Lockheed Martin Aeronautics has been awarded a contract for sustainment engineering services for the U.S. Air Force’s largest plane, the Pentagon said in a statement on Friday.

Accodring to a statement, Lockheed Martin Aeronautics has been awarded a $131,6 million contract for C‐5 military transport aircraft sustainment.

Work will be performed in Fort Worth, Texas; Marietta, Georgia; and Palmdale, California, and is expected to be completed Jan. 25, 2019.

The U.S. Air Force’s largest plane, the C-5, features several unique characteristics, including a nose cargo door and a kneeling nose gear, which allow for drive-on capability. While the Air Force began modernizing the aircraft in 1998, the fleet is rapidly approaching 50 years of service. 

As the Air Force’s largest and only strategic airlifter, the C-5 Galaxy can carry more cargo farther distances than any other aircraft. With a payload of six Mine Resistant Ambush Protected vehicles (MRAPs) or up to five helicopters, the C-5 can haul twice as much cargo as any other airlifter.

The age and unique characteristics of the airframe require routine, specialized maintenance.

The Air Force currently owns 52 Super Galaxy aircraft, which are only assigned to four units worldwide.