For yet another month, the nation’s 18 largest airlines improved their on-time performance, as they continued to operate networks with less capacity than at this time a year ago.

The carriers reported an overall on-time arrival rate of 85.3% in April, compared with 79.1% for the same month in 2009, according to the Transportation Department’s Bureau of Transportation Statistics.

April’s on-time rate also edged the carrier’s 80% rate for March, the BTS reported.

On-time arrival performance in the first four months of 2010 was 79.8%, the third-best first quarter in the 16 years the government has tallied the data. The only two two years with better on-time performance in the first four months were 2002 and 2003.

It also was the second-best April for on-time performance, after April 2003. The average for the month over the past decade and a half has been about 79.9%.

Again, Hawaiian reported the best monthly on-time performance for April, 93.5%, followed by Alaska’s 90.9% and US Airways’ 88.6%.
Bringing up the rear were American Eagle and Comair, both with 82.3%. American did slightly better with a rate of 83.2%.

In April, the BTS reported just one flight with a tarmac delay of four hours or more and four flights with delays of three hours or more.
There were 25 tarmac-delay times of three hours or more in March, the BTS reported.

The DOT is considering new rules that would require more airlines to report delay information in greater detail to get a truer picture of the number and impact of the delays.

"The data do not … provide a complete picture of tarmac delays, as the reporting carriers only submit data concerning their scheduled domestic flights as a function of their being required to report on-time performance data," the DOT said earlier this month in releasing details of its proposal and asking for industry comment.

Meanwhile, new DOT rules that took effect April 29 require airlines to allow passengers to get off planes that have been stuck on the tarmac for three hours. Carriers face fines up to $27,500 per passenger per flight for violations.

Airline executives say they will cancel more flights to avoid the heavy fines. In April, the carriers canceled 0.7% of their scheduled domestic flights, less than half of the 1.5% of flights they cancelled in both April 2009 and March 2010.