State-owned Caribbean Airlines (CAL) is being investigated by the United States Department of Transportation (DoT) for keeping passengers on the aircraft of an international flight for more than four hours.

The DoT said in a statement yesterday the four-and-a-half-hour delay occurred on August 15 on a CAL flight from New York's John F Kennedy International Airport to Piarco International in Port of Spain.

The DoT's Air Travel Consumer Report states that the only delay on a runway that violated the "Passenger's Bill of Rights" rules in August was CAL's flight.

The report states the rules against runway delays prohibit delays longer than four hours on international flights, and the three-hour rule for domestic routes.

The DoT said that since the new rules took effect, airlines can be fined US$27,500 for each passenger who is stranded on a plane.

CAL said the delay was caused by bad weather, and a number of other flights were also delayed. Corporate Communications head Clint Williams told the Express via telephone yesterday, he did not know how long the aircraft stayed on the tarmac.

"There was a tarmac delay of flight BW 421 on August 15, 2012 due to adverse weather conditions, (causing) airport congestion as a consequence of the bad weather and the aircraft having to return for refuelling after a lengthy initial period on the tarmac with other similarly-affected aircraft.

The total time of the delay exceeded four hours and as such, the US Department of Transport has requested verification that procedures that govern such a delay were followed.

Caribbean Airlines is complying with all requests for information from the DOT," he said in a follow-up statement.

Williams said this was standard procedure. He said he was not in a position to say when the report by the DoT would be completed.

He added that to his knowledge, issues passengers may have faced related to the delay had been dealt with by the airline's customer service staff members. —Carla Bridglal