For a third straight month, Frontier Airlines was pinned to last place among U.S. carriers for on-time flights, and its rate of passenger complaints continued to ascend.

The latest Air Travel Consumer Report from the U.S. Department of Transportation’s Bureau of Transportation Statistics, covering September, shows the Denver-based “ultra low cost carrier” with a 71.7 percent on-time arrival rate for the month, by far the lowest among 12 major U.S. airlines. The average on-time rate in September was 85.5 percent.

Frontier also came in last in July and August.

As the DBJ’s Ed Sealover has reported, the airline has been grappling with staffing issues with Swissport, the contractor that provided ramp services for Frontier at its Denver International Aiport hub. Largely because of those issues, Frontier ended its contract with Swissport and has been transitioning its ramp services to a new contractor, Simplicity.

Frontier is the No. 3 airline at DIA by passenger counts.

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