<p>The KC-10A Extender tanker/transport, an off-the-shelf version of the DC-10-30CF airliner, was acquired to fill the USAF's need—identified during Operation Nickel Grass, the US airlift to Israel during the October War of 1973—for a dual-role ATCA (Advanced Tanker/Cargo Aircraft). The US emphasis on rapid deployment of forces in the late 1970s coincided with development of this long-range transport able to haul people and equipment while also functioning as a tanker. In the 1990s, the KC-10 fleet will help the USAF field an expeditionary force to deploy rapidly from US bases to Third World trouble spots.
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<p>The KC-10 is a genuine strategic asset with its capability to carry a full payload of 169,409 lb (76,843 kg) over a range of 4,370 miles (7,033 km), and its facility to be refueled in flight. The value of this tanker/transport is demonstrated when a fighter deploys overseas, with the KC-10 carrying support equipment and personnel while also refueling the fighters en route.
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<p>For the tanker role, the lower section of the KC-10A fuselage is fitted with bladder fuel cells increasing maximum usable fuel to 54,455 US gal (206,134 liters). A boom operator's station is located beneath the rear fuselage where, instead of assuming the prone position as on the KC-135, he or she sits in an aft-facing crew seat. A McDonnell Douglas AARB (Advanced Aerial Refueling Boom) is located on the centerline of the fuselage, with a refueling hose reel unit installed adjacently. This arrangement has permitted single-point refueling of USAF aircraft (with the boom) or US Navy/Marine aircraft (with the hose) on the same mission. Following the heavy demand on tanker assets demonstrated during Operation Desert Storm, the USAF in 1991 announced plans to equip its KC-10 fleet with refueling units on each wing to permit refueling of three aircraft at a time. Prior to the war with Iraq, the 60th and final KC-10 had been fitted with a Flight Refuelling Ltd Mk 32B hose drum pod beneath each wingtip to convert it into a three-point tanker, and underwent lengthy evaluations using this configuration.
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<p>Following the successful outcome of this evaluation, plans were drawn up to configure a total of 20 Extenders in similar fashion by Fiscal Year 1996 and the first such aircraft was flown to Tinker AFB, Oklahoma for modification in September 1993. In service, however, it appears that only sufficient pods will be obtained to equip 15 aircraft, with the balance serving as a reserve to cover routine maintenance and overhaul requirements.
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<p>For its equally important transport role, the KC-10 has an 8-ft 6-in × 11-ft 8-in (2.59-m × 3.56-m) upwards-hinged cargo door on the port side of the fuselage, able to handle most fighter unit support equipment. Powered rollers and winches are installed in the cargo compartment, which has reinforced main deck flooring for palletized loads. While it cannot be loaded/unloaded from ground level like C-130, C-141 and C-5 airlifters, the KC-10 can accommodate up to 25 463L pallets or mixed loads, which typically might include 75 people in airline-style seats and up to 17 cargo pallets. Total usable cargo space exceeds 12,000 cu ft (340 m<su>3</su>).
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<p>The KC-10 is powered by three 52,500-lb (233.53-kN) thrust General Electric CF6-50C2 turbofans. One of the engines is mounted at the base of the tail above the aft fuselage, the other two on pylons beneath the wings.
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<p>The USAF announced its choice of the KC-10A in preference to a possible Boeing 747 version on 19 December 1977. First flight of the KC-10A took place on 12 July 1980, and the first air refueling on 30 October 1980, with a C-5 as the receiver aircraft. The first KC-10A was delivered to the USAF on 17 March 1981. During a six-month operational assessment from May 1981, a KC-10A accompanied eight Air National Guard A-7D aircraft from Tulsa, Oklahoma, to RAF Wittering, England. In addition to furnishing 190,000 lb (86,184 kg) of fuel to the A-7Ds while in flight, the KC-10 also carried support personnel and ground equipment, demonstrating its dual-role function on this single sortie.
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<p>Another memorable achievement occurred in September 1982 when seven KC-10As rendezvoused with 20 MAC C-141B StarLifters near Goose Bay, Labrador, and dispensed 65,000 lb (29,484 kg) of fuel to each. The C-141Bs then flew non-stop across the Atlantic to West Germany where they airdropped paratroopers before returning to the US, where another fuel transfer was achieved off the East Coast some 14 hours after the initial contact. KC-10A Extenders were used similarly when 82nd Airborne Division paratroopers embarked from Fort Bragg, North Carolina, made the parachute assault on Panama's Tocumen Airport during Operation Just Cause in December 1989.
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<p>KC-10A Extenders supported the massive airlift to the Persian Gulf during Operation Desert Shield in 1990. During Operation Desert Storm (1991), 46 KC-10As were located in the combat zone and flew about 20 per cent of the 4,967 sorties which refueled aircraft heading into combat.
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<p>The KC-10A has been officially credited with the best safety record of any USAF aircraft. One aircraft (82-0190) was lost in a ramp fire at Barksdale AFB, Louisiana, on 17 September 1987.
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<p>In its first major change as the USAF shifted to its expeditionary concept in the 1990s, KC-10s were assigned to the 4th Wing at Seymour Johnson AFB, North Carolina, to serve directly with, and deploy with, the wing's F-15E Strike Eagles, to position a tactical force at a foreign airfield halfway around the world on very short notice.
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<p>Normal crew of the KC-10A is four—pilot, co-pilot, flight engineer and boom operator. INS (inertial navigation systems) make a navigator unnecessary. The KC-10A is not intended to support strategic bombers during a nuclear war and, unlike the KC-135, does not have thermal blast curtains or shielding against electromagnetic pulse. KC-10A aircraft have been based at Barksdale AFB, Louisiana; March AFB, California; and Seymour Johnson AFB, North Carolina, although redistribution of the fleet is now under way, with examples of the KC-10A henceforth destined to operate from McGuire AFB, New Jersey; Travis AFB, California and Mountain Home AFB, Idaho. The 60th aircraft was delivered on 29 November 1988.
