The DOT also said that the airlines had a significantly higher domestic flight cancellation rate and a higher mishandled baggage rate in the final month of 2008 compared to November. Even complaints about airline service were up in December compared to November.
Still, the DOT said the airlines did a better job in all four categories in December compared the same month in 2007. The airlines overall had reported month-to-month improvement in on-time performance from July to October, but slipped in November compared to October and in December compared to November.
As airlines have cut capacity and made other changes, generally they have been able to cut delays and do a better job handling bags. But some have struggled compared to their peers.
Regional carrier Comair, a unit of Delta Air Lines Inc., had the worst on-time performance in December, while Hawaiian Airlines had the best on-time performance in the month.
The DOT's Bureau of Transportation Statistics said the 19 carriers reporting on-time performance recorded an overall on-time arrival rate of 65.3 percent, up from December 2007's 64.3 percent but down from November 2008's 83.3 percent. In December, 45.4 percent of late flights were delayed by weather. Also in December, the carriers filing on-time performance data reported that 10.6 percent of their flights were delayed by aviation system delays, 11.1 percent by late-arriving aircraft and 7.7 percent by factors within the airline's control such as maintenance or crew problems.
There was heavy snow in parts of the country around Christmas and in the final days of December. Some of the aviation issues in general involved the national aviation system. According to the DOT, delays and cancellations attributable to the national aviation system refer to a broad set of conditions, including non-extreme weather conditions, airport operations, heavy traffic volume and air traffic control.
In December, the carriers canceled 3.3 percent of their scheduled domestic flights, down from the 3.5 percent cancellation rate of December 2007 but higher than the 0.8 percent rate posted in November 2008.
The airlines overall posted a mishandled baggage rate of 6.96 reports per 1,000 passengers in December, an improvement over December 2007's rate of 9.05 but higher than November 2008's 3.75 rate.
The DOT said that in December it received 700 complaints about airline service from consumers, down 17.8 percent from the 852 complaints filed in December 2007 but 31.6 percent more than the total of 532 received in November 2008.
Erlanger, Ky.-based Comair had the lowest on-time arrival rate in December, at 55.1 percent. The most frequently delayed flight in the month was SkyWest Airlines flight 4669 from Atlanta to San Antonio, Texas, which was late 94.1 percent of the time.
Alaska Airlines, a unit of Seattle-based Alaska Air Group Inc., had the second lowest on-time arrival rate in December, at 58.4 percent, while American Eagle, a unit of Fort Worth, Texas-based AMR Corp., which also operates American Airlines, had the third lowest on-time arrival rate in December, at 59.3 percent.
Hawaiian topped the list with a December on-time arrival rate of 79.6 percent, while US Airways Group Inc. had the second-highest on-time arrival rate in the month, at 72.1 percent, and American Airlines had the third-highest on-time arrival rate, at 69.9 percent.
Among legacy carriers, US Airways' on-time performance was highest in December. The five legacy carriers - Delta, American, United Airlines, Continental Airlines and US Airways - are those that had a large presence in multiple regions before deregulation in 1978. Delta acquired Northwest Airlines, which also had been a legacy carrier, on Oct. 29. For discount carriers, Dallas-based Southwest Airlines Co. had the best on-time arrival rate in December, at 67.3 percent, good for fifth best overall.
For all of 2008, American Airlines was at the bottom among the 19 reporting airlines in on-time performance, while Hawaiian was at the top.
Overall, the 19 carriers reporting on-time performance recorded an overall on-time arrival rate of 76 percent for January through December 2008, up from 2007's 73.4 percent rate.
U.S. airlines lost billions of dollars in 2008 despite the rapid decline in fuel prices in the last few months of the year. Weakening demand for seats amid the global financial crisis was a key reason for the losses.