McDonnell Douglas MD-11

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I.

McDonnell-Douglas MD-11, calculated successor to its former DC-10 and third widebody tri-jet after the DC-10 itself and Lockheed L-1011 TriStar, traces its origins to the General Electric and Pratt and Whitney engine competition to provide an appropriate power plant for Lockheed C-5A Galaxy military transport, resulting in the first high bypass ratio turbofan, while DC-10, the result of American Airlines & # 39; 1966 requirements for a 250-passenger transcontinental aircraft, had been built in five basic versions, including DC-10-10, DC-10-15, DC-10-30, DC-10-40 and KC-10 Extender, which achieved an ultimate production run of 446. Program cost overruns periodically necessitated Douglas Aircraft Company's merger with McDonnell, heretofore a military aircraft manufacturer, to ensure the survival of both the company and its aircraft.

Douglas design studies for both narrow and widebody successors, powered by turbofan with a large bypass ratio and with room for 150 passengers, were initiated as far back as the late 1970s. Although no definitive flight program had been launched, if any, detailed market analysis, along with new technological research, would later prove valuable for the possible design. The 60 orders for the KC-10 had allowed Douglas to maintain the basic DC-10 production line longer than it would have done if it had relied solely on commercial orders, thus delaying the need for a replacement. Still, because it would be based on its earlier generation counterpart, it could continue through its definition and design phase far faster than the later, competing Airbus A-340 and Boeing 777, entering the market earlier than these aircraft and tapping into an existing DC -10 customer base for potential sales.

Unlike the aircraft, however – whose five basic versions had the same body length and cross section – the expected successor of 1979 contained a 40-foot body stretch capable of accommodating 340 mixed passengers, three General Electric CF6-50J turbofan producing 54,000 pounds of pressure each, a strengthened wing and a gross weight of 630,000 pounds.

The resulting DC-10-60, parallel to the previous stretched, long-range DC-8-60 series, had offered a 75-passenger increase over the DC-10 & # 39; s of Air New Zealand and Swissair which were has been targeted as potential launch customers, but using the existing wing had greatly eroded performance, and five-foot extensions, combined with a new wing fillet and active air remover to reduce wind breath loads, had significantly improved it. In fact, revised tailgate and a larger tail knob had resulted in a 24 percent fuel reduction over the DC-10, and the seat mile cost had been lower than the cost of the four-engine Boeing 747.

Program launch, estimated for 1979, had been overridden by Douglas's further definition of its versions, which are designated "DC-10-61," "DC-10-62," and "DC-10-63," had yet more reflected DC-8-61, DC-8-62 and DC-8-63 nomenclature. For example, the DC-10-61 had been designed for a domestic variant with 40-foot body stretch and a capacity of 390 passengers and had been powered by 60,000 powertrain engines. The DC-10-62, with a reduced, 26.7-foot fuselage insert, was intended for very long-range operations, with a 14-foot wingspan increase, active air traps, and a four-wheel mid-line main chassis. It was intended to carry approx. 40 fewer passengers than -61, while -63 had combined the design features for both, resulting in a long-range, high-capacity variant.

A number of intermittent DC-10 accidents, none of which had been traced to an inherent design flaw, along with the prevailing economic recession, had ruled out further Super DC-10 development at this time, though one of its features that eventually was incorporated into its successor, had been flight tested on a Continental Airlines DC-10-10 in August 1981. Winglets extending both above and below the wing tip and varying in size had resulted in a three percent fuel reduction due to a straight fall in generated feature.

Thus, the Douglas Aircraft Company only rode down from MD-80 sales and receded. A projected DC-10 replacement, which had a MD-11X-10 designation in 1984 and offers significantly more progress than the original Super 60 series had, was closest based on DC-10-30 with a maximum start of 580,000 pounds weight, a 6,500-nautical mile full-load range and either three General Electric CF6-80C2 or Pratt and Whitney PW4000 engines. A higher-capacity version to be offered in parallel to the basic aircraft frame had a 22.3-foot body stretch, allowing 331 mixed-class passengers to be carried over 6,000-mile intervals and had a corresponding gross weight of 590,000 pounds. American, Delta, Lufthansa and Toa Domestic Airlines, considering this iteration, had proposed improvements that would later be incorporated into the final flight.

In the following year, the board approved order takings, although both versions at this time had the same body length, the medium variant, with a gross weight of 500,000 pounds, offering a range of 4,781 miles and the long-range counterpart to a gross weight of 590,000 pounds and offers a range of 6,900 miles. With room for approx. 335 passengers in a typical mixed arrangement introduced the composite construction, a two-seater cockpit and an advanced electronic flight system.

At the time of the official program launch, which took place on December 30, 1986, 92 orders and options had been ordered by Alitalia, British Caledonian, Federal Express, Korean Air, SAS, Swissair, Thai Airways International and Varig.

The MD-11, which rolled out for the first time some three years later in September 1989 in Long Beach, California, and had been registered N111MD, had exposed its engines, wings, vertical stabilizer and paint, but displayed the logos of the 29 customers who had ordered or selected the type at this time. However, as these surfaces were subsequently added, it bore a close resemblance to DC-10-30 from which it was derived.

With an 18.6-foot stretch over this aircraft, achieved using two straps, it maintained its nose and cockpit sections, but introduced an elongated, drag-reducing, chisel-shaped tailbone and offered a total length of 201.4 feet when it was fitted with General Electric engines or a total length of 200.11 feet with Pratt and Whitney power plants.

The two-spar Douglas airfoil, built of chordal ribs and skins and span, contained a 169.6-foot span, a 35-degree sweepback at a quarter-chord and six-degree dihedral, making a 7.9 aspect ratio and a 3,648 – square meter area. Low-speed lifts were enhanced by new full-span forward and redesigned, double-slotted tailgates, while roller control was provided by inboard, all-speed ailerons made of metal with composite skins and low-speed outboard ailerons that dropped with tailgates during takeoff and was entirely constructed of composite material. Each wing also contained five spoiler panels.

Fuel transported in the wing's integrated tanks totaled 40,183 US gallons.

Up and down blades, installed on the blade tips themselves, had made the biggest difference to the DC-10. Utilizing the tensile-producing vortex otherwise created using a blend of the wing tip difference, they had been composed of a seven-foot up-angled section made of a conventional rib and spar, but covered with an aluminum alloy skin and finished with a carbon fiber rear edge and a 2.5-foot downward angular portion made entirely of carbon fiber, which together comprises a 40 square foot area.

Due to the increased torque arm and computer-controlled longitudinal stability enhancement, the MD-11 & # 39; s horizontal tail had become 30 percent smaller than the DC-10 and contained a 2,000 US gallon integrated trim tank which increased range and facilitated optimization under the center of gravity. Its advanced, chambered airplane and reduced, 33-degree sweepback, coupled with an electromechanically activated variable incidence tailplane equipped with two-section, slotted, composite rear edge with lifting edges on each side resulted in a structural weight reduction of 1,900 pounds and dropped in flight

Power was provided from three 62,000 thrust-pounds General Electric CF6-80C2 or 60,000 thrust-pounds Pratt and Whitney PW4462 large bypass ratios, two of which were pylon attached to the front of the wing on the underside and one of which had been installed in it vertical tail at the back of the fin torsion box. Tracing its origins to the 41,000 TF39 engine originally developed for the Lockheed C-5A Galaxy, the former had evolved into the quieter, more sophisticated CF-6 intended for commercial operation, and its 40,000-pound engine. The CF6-6D pound had powered the domestic DC-10-10, while its 48,000-pound CF6-50C had driven the DC-10-30 intercontinental with the Airbus A-300 and some versions of the Boeing 747. The even more advanced CF6 The -80A had also been selected to operate the A-310 and 767.

Incorporation of CF-6 & # 39; s core with a larger, 93-inch, two-shaft fan, the CF6-80C2, which operates the MD-11, had offered 17 percent more pressure and had a bypass ratio of 5.05. Associated with a full-authority digital engine control system, which itself had provided electronic car throttle and aircraft control system interface, the turbofan had offered reduced fuel combustion.

Alternatively, Pratt and Whitney PW4060, whose reduced length equally reduced the overall length of the aircraft by five inches, had been the only other customer option. Rolls Royce RB.211-524L Trent, briefly listed as a third alternative, had been specified by Air Europe for its 18 fixed and option orders, but its parent company's financial collapse precluded the continuing offer.

The hydraulically actuated, three-wheeled undercarriage, like the DC-10-30, had been composed of a dual-wheel, forward-pulling nose unit; two four-wheel, laterally retractable main gear bogies; and a two-wheeled, forward-facing, middle strut in the fuselage, all equipped with oleo-pneumatic shock absorbers.

The MD-11 cockpit, significantly different from the DC-10 & # 39; s, had been served by a two-person crew, the third or flight technician, position replaced by digital airplane and computerized flight control and control systems, while Aircraft System Control, or ASU, had been composed of five independent two-channel computers, that automated all his past functions.

The passenger cabin, designed for flexibility, had built-in seat, galley, toilet and wardrobe installation on cable-length tracks, whose 1-inch steps facilitated multiple configurations and densities and rapid rearrangements, allowing airlines to operate the type on scheduled flights during the week and on high-density / charter services this weekend. Compared to the DC-10 cabin, the MD-11 contained light side panels and seating units; improved lighting; larger, recessed overhead storage compartments that triple the volume per passenger to three cubic feet; standard centerline garbage can aft of the other door; and opportunity for resting places above the main herd.

A typical two-class, 323-passenger configuration had resulted in 34 six-seat first-class seats on a 41- to 42-inch pitch and 289 nine-abreast economy class seats on a 33- to 34-inch pitch, while a three-class arrangement included 16 six-seat first-class seats on a 60-inch pitch, 56 seven-seat business-class seats on a 38-inch pitch, and 221 nine-abreast economy class seats on a 32-inch pitch The maximum capacity, in a ten-aperture, three- four-three configuration, had been 409.

The MD-11, with a weighted payload of 114,100 pounds, had a maximum takeoff weight of 602,500 pounds. With seating for 298 passengers in three classes, it had offered a range of 6,840 nautical miles, including FAA-required reserves.

MD-11, which first took to the skies on January 10, 1990 from Long Beach, had conducted stability and control tests over Edwards Air Force Base and achieved a maximum altitude of 25,000 feet and a speed of 300 knots before completing a very successful two – hour, 56 minute maiden flight. Three hundred fifteen orders and options had been received for the type at this time.

The certification program, which carried four General Electric CF6-80C2 and one Pratt- and Whitney PW4460-powered aircraft frame, had on July 31, 1990, wrapped up several commercial tri-jet entries, including a 980-km flight from Anchorage, Alaska, with the fourth prototype that had remained high for 16 hours, 35 minutes.

Type certification was obtained on November 8 for the CF6-80C2-powered version and December 19 for the PW4460 aircraft, while category IIIB landings were granted the following April.

II

Finnair, type & # 39; s launch customer, had delivered its first aircraft, registered OH-LGA, at a ceremony in Long Beach on November 29, 1990, and a representative intercontinental sector with this aircraft had been made two years later, in October 1992.

Founded on November 1, 1923 by Bruno L. Lucander, the private carrier, then designated "Aero O / Y," had inaugurated service the following March to Reval, Estonia, with Junker's F.13 aircraft before expanding to Stockholm, with a stopover in Turku, in collaboration with Sweden's ABA. Finnish domestic route development due to the country's abundance of lakes had required airplane equipment, although the post-1936 airport construction had allowed it to acquire two de Havilland Rapide Dragon biplanes and later two Junkers Ju.52 / 3ms.

Shortly after the mandated World War II flight suspension was abolished, the new airline, now 70 percent owned and renamed "Aero O / Y Finish Air Lines," restored its Helsinki-Stockholm sector and acquired nine DCs -3 & # 39; is.

The 1950s, characterized by continental route system expansion and modern, Convair 340 flight purchases, had taken it to Dusseldorf, Hamburg, London and Moscow from an ever-expanding Helsinki aircraft hub, and the type was replaced by the slightly higher capacity Convair 440.

MD-11, powered by General Electric CF6-80C2D1F engines and configured for 58 business class and 278 economy class passengers, was ordered to replace its DC-10-30 & # 39; s and was first deployed on the Helsinki-Tenerife route on December 29 , 1990, to gather the first operating experience before transferring to the North American and Far Eastern sectors for which it was intended.

Its two MD-11s served the Helsinki-Tokyo and Helsinki-Bangkok-Singapore routes, while the DC-10-30s continued to operate the New York and Beijing sectors.

The first, to Japan, had spanned 4,862 miles and had a nine-hour, 35-minute blocking time, and had been served by the first MD-11 to enter passenger transport, OH-LGA.

The tall, dense trees that surround Helsinki & # 39; s Vantaa International Airport, still wearing their yellow and gold autumn coats, seemed diffuse as the biting, 30-degree wind swirled snow flurries against the geometric pattern of ramps, taxis and runways. The goliath, blue-trimmed Finnair MD-11 tri-jet, currently the only widebody on the white dusty tarmac accompanied by a myriad of narrow-body DC-9, MD-80 and 737-300 twin beams, was towed to Gate A -4 30 minutes before the planned, 1620 departure time in the middle of the afternoon, Nordic light diminished.

MD-11 & # 39; s two-person cockpit, a radical departure from DC-10 & # 39; s, sported six eight-square-inch Cathode Ray Tube (CRT) glass display units consisting of the duplicate primary Flight Display (PFD), navigation display (ND), engine and alarm display (EAD), and system display (SD) schedules, while the automatic system controllers located on the main panel were divided into sections for hydraulics, electrical, pneumatics and fuel, each controlled by two independent computers. The Flight Control Panel (FCP) itself, located on the Glareshield Control Panel (GCP), contained controls for selecting the autopilot and flight director mode, as well as flight control system mode control controls, including speed (SPD), navigation (NAV), and profile (PROF).

The pending, trans-Siberian fly & # 39; s departure and destination points, weights, moments, flight plan, runway take-off (04) and start of calculations obtained from the station-prepared load sheet had been entered in keyboards similar to the MCDU located on the middle pedestal between the two pilots. The flight's standard instrument departure (SID) had subsequently been loaded into the flight control system during inertial reference system initialization.

The engine number three, the first to start and furthest from the vent source, had been activated by pulling the engine start switch where its starter valve moves in the open position, as confirmed by an amber confirmation light. With the N2 compressor speed equal to 15 percent, the starter handle was moved to the "On" position and the engine start switch reflecting an exhaust temperature (EGT) of between 45 and 52 percent had entered, the starting valve is now closed, and amber light lights down. The engine's N1 tachometer was down 23 percent and its exhaust temperature was hovering at the 700-degree Fahrenheit mark. The sequence was then repeated for the other two turbofans, followed by the completion of the "After Start Checklist".

Pulled from its nose-in-parking position, the MD-11, which operated as Flight AY 914, had initiated its autonomous movement with an almost imperceptible throttle, tested its flight surfaces and followed Vantaa Ground Control taxi instructions.

Navigating the snow-covered, blue light-lined taxis in virtual darkness, the incoming tri-jet made a 180-degree trip to runway 04 using its nose wheel, the steering wheel, the nose wheel itself located so far behind the cockpit that the aircraft had been emptied far out above the centerline of the strip before it had actually begun the turn toward it, its elongated, wide flight hooks that followed it in the trunk. Full rudder deflection provided ten-degree steering on the ground, while the nose wheel achieved up to 70 percent of left and right sidelines.

The MD-11, which received 25 degrees tailgate, received start-free distance, had thundered into the first acceleration as its throttle, manually leading to the 70-percent position, approached its huge diameter General Electric turbofan with a steady stream of fuel, as they swallowed enormous amounts of cold air with each, ever faster fan rotation. The AUTOPILOT button, located on the Flight Control Panel and switching on the autotrottles themselves, computer-controlled the aircraft in its proper take-off mode, combined with automatic engine synchronization.

The elevator gear in a nose wheel-releasing rotation, the tri-jet surrendered to the purple, snowflake-blurring dusk, its heavy fuel load exerting a wing-tip curvature bending load, and its wing front light rays slicing through the haze as it climbed out over the runway 15 and the spotlights represent Helsinki. By withdrawing its tricycle, the aircraft, whose pitch bars had indicated its correct pitch, automatically adhered to its standard instrument flight.

Driving into a low right bank across the coast, Flight 914 retracted its tailgate, though its front slats remained extended until an extra speed was collected. Enabling the navigation feature enabled the aircraft to fly its departure profile, while activating the autoflight system, combined with the "NAV" and "PROF" buttons, ensured that it followed its route, climb, outbound radial and either assigned air traffic control or level-off height. Airspeed had been maintained at 250 knots below 10,000 feet, at which time it had been allowed to accelerate to 355 or above, and its leading-edge lights had been withdrawn.

Flying over one of many cloud decks, the plane crossed the Gulf of Finland, whose dark purple surface had been separated from the horizon by a diffuse band of chartreuse light. Increasingly encased in howling slip currents, it passed over the coast of the former Soviet Union at a speed of 472 knots, flying southwest of St. Petersburg. Louis Petersburg in black sky, traced by a thin, glowing orange line on its western horizon, now positioned behind the left wing tip as it settled into the original 33,000-foot plateau at a speed of 509 knots, destined for the Ural Mountains and Siberia.

The passenger cabin, sporting diagonal pattern, light and dark blue upholstery, had contained six rows of seven-aabreast, two-by-two, configured business class seats in the front section, followed by another three acts on the second crossing. Economy class seating, all in a scheme of ten consecutive, three-by-three, had included nine rows behind the business class and 21 in the rear cabin, running between the third and fourth crossings.

Dinner in the latter, according to its bilingual English and Japanese menu (which, in October 1992, had ironically shown an in-flight profile of one of Finnair & # 39; s DC-10-30s), had included a selection of aperitifs, beer , wine and non-alcoholic beverages served with lightly salted peanuts and smoked almonds; a seafood salad with crab meat and mushroom on a salad bed with jumbo shrimp, slices of cucumbers and cherry tomatoes; a basket of hot whites and wheat rolls with Finnish butter; mango beef or chicken in curry-coconut cream sauce; French camembert cheese with crispy rye biscuits; raspberry mousse cake; coffee or Japanese tea; a selection of liqueurs; coins after dinner; and hot towels.

Maintaining a speed of 567 knots of ground, the MD-11 minus the 62-egree tropopause penetrated at a three-degree nose-high stance and passed southeast of Arkhangelsk over the frozen Siberian tundra, with seven hours, 30 minutes remaining on its flight schedule. Thinner cloud layers, which look like envelope veils, revealed periodic orange and white, represented beads in the center of the population, which moved smoothly under the prominent, massive diameter turbofans as they propelled it toward Adak and thence south of Naryan-Mar.

Unknowing passengers, upper and lower wing flats delayed the otherwise swirling wing tip differential intermixing, which reduced drag, while the horizontal stabilizer-positioned trim tank had allowed the aircraft to shift its center of gravity backward towards its 34 percent rear design limit. and coincident fuel combustion by 2.7 percent. The type had usually operated within a range of 29 to 32 percent.

Refugee 914 & # 39; The flight plan's progress, indicated by a range of ground speed measurement and measurement, was the result of IRU & # 39; s position and speed coordination with VHF omni-directional radio range (VOR) and distance measuring equipment (DME) stations between Finland and Japan. Flight Plan (F-PLN) view selected at the MCDU provided the aircraft position and route points adjusted vertically on the screen with the estimated times adjacent to them, along with the speed and altitude listed as "Position," "Estimated Time Overhead "(ETO)," Speed ​​"(SPD) and" Flight Level "(ALT).

Passing Irkutsk, the Yabblonovyy mountain range and Tsitisihar, the aircraft was still moving east, towards Vladivostock.

Cutting the darkness and opening day in the Orient, dawn's razor pierced the eastern horizon with a thin cut, through which an orange glow was poured in front of the whistle, somehow emphasizing the cylindrical nature of the planet as the triage currently illuminating. "Tomorrow," apparently eager to unleash its power, streamed through the gradually enlarged gap marking the boundary line between the 24-hour cycle & # 39; s two states, its light intensifies and transforms the black, nocturnal downfall of Siberia into a cold, partially habitable purple and ultimate darkness, before dawn blue. The amount of humanity waking up to such light below in the great wilderness had undoubtedly been endless. The sun, which appeared like a red, liquid mercury immersed in a gray-black sea, slowly triumphed at night, discerning its top, head-like edge as it revealed with shade the rest of its body, illuminating the icy coffee, undulating crust of the Russian mountains that cover the area immediately below the hull. Originally seeming to float in a dark brown sea, they became independently separable as the sun stretched its radiant light rays, like limbs, towards them.

As he passed over talking, copper-reflecting rivers, Flight 914 consumed the two hours, 11 minutes remaining on its flight schedule.

Aromas of brewing coffee enticed the groggy, mostly sleeping passengers from nightly sleep in the cabin, a process that was only partially enhanced by hot, perfumed towels for breakfast. The meal itself had orange juice, a three-egg omelet filled with creamy spinach, thick slices of Danish ham, various rolls, Swiss black cherry preserves, Finnish cheese-spread fondue, cream wafers and coffee or tea.

MD-11 knocked on a south-easterly direction using its interior airfields, after practically the duration of its cruise, for the first time, leaving Soviet airspace over snow-dusted, chocolate-brown rumors whose peaks were gently grazed by vapors of mist, which follows them to the coast and in the morning sun-reflected, copper surface in the Sea of ​​Japan. One hour, 23 minutes was left for Tokyo.

Movingly suspended over the glass-like surface of the water, it crossed the silver peak of Mount Fuji, which now maintains a nearly due south, 180 degree direction. Banking back abandoned plastics, it forged its final connection to Japan, with its time-to-destination having wound up to the 40-minute mark.

The ridge, which defines Honshu Island, appeared.

Tokyo had reported clear skies and 20-degree Celsius temperatures.

Across the coast of Niigata, the MD-11 had reached a position directly northwest of its destination, with 25 minutes remaining on its flight plan, and detached from its air plateau for the first time in nearly nine hours using the chosen cockpit "NAV" and "PROF" modes.

Introduced in a nose-down, slip-current-rising descent profile, the Flight 914 tracked the coastline before briefly passing out over the white-carded Pacific, now the ATC vector in a series of three right-bankers. Auto-controlled, the aircraft reduced speed to 250 knots as it had exceeded the 10,000-foot speed limit in compliance with its Standard Terminal Arrival Route (STAR), propelled by its three massive turbo vans whose N1 tachometers had recorded nearly stationary, 34 percent readings.

According to the speed band, a request for speed reduction for air traffic control to 200 knots had required an initial extension of the tailgate to 15 degrees.

As the plane had sunk over brown, tan and green geometric-patterned farmland at its final approach direction of 340 degrees, the captain had chosen the Approach / Land tile, the Autoland system armed with an Instrument Landing System (ILS) approach and prepared to catch glides and locator. The MCDU & # 39; s Approach Page providing landing weight, runway, barometric pressure, and final flap setting of speed readings stated the following for RJAA, the ICAO four-letter code for Tokyo Narita: a 208 knots "clean" speed, a 158-knot flap extension speed degree position, a 161-knot proximity speed with 35-degree slap, a 158-knot V reference speed, and a 150-knot touchdown rate.

Sporting markedly increased wing area with leading edge slats and 35 degrees of tailgate extensions, the blue-trimmed Finnair MD-11, projecting its tricycle undercarriage like four outstretched claws, made its final approach over Narita suburbs in the flawless blue morning passing over the runway threshold . Sinking toward the concrete in which time altitude calls had been generated by the computer, the broad-legged tri-jet was thrown into a seven-degree, nose-high flare that delayed its autotrottle to 50-foot idle and allowed ground power to cushion its main gear. Manually throttle in its inverted push mode, it had detached its upper wing surface spoilers where their handles had been moved from the retraction setting (RET) through the "1/3," "2/3," and "FULL" markings as retarded aircraft. The nose wheel slid to the ground.

By taxi for satellite four at Narita International Airport & # 39; s South Wing moved the aircraft into its Gate 44 parking lot at 0855, local time, ending its intercontinental aviation sector and ending the circular pattern of nose-in widebody airlines consisting of an Austrian Airlines A-310-300, a Japan Air Lines 747-200B, a British Airways 747-400, an ANA 747-200B, a Northwest 747-200B and a Swissair MD-11.

III

The original MD-11 service had not always been so routine. In fact, the aircraft had shown gross weight and drag increases far beyond performance projections, resulting in payload and range deficiencies, and Robert Crandall, then American Airlines & # 39; The CEO had refused to take delivery of the type, replacing an existing DC-10 -30 on the San Jose-Tokyo route it was intended for. En række ydelsesforbedringspakker (PIP), der var rettet mod manglerne, havde i sidste ende afhjulpet situationen.

Den 1. januar 1996 var 147 MD-11'er blevet leveret til 24 originale kunder og operatører, der kollektivt havde engageret flyet i en 11,6 timers daglig udnyttelse og oplevet en pålidelighed på 98,3 procent.

Bortset fra den oprindelige passager MD-11, var der produceret flere andre versioner, skønt i meget begrænsede mængder.

MD-11 Combi havde for eksempel en bageste, venstre, opadgående godsdør, der tillader forskellige procentsatser af passagerer, fra 168 til 240, og last, der spænder fra fire til ti paller, skulle transporteres på hoveddækket , while lower-deck space had remained unchanged. With a 144,900-pound weight-limited payload, the aircraft had a maximum range of between 5,180 and 6,860 nautical miles.

The MD-11CF Convertible Freighter had featured the main deck door relocated to the forward, port side. Martinair Holland, launch customer for the variant in August of 1991, had placed four firm orders and one option for the type.

The MD-11F, with a 202,100-pound payload, had been a pure-freighter without passenger windows or internal facilities ordered by FedEx, while the MD-11ER Extended Range, launched in February of 1994, had featured a 3,000 US gallon fuel capacity increase carried in lower-deck auxiliary tanks, a 6,000-pound higher payload, a 480-mile greater range, and a new maximum take off weight of 630,500 pounds. World Airways, selecting the Pratt and Whitney PW4462 engine, and Garuda Indonesia, specifying its General Electric CF6-80C2 counterpart, had placed the launch orders.

Dwindling sales, the result of the design's initial performance deficiencies, American Airlines' reputation-damaging public criticisms, order cancellations, and competition from the Airbus A-340 and Boeing 777, had forced McDonnell-Douglas to write down $1.8 million for the program in 1996 and by the following year, after McDonnell-Douglas's merger with the Boeing Commercial Airplane Company, it had no longer been feasible to continue its production. The original Douglas Aircraft Company Building 84, located at Long Beach Airport and incubation point for all McDonnell-Douglas DC-10 and MD-11 widebody tri-jets, had hatched its 200th and last MD-11, a freighter, for Lufthansa Cargo, in June of 2000, and the aircraft, towed across the road to the runway, bore the title, "The perfect end to a perfect era."

The complete production run had included 131 MD-11P Passenger versions, five MD-11C Combis, six MD-11CF Convertible Freighters, 53 MD-11F Pure-Freighters, and five MD-11ER Extended Range variants.

The figures, added to the 446 DC-10s built between 1971 and 1988, had resulted in a total of 646 tri-jets having been produced.

Although McDonnell-Douglas had studied several stretched, re-engined, and rewinged MD-11 successors designated "MD-12s," including a double-decked, quad-engined, A-380-resembling configuration, these ambitious proposals had exceeded the value of the manufacturer itself, and when Taiwan Aerospace had withdrawn financial support for the definitive version, which had reverted to a tri-jet design with an advanced wing, the three-engined widebody, tracing its lineage to the original DC-10, had finally ended, leaving the increasing number of passenger-converted airframes into freighters to carry their pedigrees into the early-21st century.

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