Airline on-time performance in August got better compared with a year ago, but Philadelphia's record slipped a little, winding up six spots from the bottom of the list, the U.S. Bureau of Transportation Statistics reported today. On-time arrivals and departures at PHL has been a little better than that most of the year.

The two largest carriers at the airport ended the month in a virtual tie for on-time arrivals, with Southwest at 75.8 percent and US Airways at 75.6 percent. Continental and its ExpressJet unit had the best records, 80.6 and 80.5 percent, according to a different government measure.

US Airways noted in a message to employees that its operational performance has improved steadily this year. For the first time since US Airways merged with America West four years ago, the airline finished in the top five among the older network carriers in the Department of Transportation's measures of on-time performance, rate of mishandled bag and customer complaints. In the most pleasant surprise, givens its dismal record in the past, US Airways was No. 3 for fewest mishandled bags in August.

Find millions of stats in the DOT's monthly air travel consumer report, and for the airport rankings, see the BTS report.

The monthly report prompted the Air Transport Association, the big airlines' trade group, to point out that the number of flights that were delayed by three hours or more keeps going down. The group is very much opposed to passenger-rights legislation that would mandate what airlines have to do for customers during long delays.

Delays have been declining primarily because airlines have been flying fewer flights. Fewer bags are being lost because fees for checked bags have reduced the number being checked. I've said what I think about passenger rights legislation, but let your representatives know if you think airline customer service has improved enough that the legislation isn't needed.

Clear, the Registered Traveler program designed to speed up airport security for frequent fliers who give up personal data on themselves, may be coming back to life. A California investor is looking into taking over if the previous operator's debt can be restructured. Read more here. 

Here is a really interesting case of what takes precdence: US Airways' right not to be regulated by state liquor laws on its airplanes, or state's right to deny an airline a liquor license because of public safety concerns. Last week, a U.S. District judge in Albuquerque said New Mexico has the right to deny a license to US Airways to protect its citizens. In particular, the state said the airline had served a man drinks after he was intoxicated, and he caused a highway accident that killed a family of five.

US Airways argued that the state did not have the power to regulate its practices in this case because the Airline Deregulation Act gave only the federal government that right. Airlines have successfully used that argument in the past to fend off efforts by states to regulate them, usually on consumer-rights issues. Read more about what happened in this case here.