The Federal Aviation Administration (FAA) has recommended a $4 million civil penalty against United Parcel Service (NYSE:UPS) alleging that it did not adhere to a consent agreement in which UPS was to inspect its airplane fleet and compare completed repairs with maintenance records, the FAA announced.

In its statement, the FAA asserts that the Louisville, Ky.-based UPS neglected to follow established structural repair procedures on four of its planes. The aircraft in question were used on more than 400 flights between 2008 and 2009, even though they did not meet the FAA's compliance regulations.

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

UPS has 30 days after it receives the FAA's letter, including the proposed $4 million penalty, to respond.

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