On-Time Flight Rates Improve Only Slightly (Washington, D.C.) -- U.S. airlines are still struggling to land flights on time. August figures showed only a slight improvement from July numbers, which were among the worst monthly figures since data collection began in 1995. More than 71-percent of domestic flights arrived on time in August, the U.S. Transportation Department says. The August on-time rate is still far below the 76-point-eight percent rate posed in August 2006. Atlantic Southeast Airlines had the worst on-time record in August, followed by United Airlines and Alaska Airlines. Aloha Airlines 97-percent on-time rate was the best in August.