BookingAir

NEW YORK – Five flights were stuck on the tarmac for three hours or more in May, the first month under a new rule banning lengthy tarmac delays, the government said Thursday.

That compares with 35 three-hour delays in May 2009. United Airlines operated four of the five flights this May. One of those United flights stayed on the tarmac for almost five hours. All four of the United flights were bound for Denver on May 26 when severe thunderstorms and hail swept through Colorado. Denver International Airport had 30-to-60-minute delays on average that day and limited use of runways. The fifth was a Delta Air Lines flight from Atlanta to Dallas-Fort Worth on May 28, a day when thunderstorms popped up in Dallas.

Thunderstorms are one of the main causes of flight delays because they are difficult for airlines and airport officials to predict.

The Department of Transportation said it will be weeks or months before any fines may be levied against the airlines for violations. The maximum fine is $27,500 per passenger for airlines that do not return their planes to the terminal when they are delayed on the tarmac for three hours or more. There are exceptions for safety and security reasons.

Overall the on-time performance of U.S. carriers declined in May from the same month a year ago.

US Airways was the most successful major airline in getting travelers to their destinations on time, 85.3 percent of the time. Hawaiian and Alaska Airlines had the highest on-time rates overall in May.

Comair, which operates as Delta Connection, had the worst ranking in May with 67.1 percent of its flights arriving on-time.