KC-10 Extender
KC-10 Extender
Description
Role	Mid-air refueling
Crew	3-6 (pilot, copilot, flight engineer + 3 refueling crew)
Dimensions
Length	181 ft 7 in	55.35 m
Wingspan	165 ft 4 in	50.4 m
Height	58 ft 1 in	17.7 m
Wing area	3,958 ft²	367.7 m²
Weights
Empty	241,027 lb	109,328 kg
Loaded
Maximum take-off	590,000 lb	267,620 kg
Powerplant
Engines	3 F103/General Electric CF6-50C2 turbofans
Thrust	52,500 lbf (static)	234 kN
Performance
Maximum speed	610 mph	982 km/h
Combat range	4,370 mi	7,032 km
Ferry range	11,500 mi	18,507 km
Service ceiling	33,400 ft	10,180 m
Rate of climb	6,870 ft/min	34.89 m/s
Armament
Guns	None
Bombs	None

The KC-10 Extender is a tanker aircraft in service with the US Air Force. Though the 59 Extenders currently in service are greatly outnumbered by the venerable KC-135 Stratotanker, the KC-10 has a significantly larger fuel capacity.

Beginning with the Vietnam War doubts began to be raised about the ability of the 700+ strong KC-135 fleet to meet the needs of the United States’ global commitments. The air-refueling fleet was deployed to South-East Asia in support of tactical aircraft and strategic bombers, while maintaining the US based support of the nuclear bomber fleet. As a result studies began into the feasibility of acquiring an air-to-air tanker with a greater capability of the KC-135 fleet, but did not progress well due to lack of funding.

The Yom Kippur War in 1973 demonstrated the necessity of adequate air-refueling capabilities. Denied landing rights in Europe, USAF C-5 Galaxys were forced to carry a fraction of their maximum payload on direct flights from the continental United States to Israel. As a result C-5 crews were soon trained in aerial-refueling and the Department of Defense concluded that a more advanced tanker was needed.

In 1975, under the “Advance Tanker/Cargo Aircraft” programme, four aircraft were evaluated, the C-5 itself, the Boeing 747 (which lost out to the C-5 in a previous military contract), the McDonnell Douglas DC-10 and Lockheed L-1011. Donald Rumsfeld, in his first posting to the Pentagon, selected the KC-10 in 1976.

Conversion to the KC-10 involved only minor modifications to the DC-10, the largest of which was the addition of a boom control station in the rear of the fuselage and extra fuel tanks under the main deck. First deliveries to the Strategic Air Command (then in control of AAR assets) commenced in 1981.

In the AAR role the KC-10 has been operated largely in the same way as the RAF’s Tristar (L-1011s,) i.e. the strategic refueling of large number of tactical aircraft on ferry flights and the refueling of other strategic transport aircraft. Conversely, the KC-135 and RAF VC-10 fleets have operated largely in the in-theatre “tactical” role. Excellent examples of the KC-10s strategic role are,

• Operation Desert Shield
  The KC-10 fleet facilitated the deployment of tactical, strategic and transport aircraft to Saudi Arabia.
• Operation Eldorado Canyon
  Faced with refusals of basing and over flight rights from continental European countries the US was forced to use UK based F-111 'Aardvarks' in their 1986 air-strikes against Libya. The KC-10s allowed 29 F-111s to reach their targets.

The Royal Netherlands Air Force operates two "KDC-10s" in the aerial refueling role and is acquiring an additional aircraft to serve in the strategic transport role.

The KC-10 is currently the world's longest-ranged production aircraft, and will continue to hold that record past the introduction of the Boeing 777-200LR, though future 777 variants may range further.