The McDonnell Douglas KC-10 Extender is an aircraft utilized by the United States Air Force (USAF) for both tanker and cargo operations.
This aircraft is a military variant of the three-engine DC-10 airliner and was developed through the Advanced Tanker Cargo Aircraft Program.
The KC-10 is equipped with specialized military equipment to fulfil its primary roles of aerial refuelling and transportation.
Its development was prompted by the need to supplement the KC-135 Stratotanker, following experiences in Southeast Asia and the Middle East.
The KC-10 was the second McDonnell Douglas transport aircraft to be selected by the Air Force, after the C-9. A total of 60 KC-10s were produced for the USAF.
Additionally, the Royal Netherlands Air Force operated two similar tankers, designated KDC-10, which were converted from DC-10s.
The KC-10 plays a crucial role in the mobilization of US military assets, participating in overseas operations far from home.
These aircraft have been utilized for airlift and aerial refuelling during several significant military operations, including the 1986 bombing of Libya (Operation Eldorado Canyon), the 1990-91 Gulf War with Iraq (Operations Desert Shield and Desert Storm), the NATO bombing of Yugoslavia (Operation Allied Force), War in Afghanistan (Operation Enduring Freedom), and Iraq War (Operations Iraqi Freedom and New Dawn).
The KC-10 Extender made its inaugural flight on 12 July 1980, with the first aerial refuelling sortie taking place in October of the same year.
The KC-10 design involved modifications from the DC-10-30CF design, with unnecessary airline features replaced by improved cargo-handling system and military avionics.
Despite these changes, the KC-10 retains 88% commonality with its commercial counterparts, providing it with greater access to the worldwide commercial support system.
Other alterations from the DC-10-30CF include the removal of most windows and lower cargo doors.
Early aircraft featured a distinctive light grey, white, and blue paint scheme, but a grey-green camouflage scheme was used on later tankers.
By the late 1990s, the paint scheme had been changed to a medium grey colour.
A jet aircraft can refuel from a grey three-engine tanker via a long boom located under the tanker’s aft fuselage.
The KC-10’s mixed refuelling system of hose-and-drogue and flying boom allows it to refuel the aircraft of the U.S. Air Force, U.S. Navy, U.S. Marine Corps, and allied forces.
The most notable changes were the addition of the McDonnell Douglas Advanced Aerial Refueling Boom and additional fuel tanks located in the baggage compartments below the main deck.
The extra tanks increase the KC-10’s fuel capacity to 356,000 lb (161,478 kg), nearly doubling the KC-135’s capacity.
The KC-10 has both a centreline refuelling boom and a drogue-and-hose system on the starboard side of the rear fuselage.
The centreline refuelling boom is unique in that it sports a control surface system at its aft end that differs from the V-tail design used on previous tankers.
The KC-10 boom operator is seated in the rear of the aircraft with a wide window for monitoring refuelling, rather than prone as in the KC-135.
The operator controls refuelling operations through a digital fly-by-wire system.
The refuelling boom can deliver fuel to a receiver at the maximum rate of 1,100 gallons (4,180 litres) per minute, while the centreline drogue system has a maximum fuel offload rate of 470 gallons (1,786 litres) per minute.
Unlike the KC-135, the KC-10’s hose-and-drogue system allows the refuelling of the Navy, Marine Corps, and most allied aircraft, all in one mission.
The final twenty KC-10s produced included wing-mounted pods for added refuelling locations.
The KC-10 can also carry a complement of 75 personnel with 146,000 lb (66,225 kg) of cargo, or 170,000 lb (77,110 kg) in an all-cargo configuration.
With that, it can transport those weights for an unrefuelled range of 4,400 miles (7,040 kms).
The KC-10 has a side cargo door for loading and unloading cargo, with handling equipment required to raise and lower loads to the cargo opening.
It can carry cargo and serve as a tanker on overseas missions. Variants KC-10A Initial military tanker version based on the DC-10-30CF. KDC-10 Conversion of DC-10-30CF aircraft to tanker/transport configuration. While an FMS program was run through McDonnell Douglas, the conversion of two aircraft was carried out by KLM. Omega Aerial Refuelling Services operates KDC-10-40. KC-10B After McDonnell Douglas did the KDC-10 conversion for the Royal Netherlands Air Force in 1992, they proposed a tanker/transport version of the MD-11CF which had the in-house designation KMD-11. MDC offered either conversion of second-hand aircraft (KMD-11) or newly built aircraft (KC-10B), the proposed KMD-11 offered 35,000 lbs more cargo capacity and 8,400 lbs more transferable fuel than the KC-10A. It was offered to the RNAF and Royal Saudi Air Force (RSAF) in the 1990s and the Royal Australian Air Force (RAAF) in the early 2000s. Specifications Crew 4 Capacity 170,000 lb of cargo,
25 pallets and 16 passengers, Or 17 pallets and 75 passengers Length 181 ft 7 in (55.35 m) Wingspan 165 ft 4.5 in (50.406 m) Height 58 ft 1 in (17.70 m) Wing area 3,958 sq ft (367.7 m2) Airfoil Root DSMA-496/-521/-522 Tip DSMA-519/-520 Empty weight 241,027 lb (109,328 kg) Gross weight 590,000 lb (267,619 kg) Max take-off weight 590,000 lb (267,619 kg) Fuel capacity 365,000 lb (165,561 kg) Powerplant 3 × General Electric F103 (GE CF6-50C2) turbofan engines, 52,500 lbf (234 kN) thrust each Performance Maximum speed 538 mph (866 km/h, 468 kn) Maximum speed Mach 0.89 Range 4,400 mi (7,100 km, 3,800 nmi) with a maximum passenger capacity; 3,800 nmi (7,038 km; 4,373 mi) with maximum cargo capacity. Ferry range 11,500 mi (18,500 km, 10,000 nmi) Service ceiling 42,000 ft (13,000 m) Rate of climb 6,870 ft/min (34.9 m/s). Sources Air Mobility Command Museum. McDonnell Douglas aircraft since 1920: Volume I-René J Francillon. Remembering an Unsung Giant, The Douglas C-133 Cargomaster and Its People-Cal Taylor. San Diego Air and Space Museum Archive. The National Museum of the U.S. Air Force.
