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.

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.

A lawsuit filed against Southwest alleges the airline operated multiple “chronically delayed” flights affecting thousands of passengers.

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 Transportation Department is taking legal action against Southwest, alleging the airline illegally operated persistently delayed flights and disrupted passengers' travel plans.

According to Sharon Petersen, the CEO of AirlineRatings.com, while Air New Zealand came in first place for the world’s safest full-service airline, it was a pretty close race. There was only a 1.5-point difference between that airline and Qantas, which both “uphold the highest safety standards and pilot training,” as noted by Petersen.

The Department of Transportation filed a lawsuit against Southwest Airlines for allegedly operating chronically delayed flights in 2022. It also fined Frontier Airlines for chronic delays.

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

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