During the same period that American Airlines struggled through a labor dispute with its pilots, the carrier's on-time performance dropped to 58% in September.
The nation's largest airlines arrived within 15 minutes of their scheduled time an average of 83% of the time, according to the latest numbers from the U.S. Department of Transportation. That's an improvement over the 79% on-time performance in August.
Fort Worth-based American Airlines had the worst on-time performance of all major airlines in September, according to the data released Thursday. The best on-time rate, 96%, was reported by Hawaiian Airlines.
The poor performance by American Airlines was no surprise considering that the airline canceled hundreds of flights and delayed others in September because of an increased number of calls for maintenance work filed by flight crews and a surge in pilots calling in sick, according to the airline.
The Allied Pilots Assn., the labor group that represents American Airlines pilots, has said its pilots have not been involved in any organized work slowdown.
American Airlines' parent company, AMR Corp., filed for bankruptcy protection in 2011, which allowed the carrier to toss out its contract with the pilots union. The union charged in September that the airline was only paying "lip service" to reaching an agreement with the pilots.
A spokesman for the union said Thursday that the pilots and AMR are in a "stalemate" over contract issues such as pay and outsourcing.
"In key areas, we still haven’t been able to close the gap with AMR management," union spokesman Gregg Overman said.
American Airlines cancels hundreds of flights through October
American Airlines says loose seats will be fixed by Saturday [Updated]
American Airlines CEO acknowledges rough few weeks
Follow Hugo Martin on Twitter at @hugomartin