Airline on-time performance falls, tarmac delays up in June

— -- U.S. airlines' on-time performance fell in June as more summer travelers took to the sky.

The nation's 19 largest airlines reported an overall on-time arrival rate of 76.1% in June, down from May's 80.5% but better than 70.8% in June 2008, according to a monthly report by the Department of Transportation's Bureau of Transportation Statistics Tuesday. The airlines canceled 1.5% of their scheduled domestic flights, up from 0.9% in May.

The industry's on-time rate has been improving steadily in recent months as airlines cut back on flights, which eases airport congestion. But airports get more crowded in the summer as air travel typically starts to climb in June from earlier months.

Among the major carriers, Alaska Airlines was the best performer, with 84.5% of flights arriving on time. Frontier was the worst, with 68%.

The DOT says 7.7% of all flights in June were delayed by aviation system issues. Other factors cited include: late-arriving aircraft (7.5%); factors within the airline's control, such as maintenance or crew problems (5.9%); extreme weather (0.8%); and security reasons (0.04%).

In reporting their data, airlines can cite these factors for delays, but many of the cited reasons are also often triggered by bad weather. The DOTs' closer analysis showed that 43% of all delays were caused by bad weather.

It was a bad month for travelers caught in tarmac delays. The industry reported 172 flights with three hours or more of wait time before departing, up from 25 in May. JetBlue and ExpressJet each had a flight that had tarmac delays of five hours or more at New York John F. Kennedy and New York LaGuardia, respectively.

Other findings:

•Most-delayed flights.Pinnacle Airlines' flight 2330 from Minneapolis/St. Paul to Fort Wayne, Ind., was the most consistently late flight. It was never on time in June. Among major carriers, Northwest's flight 1554 from West Palm Beach, Fla. to Boston was the most chronically delayed, late 96.3% of the time.