck in planes on the tarmac for lengthy periods of time. 

American Airlines violated the DOT's rule prohibiting airlines for keeping passengers on planes for tarmac delays lasting three hours or more, the department said in a statement. During delays of this length, airlines are required to allow passengers to deplane. 

The fine is the largest civil penalty ever issued for tarmac delay violations, according to the agency. Passengers are owed more than $2.5 billion in refunds related to the delays.