The US Department of Transportation sued Southwest Airlines and fined Frontier Airlines for flight delays, seeking civil penalties against Southwest and imposing a $650,000 fine on Frontier, part of a broader crackdown on airline delay issues.

The DOT's moves come weeks after issuing a multi-million dollar fine against JetBlue.

Southwest is disappointed that DOT chose to file a lawsuit over two flights that occurred more than two years ago," a spokesperson for the airline said.

The US Department of Transportation (DOT) has sued Southwest Airlines for allegedly operating numerous "chronically delayed" flights in violation of federal laws prohibiting deceptive practices.

The U.S. Transportation Department is suing Southwest Airlines and has fined Frontier Airlines over "chronically" delayed flights, disrupting passengers' travel and plans.

US Government Sues Southwest Airlines and Fines Frontier for Chronically Delayed Flights The Transportation Department is stepping up enforcement of persistent flight delays with a lawsuit against ...

It serves like American Delta, United ... The Transportation Department is stepping up enforcement of persistent flight delays with a lawsuit against Southwest Airlines and a fine against Frontier ...

Airlines have a legal obligation to ensure that their flight schedules provide travelers with realistic departure and arrival times,” Transportation Secretary Pete Buttigieg said in a

Three U.S. senators said they want Frontier Airlines and Spirit Airlines to disclose whether they are manipulating seat fees by using customers' personal information to charge different fees to passengers on the same flight.

There’s been enough drama in the past year to knock U.S. airlines off their game. An Alaska Airlines blowout grounded dozens of planes. There was a failed JetBlue-Spirt merger and Spirit’s bankruptcy.

You're entitled to a refund if your flight is canceled for any reason, but other accommodations depend on the cause of the delay.

The US Department of Transportation is flexing its muscles against airlines who operate chronically late flights.