FedEx is facing a $417,500 fine from the US Department of Transportation Federal Aviation Administration (FAA) for allegedly using an unairworthy aircraft.

The FAA alleges FedEx failed to rebalance a horizontal stabiliser tab control surface on a Boeing 727 after repainting the part. FedEx allegedly failed to perform rebalancing requirements, which meant the aircraft was not airworthy, before operating it on at least 133 flights in that condition. It is classified as a major repair requiring rebalancing of the control surface in the Boeing 727 Structural Repair Manual.

FAA administrator, Michael Huerta says: “Safety depends on every operator paying close attention to every regulatory requirement. It’s also critical for operators to implement internal controls to ensure that they’re following all applicable protocols and regulations.”

FedEx has asked to meet with the FAA to discuss the case.