In a first, the US fines an airline for flight delays. Customers could get a cut.

• The US Department of Transportation hit JetBlue with a $2 million fine for delayed flights.
• The DOT said the airline's unrealistic flight schedules were deceptive and anticompetitive.
• Half of the $2 million fine is set to go toward compensating JetBlue customers.

The Department of Transportation said on Friday that it was fining JetBlue Airways $2 million for operating chronically delayed flights.

It said the first-of-its-kind penalty followed an investigation that found that JetBlue promised its customers unrealistic schedules that didn't reflect actual flight departure and arrival times on four routes between its bases in New York and Florida and destinations in North Carolina and Connecticut. The agency described this as a deceptive and anticompetitive way to generate business.

The department said it was looking into similar practices by other carriers but didn't go into specifics.

In recent years, many airlines have padded their flight schedules with additional time to help their crews absorb weather, mechanical, air-traffic-control, or airport-congestion issues and still arrive on time.

The department said that half the $2 million would be paid in cash to the US Treasury and the other half would be set aside as compensation for JetBlue passengers harmed by future delayed flights. It said compensation and vouchers for each affected passenger must be valued at at least $75.

The data provider Cirium said that just 74.5% of JetBlue flights managed to stay on schedule last year, putting it behind all its major US competitors. Only Frontier had a lower on-time percentage.

JetBlue argued that the government should upgrade the nation's air-traffic-control system to increase reliability for all flights.

"We appreciate how important it is to our customers to arrive to their destinations on-time and work very hard to operate our flights as scheduled," the airline said. "While we've reached a settlement to resolve this matter regarding four flights in 2022 and 2023, we believe accountability for reliable air travel equally lies with the US government, which operates our nation's air traffic control system."

The US is experiencing a shortage of air-traffic controllers, which has limited airports' ability to handle high traffic and resulted in heavy delays during holiday travel and summer vacations. United Airlines recently said that 343,000 of its customers were harmed in November by delays caused by air-traffic-controller shortages at its hub at Newark Liberty International Airport.

Shares of JetBlue fell by about 2% in trading on Friday morning.