The number of jetliners delayed on the tarmac for at least three hours skyrocketed during June, a U.S. Department of Transportation report out Monday shows.
In June, 462 aircraft sat for at least three hours awaiting takeoff after leaving the gate, more than tripling the 137 such delays during May. DOT says it's the highest monthly number since at least 2000.
The report, which examines the performance of big U.S. airlines, is the latest indication of air travelers' summer discomfort. Many big U.S. airlines have reported over the past week that they operated July flights fuller than ever.
Through the end of June, 925 airliners this year waited at least three hours on tarmacs. If the trend continues, airlines this year could break the previous full-year record of 1,617 tarmac delays of three-hours-plus reached in 2000.
Passengers who flew out of New York's John F. Kennedy Airport were the most likely to get stuck on a runway. JFK had about a third of the month's three-hour-plus taxi times.
JFK's two biggest airlines, JetBlue and Delta, had the highest rates of flights with ultra-long taxi times. In June, JetBlue had 38 planes stuck for three-hours-plus per 10,000 departures, and Delta had 17, according to a USA TODAY analysis of DOT data.
JetBlue blames the high rate on air-traffic congestion, particularly around New York, and bad weather. Because JFK is JetBlue's home airport, airline spokeswoman Jenny Dervin says, "Anything that happens at JFK is going to affect our system." About two-thirds of JetBlue's 550 daily flights involve JFK.
Dervin said the airline paid an undisclosed sum under the carrier's bill of rights for the June delays.
The congested sky over New York -- a patch that's just 20 miles by 20 miles sees more than a million flights a year -- created troubles at JFK's neighboring airports, too. Newark, with 72 tarmac waits over three hours in June, and LaGuardia, with 39.
The DOT report shows that a Newark-to-Denver Continental Airlines flight waited 383 minutes -- more than six hours -- for takeoff on June 8, recording the longest tarmac wait for the month.
Airlines operated, on average, 68% of flights on time in June, making it the second-worst June since the government started tracking the data in 1995.