 The KC-10 Extender is an advanced tanker and cargo aircraft that has provided increased global mobility for the Air Force since 1981. Primarily used for air refueling, the KC-10's six tanks can carry more than 365,000 pounds of fuel. Though its primary mission is air refueling, the KC-10 can combine the tasks of a tanker and cargo aircraft and is capable of transporting ambulatory patients using patient support pallets during aeromedical evacuations.