The U.S. Department of Transportation on Friday announced a $2 million fine against JetBlue for “operating multiple chronically delayed flights.”

The announcement marks the first time the agency has fined an airline for chronic flight delays – “a prohibited unrealistic scheduling practice which can harm both passengers and fair competition across the airline industry,” the DOT said in the statement.

The agency says half of the $2 million fine is going to compensate JetBlue customers “affected by the airline’s chronic delays or any future disruptions caused by JetBlue within the next year.” According to the announcement, the DOT has ongoing investigations into the other airlines for unrealistic flight schedules. JetBlue must pay half of the penalty – $1 million in cash – directly to the U.S. Treasury.

“Illegal chronic flight delays make flying unreliable for travelers. Today’s action puts the airline industry on notice that we expect their flight schedules to reflect reality,” U.S. Transportation Secretary Pete Buttigieg said in the announcement. “The department will enforce the law against airlines with chronic delays or unrealistic scheduling practices in order to protect healthy competition and ensure passengers are treated fairly.”

According to the Department of Transportation, the agency’s investigation uncovered that JetBlue operated four chronically delayed flights at least 145 times between June 2022 through November 2023. Each flight was chronically delayed for five straight months in a row – or more.

The DOT says despite its warning, JetBlue continued to operate three more chronically delayed flights between Fort Lauderdale and Orlando, Fla. and JFK, and between Fort Lauderdale, Fla. and Windsor Locks, Conn.

The Bureau of Transportation Statistics estimates, based off of data submitted to DOT by JetBlue, that the airline was responsible for over 70 percent of the disruptions for the four chronically delayed flights.