No long US airline delays at close of summer

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 sat on the tarmac at New York's JFK Airport for four hours and 28 minutes before it took off for its destination, Trinidad and Tobago.

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.

Almost four in five flights were considered on-time in August, meaning they arrived within 15 minutes of their posted schedule. At a rate of 79.2 percent, U.S. airlines were just slightly less on-time than a year earlier but better than July's 76 percent on-time rate.