Published: Oct 11, 2012 11:53 AM EDT
Updated: Oct 12, 2012 6:31 AM EDT

NEW YORK (AP) - The government says U.S. airlines closed the summer travel season without any lengthy tarmac delays in August, a sharp reversal from a month earlier.

There were more long delays in July on airport tarmacs than in the previous eight months combined.

In August one international flight was stuck for more than four hours. On Aug. 15, a Caribbean Airlines flight from New York's JFK Airport to Trinidad and Tobago sat on the tarmac for four hours and 28 minutes before it took off.

U.S. airlines are subject to huge fines if they keep passengers on a grounded plane for more than three hours. Violations start at four hours for international carriers at U.S. airports.

Major U.S. airlines had an average on-time rate of 79.2 percent in August.