(ABC 6 News) — The U.S. Department of Transportation says it is prepared to take airlines to court over flight delays. The agency has filed a lawsuit against Southwest, accusing the airline of illegally operating chronically delayed flights and disrupting passengers’ travel plans.

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.

American Eagle flight 5342 collided with a Black Hawk helicopter over the Potomac River, home to some of the country's most restricted airspace.

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

A Southwest ... to the U.S. Department of Treasury, but the other half can be waived if the airline doesn't operate any chronically delayed flights for the next three years. “Airlines have ...

The DOT is aiming to send a message to all airlines that it will go to court to enforce passenger protections.

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

The Department of Transportation defines a flight to be 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 are included as delays within this calculation.”

Authorities say an airline pilot who seemed to smell like alcohol was making pre-flight checks in the cockpit when police arrested him on a DUI charge.

A regional jet approach ing Reagan National Airport collided with a military helicopter over the Potomac River late Wednesday night, prompting a massive search and rescue operation.

Secretary of Transportation Sean Duffy promised to improve the nation's transportation infrastructure and systems after Vice President JD Vance swore in Duffy on Wednesday afternoon.

Figure skaters and coaches returning from the national championships were aboard the American Airlines flight that collided with a Black Hawk helicopter near Reagan National Airport on Wednesday, the U.