According to FlightStats, United Airlines in August had the highest cancellation rate among major U.S. carriers at 1.40 percent

of scheduled flights. It was followed by JetBlue Airways (1.28 percent). Continental Airlines' cancellation rate again was lowest among major carriers at 0.17 percent. Among regional operators, US Airways subsidiary Piedmont Airlines had the highest cancellation rate at 4.35 percent, followed by Delta Air Lines subsidiary Comair (4.03 percent), according to FlightStats.