WASHINGTON D.C. – The U.S. Department of Transportation’s Federal Aviation Administration has proposed a $4 million civil penalty against United Parcel Service of Louisville, Ky., for allegedly maintaining four cargo aircraft improperly and then operating them when they were not in compliance with Federal Aviation Regulations.

The FAA alleges that UPS failed to follow FAA-approved procedures for making structural repairs to two DC-8 aircraft and two MD-11 aircraft. UPS operated the four planes on more than 400 flights between October 2008 and June 2009.

“The aviation industry knows that we take safety very seriously,” said U.S. Transportation Secretary Ray LaHood. “Air carriers must comply with federal regulations to ensure aircraft are maintained to the highest level of safety.”

These violations stem from UPS’s failure to fully comply with the terms of a consent agreement in which the carrier agreed to inspect all aircraft in its fleet and compare actual repairs with maintenance records. This would have ensured the four aircraft were in compliance with the regulations.

“No aircraft should leave the ground until the operator has made all necessary repairs, and made them according to the correct procedures,” said FAA Administrator Michael Huerta.

UPS has 30 days from the receipt of the FAA’s civil penalty letter to respond to the agency.