The DOT filed a lawsuit against Southwest Airlines, citing a pattern of chronic delays, as the government pushes for stricter accountability.

The Transportation Department is stepping up enforcement of persistent flight delays with a civil lawsuit against Southwest Airlines and a fine against Frontier Airlines.

The department's investigation found two Southwest Airline flights were delayed for five consecutive months in 2022. Both delayed flights resulted in more than 90% of disruptions between April and August that year.

President Joe Biden's administration on Wednesday sued Southwest Airlines , accusing the carrier of illegally operating multiple chronically delayed flights and disrupting passengers’ travel.

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 Department of Transportation said that two Southwest Airlines routes arrived late nearly 180 times in a five-month period in 2022.

Southwest Airlines Co. was sued by the U.S. Transportation Department for allegedly violating rules that require airlines to set and meet realistic flight schedules. The carrier was responsible for “unlawful chronic flight delays” that disrupted passengers’ travel plans,

Transportation Department sues Southwest Airlines, seeking over $2.1 million in penalties for chronically delayed flights.

The lawsuit alleges Southwest illegally operated chronically delayed flights and disrupted passengers' travel plans.

The Department of Transportation is suing the airline for what it characterized as months of "chronically delayed" flights — those that arrive at least 30 minutes late more than half the time.

Having assessed a first-of-its-kind fine for “chronic flight delays” against JetBlue Airways, federal regulators have now moved to penalize both Southwest Airlines and Frontier Airlines for similar infractions.