In addition to the three main DC-10 wing fuel tanks, the KC-10A has three large fuel tanks under the cargo floor, one under the forward lower cargo compartment, one in the center wing area and one under the rear compartment. Combined, the capacity of the six tanks carry more than 356,000 pounds (160,200 kilograms) of fuel - almost twice as much as the KC-135 Stratotanker.

Using either an advanced aerial refueling boom, or a hose and drogue centerline refueling system, the KC-10A can refuel a wide variety of U.S. and allied military aircraft within the same mission. The aircraft is equipped with lighting for night operations.

The KC-10A's boom operator controls refueling operations through a digital, fly-by wire system. Sitting in the rear of the aircraft, the operator can see the receiver aircraft through a wide window.

During boom refueling operations, fuel is transferred to the receiver at a maximum rate of 1,100 gallons (4,180 liters) per minute; the hose and drogue refueling maximum rate is 470 gallons (1,786 liters) per minute. The Automatic Load Alleviation System and Independent Disconnect System greatly enhances safety and facilitates air refueling. The KC-10A can be air-refueled by a KC-135 or another KC-10A to increase its delivery range.

The large cargo-loading door can accept most tactical air forces' fighter unit support equipment. Powered rollers and winches inside the cargo compartment permit moving heavy loads. The cargo compartment can accommodate loads ranging from 27 pallets to a mix of 17 pallets and 75 passengers.

The KC-10A's crew includes a pilot, co-pilot, flight engineer and boom operator. On certain missions, additional seats and bunks can be added to accommodate extra crew members.