Delta Air Lines Inc., US Airways and Southwest improved their on-time performances in September, according to the U.S. Bureau of Transportation Statistics.

Atlanta-based Delta ranked ninth among U.S. carriers in on-time performance, making scheduled arrivals 84 percent of the time.

The airline ranked 12th for September 2007 in the Air Travel Consumer Report, which tracks data for the top 20 U.S. carriers.

Southwest results improved slightly to 89 percent of flights being on-time compared to 85 percent last year. Its ranking rose one slot to fifth.

US Airways improved its ranking to 10th from 14th, with an on-time rate of 84 percent compared to 80 percent the previous September.

Birmingham International Airport reported 84.7 percent of on-time flights in September compared to 83 percent last year and 88 percent of departures on-time versus 87 percent last year.