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

Southwest Airlines is being sued and Frontier Airlines fined over chronic flight delays by the Department of Transportation, the DOT announced Wednesday. Why it matters: Wednesday's announcement by the outgoing Biden administration's Transportation Secretary,

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

Spirit Airlines announced it will cut 200 jobs in an effort to reduce costs after filing for bankruptcy in November.

While the initial fine was $325,000, the DOT warned that if Frontier Airlines continues to chronically delay flights, the penalty will double.

Southwest Airlines was sued in federal court by the Department of Transportation, while Frontier was hit with a $650,000 fine.

Frontier Airlines recently announced new benefits for members of its loyalty program, including a fast-track offer that helps travelers achieve Elite Platinum status with as little as 20,000 points.

The lawsuit filed in California alleges that Southwest illegally operated chronically delayed flights and disrupted passengers’ travel plans.

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.

Southwest Airlines stock fell Thursday after the Department of Transportation sued the airline over a pair of "chronically delayed flights."

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

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