Military Transport Planes
Overview
The KC-10 Extender is a three-engine aerial refueling tanker and cargo aircraft that McDonnell Douglas built for the U.S. Air Force from the DC-10-30CF airliner. It could refuel receivers by flying boom or hose and drogue and haul heavy cargo on the same mission, and 60 were delivered to the Air Force before the type retired in 2024.
Specifications
Units
- Engine
- 3 × F103/General Electric CF6-50C2
- Engine type
- Turbofan
- Thrust
- 3 × 52,500 lbf · 234 kN
- Avionics
- Rockwell Collins
- Wing tips
- No winglets
- Seats
- 4
- Crew
- —
- Cabin width
- 18 ft 8 in · 5.70 m
- Cabin height
- 8 ft 2 in · 2.50 m
- Cabin length
- 120 ft 9 in · 36.80 m
- Exterior length
- 181 ft 7 in · 55.35 m
- Tail height
- 58 ft 1 in · 17.70 m
- Fuselage diameter
- 19 ft 9 in · 6.02 m
- Wing span
- 165 ft 5 in · 50.41 m
- Baggage volume
- 16,845 ft³ · 477.0 m³
- Gross weight
- —
- Empty weight
- 241,027 lb · 109,328 kg
- Max takeoff weight
- 593,000 lb · 269,000 kg
- Max landing weight
- 416,500 lb · 189,000 kg
- Max payload
- 169,500 lb · 77,000 kg
- Fuel capacity
- 42,700 gal · 161,700 L · 129,400 kg (Jet A)
- Maximum speed
- 468 kt · 539 mph · 867 km/h
- Cruise speed
- —
- Approach speed
- 149 kt · 171 mph · 276 km/h
- Range
- 3,800 nm · 4,370 mi · 7,040 km
- Fuel burn
- —
- Ceiling
- 42,000 ft · 12,800 m
- Rate of climb
- 6,870 ft/min · 35 m/s
- Takeoff distance
- 9,850 ft · 3,000 m
- Landing distance
- 5,900 ft · 1,800 m
Gallery
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Operational Context
Table of Contents
What the KC-10 Extender was
The KC-10 Extender was the U.S. Air Force’s big tanker and cargo aircraft, a military DC-10-30 built to refuel other aircraft and carry freight on the same flight. The Air Force bought 60 of them, and the last one flew out of Travis Air Force Base, California, on September 26, 2024.
It was one of the few jets that could refuel receivers in the air and haul heavy cargo and passengers over long distances in the same mission.
Why the Air Force wanted it
After Vietnam the Air Force wanted a tanker with more range and capacity than the KC-135. The 1973 Yom Kippur War, and the airlift effort of Operation Nickel Grass, had also exposed mobility shortfalls.
In 1975 the service evaluated the Boeing 747, the Lockheed C-5 and the McDonnell Douglas DC-10. The DC-10 won in December 1977, mainly because it could use shorter runways.
The initial order was for 12 aircraft and grew to 60. The KC-10 shares about 88% of its design with the civilian DC-10.
Development and service history
The first KC-10 flew on July 12, 1980, and the first aerial refueling sortie followed in October 1980. The first aircraft was delivered to Strategic Air Command in March 1981, and the 60th and last was delivered on November 29, 1988.
Over the years the fleet was based mainly at Travis Air Force Base in California and McGuire Air Force Base in New Jersey, with Air Force Reserve associate units flying alongside the active-duty crews.
The type’s first combat use came in 1986, when KC-10s and KC-135s helped 29 F-111s reach Libya during Operation El Dorado Canyon after European nations refused basing and overflight.
In Operations Desert Shield and Desert Storm, the KC-10 and KC-135 together flew about 51,700 refueling operations and delivered 125 million gallons of fuel.
After September 11, 2001, KC-10s flew more than 350 missions under Operation Noble Eagle and more than 1,390 missions in Operations Enduring Freedom and Iraqi Freedom combined. In 2021 they supported Operation Allies Refuge, the evacuation from Afghanistan.
On September 17, 1987, KC-10A 82-0190 was destroyed by an explosion and fire on the ground at Barksdale Air Force Base, and one ground crew member died. It is the type’s best-known loss.
How the KC-10 refueled other aircraft
The KC-10 carried two refueling systems. A flying boom, operated by a boom operator through a digital fly-by-wire system, could pass fuel at up to 1,100 gallons (4,200 L) a minute.
A centerline hose and drogue on the starboard rear fuselage could pass up to 470 gallons (1,800 L) a minute. The last 20 aircraft also gained wing-mounted hose and drogue pods.
That mix mattered because Air Force receivers use the boom, while Navy, Marine and many allied aircraft use a probe and drogue. One tanker could serve both on the same sortie. For the wider picture, see our guide to how airplanes refuel in the air.
Cargo and the crew
The KC-10 could carry 75 personnel with 146,000 lb (66,000 kg) of cargo, or up to 170,000 lb (77,000 kg) in an all-cargo layout. It could also refuel while carrying that cargo.
Four crew flew it: an aircraft commander, a copilot, a flight engineer and a boom operator.
Explaining the numbers
The full specification table for the aircraft is on this page. A few figures need context.
The first is range. The panel’s range figure applies with a full cargo load and no refueling. The ferry range, flown without that load, is much longer at 11,500 miles (18,500 km).
The second is speed. The panel lists the top speed in knots, which Wikipedia’s specification block gives as Mach 0.89.
The third is weight. Published maximum takeoff weights for the KC-10 differ by a few thousand pounds between sources, so treat any single figure as approximate.
KC-10 vs KC-135
The KC-10 was larger than the Boeing KC-135 Stratotanker and could move far more fuel and cargo. It also moved cargo and passengers on the same flight.
The KC-135 outlasted it. According to coverage of the farewell, after the KC-10 left, the tanker fleet was nearly 80 KC-46s and over 370 KC-135s.
Retirement and what replaced it
The first KC-10 to retire, tail 86-0036, went to the 309th Aerospace Maintenance and Regeneration Group at Davis-Monthan Air Force Base, Arizona, in July 2020, as squadrons moved to the KC-46 Pegasus.
In January 2023 the Air Force announced that all KC-10s would retire by September 30, 2024. The last combat sortie was on October 5, 2023.
The final aircraft, 79-1948, took off from Travis on September 26, 2024, for storage at Davis-Monthan after a farewell ceremony. A few survive in museums, including the first one built, 79-0433, at the Air Mobility Command Museum at Dover Air Force Base.
Not every KC-10 is gone from the sky. The Royal Netherlands Air Force flew two KDC-10 conversions from 1995 to 2021, and the commercial tanker company Omega Aerial Refueling Services bought them. We cover a former Air Force KC-10 returning to flight in this article, and the wider field in our ranking of every aerial refueling tanker.
Frequently Asked Questions
What is the KC-10 used for?
The KC-10 Extender refueled other aircraft in flight and carried cargo and passengers. It could do both on the same mission, which is why the Air Force used it for long-range deployments.
Is the KC-10 still flying?
Not with the U.S. Air Force. The last Air Force KC-10 flew to storage at Davis-Monthan on September 26, 2024. Former Dutch KDC-10 tankers are operated commercially by Omega Aerial Refueling Services.
How many KC-10 aircraft were built?
The Air Force received 60 KC-10s, the last delivered on November 29, 1988. The Netherlands also converted two used DC-10-30CFs into KDC-10 tankers.
Why was the KC-10 retired before the KC-135?
The Air Force announced in January 2023 that all KC-10s would retire by September 30, 2024, as squadrons moved to the KC-46. The KC-135 stayed in service, and more than 370 of them remained after the KC-10 left.
What is the difference between the KC-10 and the KC-135?
The KC-10 is a larger, DC-10-based aircraft with a boom and a hose and drogue system. The KC-135 is a smaller Boeing tanker that has stayed in service far longer.
Sources and references used for research and fact-checking.