“Federal rules mandate an airline cannot keep you in a plane on the tarmac more than three hours on a domestic flight, or four hours on an international flight, without returning the aircraft to the gate and letting passengers get off.

Under the U.S. Department of Transportation (DOT) "tarmac delay" rules, airlines are generally prohibited from keeping passengers on an aircraft for more than 3 hours for domestic flights and 4 hours for international flights without providing an opportunity to deplane. There are two main exceptions: if the pilot-in-command determines there is a safety or security risk in returning to the gate, or if Air Traffic Control advises that doing so would significantly disrupt airport operations. Additionally, the airline must provide food and water no later than two hours after the delay begins, and they must ensure that lavatories remain operable and the cabin temperature remains comfortable. If the delay exceeds 30 minutes, the airline is required to provide passengers with a status update, including the reason for the delay if known, and continue providing updates every 30 minutes thereafter.