Mild winter weather helped the nation's airlines post their best January on-time performance on record.
The government said Thursday that 83.7 percent of flights on the biggest airlines arrived on time in January.
That's up from 76.3 percent in January 2011, and the best January since 1995, when the government changed the way that delays are reported. But it was a dip from December's 84.4 percent rating.
The Department of Transportation said that fewer flights were canceled in January, too. About 1.5 percent of scheduled flights were scratched, down from 3.9 percent a year earlier.
And there were no reports of U.S. flights stuck on the tarmac for three hours or more _ or of international flights delayed for four hours or more. Airlines risk a hefty fine if planes sit on the runway that long.
Hawaiian Airlines reclaimed its traditional spot atop the on-time rankings, at 93.14 percent. AirTran Airways was next, followed by AirTran owner Southwest Airlines.
Frontier Airlines had the worst on-time rating, at 77.65 percent. Frontier's Lindsey Carpenter said weather at the airline's Denver hub was a problem. The other leading operators in Denver _ United, Southwest and SkyWest _ all had better arrival records there than Frontier.
Airlines benefited from fewer airport-snarling snowstorms. It was the fourth-warmest January on record, and snow cover in the lower 48 states was the third-lightest since 1967, according to government weather scientists.
Mild weather, however, can cause heartburn for airline bean-counters. When flights are canceled, airlines cram displaced passengers on to remaining planes. This results in the airline earning more money per seat because there are fewer empty seats.
This week Southwest's chief financial officer said the airline's revenue per seat per mile _ a closely watched measure of financial performance in the airline industry _ was lower this winter because fewer flights were canceled.
Whatever the weather, airlines seemed to be doing a better job handling baggage. The rate of mishandled bags fell 23 percent, to about three for every 1,000 passengers. American Eagle was the most likely to lose your bag, followed by two other regional carriers, ExpressJet and SkyWest.
The Transportation Department said it received 708 complaints about U.S. airlines in January, an increase of 3 percent compared with a year earlier. However, most passengers don't bother to file paperwork with the government, so it's hard to draw conclusions from such small numbers.
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