During hours-long delays, American Airlines kept passengers waiting on board airplanes for the largest-ever fine.

It is the largest civil penalty the Department of Transportation has ever assessed, it said in a statement, for lengthy tarmac delays of 43 flights affecting more than 5,800 passengers. Between 2018 and 2021, the flights took place.

In August 2020, passengers on a plane in Texas sat aboard for six hours and three minutes. American Airlines’ 105-passenger flight landed after being diverted from Dallas-Fort Worth International Airport due to severe weather, with the Department of Transportation alleging that American did not have sufficient resources to properly handle several of these flights.

The maximum time that passengers can be held without getting off is three hours for domestic flights, and four hours for international flights. In addition, airlines are required to provide passengers with water and a snack as part of current regulations.

According to American Airlines, the delays were caused by “exceptional weather events” and represent only a very small percentage of the 7.7 million flights during that period.

Additionally, the company announced that it had invested in technology to improve flight handling in severe weather and reduce airport congestion.

Our customers and team members already benefit from these efforts, and we are always looking for ways to improve,” the airline said.

In addition to paying $2.05 million of the fine to the government, American has been credited with paying the other half in compensation for passengers.