The U.S. Department of Transportation (DOT) on Jan 15 announced a lawsuit against Southwest Airlines for illegally operating multiple chronically delayed flights and disrupting passengers’ travel. Operating chronically delayed flights is an unrealistic scheduling practice and can harm both passengers and fair competition across the airline industry. DOT’s lawsuit against Southwest seeks maximum civil penalties.

“As part of our commitment to supporting passenger rights and fairness in the market for airline travel, we are suing Southwest Airlines for disrupting passengers’ travel with unlawful chronic flight delays,” said U.S. Transportation Secretary Pete Buttigieg. “Airlines have a legal obligation to ensure that their flight schedules provide travelers with realistic departure and arrival times. Today’s action sends a message to all airlines that the Department is prepared to go to court in order to enforce passenger protections.”

DOT also took enforcement action against Frontier Airlines for operating multiple chronically delayed flights. DOT fined Frontier $650,000 in civil penalties with $325,000 to be paid to the U.S. Treasury and the remaining $325,000 to be suspended if the carrier does not operate any chronically delayed flights in the next three years.

Federal regulations prohibit airlines from promising flight schedules that do not reflect actual departure and arrival times. Unrealistic scheduling is considered an unfair, deceptive, and anticompetitive practice that disrupts passengers’ travel plans, denies them reliable scheduling information, and allows airlines to unfairly capture business from competitors by misleading consumers. Continuing to market a flight that has been chronically delayed for more than four consecutive months is one form of unrealistic scheduling. Under DOT rules, a flight is chronically delayed if it is flown at least 10 times a month and arrives more than 30 minutes late more than 50 percent of the time. Cancellations and diversions are included as delays within this calculation.

Earlier in January, the US DOT fined JetBlue Airways $2 million for “chronically delayed flights,” the first penalty of its kind. JetBlue operated four routes that were delayed at least 145 times from June 2022 through November 2023, the DOT said.