Saturday, November 12, 2011

The McDonnell Douglas MD-11


!±8± The McDonnell Douglas MD-11

I

The McDonnell-Douglas MD-11, intended successor to its earlier DC-10 and the third widebody tri-jet after the DC-10 itself and the Lockheed L-1011 TriStar, traces its origins to the General Electric and Pratt and Whitney engine competition to provide a suitable powerplant for the Lockheed C-5A Galaxy military transport, resulting in the first high bypass ratio turbofan, while the DC-10, the result of American Airlines' 1966 requirements for a 250-pasenger transcontinental airliner, had been built in five basic versions, inclusive of the DC-10-10, the DC-10-15, the DC-10-30, the DC-10-40, and the KC-10 Extender, achieving an ultimate production run of 446. Program cost overruns had intermittently necessitated the Douglas Aircraft Company's merger with McDonnell, hitherto a military aircraft manufacturer, in order to ensure survival of both the company and its aircraft.

Douglas design studies for both narrow and widebody successors, powered by high bypass ratio turbofans and accommodating 150 passengers, had been initiated as far back as the late-1970s. Although no definitive aircraft program had, in the event, been launched, detailed market analysis, along with new technological research, would later prove valuable to the eventual design. The 60 orders for the KC-10 had enabled Douglas to maintain the basic DC-10 production line longer than it would have if it had only relied on commercial orders, thus delaying the need for a replacement. Yet, because it would be based upon its earlier-generation counterpart, it could proceed through its definition and design phase far more rapidly 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 that aircraft, however--whose five basic versions had shared the same fuselage length and cross-section--the projected successor of 1979 had featured a 40-foot fuselage stretch capable of accommodating 340 mixed-class passengers, three General Electric CF6-50J turbofans producing 54,000 pounds of thrust each, a strengthened wing, and a 630,000-pound gross weight.

The resultant DC-10-60, paralleling the earlier, stretched, long-range DC-8-60 series, had offered a 75-passenger increase over the DC-10s of Air New Zealand and Swissair who had been targeted as potential launch customers, but use of the existing wing had severely eroded performance, and five-foot extensions, coupled with a new wing fillet and active ailerons to reduce gust loads, had considerably improved it. Indeed, revised trailing edge flaps and a larger tailcone had resulted in a 24-percent fuel reduction over that of the DC-10 and its seat-mile costs had been lower than those of the four-engined Boeing 747.

Program launch, intended for 1979, had been usurped by Douglas's further definition of its versions, which, designated "DC-10-61," "DC-10-62," and "DC-10-63," had even more closely reflected the DC-8-61, DC-8-62, and DC-8-63 nomenclatures. The DC-10-61, for instance, had been intended as a domestic variant with the 40-foot fuselage stretch and a 390-passenger capacity, and had been powered by 60,000 thrust-pound engines. The DC-10-62, with a reduced, 26.7-foot fuselage insertion, had been intended for very long-range operations, with a 14-foot wingspan increase, active ailerons, and a four-wheeled centerline main undercarriage unit. It had been intended to carry some 40 fewer passengers than the -61, while the -63 had combined the design features of both, resulting in a high-capacity, long-range variant.

A series of intermittent DC-10 accidents, none of which had been traced to an inherent design flaw, along with the prevailing economic recession, had precluded further Super DC-10 development at this time, although one of its features, eventually incorporated in its successor, had been flight-tested on a Continental Airlines DC-10-10 in August of 1981. Winglets, extending both above and below the wing tip, and varying in size, had resulted in a three-percent fuel reduction because of an equal decrease in generated drag.

Thus buoyed only by MD-80 sales, the Douglas Aircraft Company rode the recession. A projected DC-10 replacement, bearing an MD-11X-10 designation in 1984 and offering considerably more advancement than the original Super 60 series had, had been most closely based on the DC-10-30 with a 580,000-pound maximum take off weight, a 6,500-nautical mile range with a full payload, and either three General Electric CF6-80C2 or Pratt and Whitney PW4000 engines. A higher-capacity version, to be offered in parallel with the basic airframe, had featured a 22.3-foot fuselage stretch, to permit 331 mixed-class passengers to be carried over 6,000-mile ranges and had a corresponding 590,000-pound gross weight. American, Delta, Lufthansa, and Toa Domestic Airlines, considering this iteration, had suggested refinements which had later been incorporated in the definitive aircraft.

By the following year, the board authorized order solicitations, although both versions had, by this time, featured the same fuselage length, the medium-range variant, at a 500,000-pound gross weight, offering a 4,781-mile range, and the long-range counterpart, at a 590,000-pound gross weight, offering a 6,900-mile range. Accommodating some 335 passengers in a typically mixed arrangement, they introduced composite construction, a two-person cockpit, and an advanced electronic flight system.

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

The MD-11, which had rolled out for the first time some three years later in September of 1989 in Long Beach, California, and had been registered N111MD, had been devoid of its engines, winglets, vertical stabilizer, and paint scheme, but displayed the logos of the 29 customers which had ordered or optioned the type by this time. As these surfaces had subsequently been added, however, it bore a close similarity to the DC-10-30 from which it had been derived.

Featuring an 18.6-foot stretch over that aircraft, attained by means of two fuselage plugs, it retained its nose and cockpit sections, but introduced an elongated, drag-reducing, chisel-shaped tailcone, and offered a 201.4-foot overall length when fitted with General Electric engines, or a 200.11-foot overall length with Pratt and Whitney powerplants.

The two-spar Douglas airfoil, built up of chordwise ribs and skins and spanwise stiffeners, featured a 169.6-foot span, a 35-degree sweepback at the quarter chord, and six degrees of dihedral, rendering a 7.9 aspect ratio and a 3,648-square-foot area. Low-speed lift was augmented by new, full-span leading edge slats and redesigned, double-slotted trailing edge flaps, while roll control was provided by inboard, all-speed ailerons made of metal with composite skins, and outboard, low-speed ailerons which drooped with the trailing edge flaps during take off and were entirely constructed of composite material. Each wing also contained five spoiler panels.

Fuel, carried in wing integral tanks, totaled 40,183 US gallons.

Up- and downward-extending winglets, installed on the wingtips themselves, had provided the greatest distinction to the DC-10. Harnessing the drag-producing vortex otherwise created by wingtip pressure differential intermixing, they had been comprised of a seven-foot, upward-angled section made of a conventional rib and spar, but covered with an aluminum alloy skin and completed by a carbonfibre trailing edge, and a 2.5-foot, downward-angled section made entirely of carbonfibre, collectively encompassing a 40-square-foot area.

Because of the increased moment-arm and computer-controlled longitudinal stability augmentation software, the MD-11's horizontal tail had been 30 percent smaller than that of the DC-10 and featured a 2,000 US gallon integral trim tank which increased range and facilitated in-flight center-of-gravity optimization. Its advanced, cambered airfoil, and reduced, 33-degree sweepback, coupled with an electromechanically-activated variable incidence tailplane fitted with two-section, slotted, composite trailing edge elevators on either side, resulted in a 1,900-pound structural weight reduction and decreased in-flight drag.

Power had been provided by three 62,000 thrust-pound General Electric CF6-80C2 or 60,000 thrust-pound Pratt and Whitney PW4462 high bypass ratio turbofans, two of which had been pylon-attached to the wing leading edge underside and one of which had been installed in the vertical tail aft of the fin torsion box. Tracing its origins to the 41,000 thrust-pound TF39 engine originally developed for the Lockheed C-5A galaxy, the former had evolved into the quieter, more advanced CF-6 intended for commercial operation, and its 40,000 thrust-pound CF6-6D had powered the domestic DC-10-10, while its 48,000 thrust-pound CF6-50C had powered the intercontinental DC-10-30, along with the Airbus A-300 and some versions of the Boeing 747. The even more advanced CF6-80A had also been chosen to power the A-310 and the 767.

Incorporating the CF-6's core, with a larger, 93-inch, two-shaft fan, the CF6-80C2 powering the MD-11 had offered 17-percent more thrust and had a bypass ratio of 5.05. Linked to a full authority digital engine control system, which itself had provided electronic autothrottle and flight management system interface, the turbofan had offered reduced fuel burn.

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

The hydraulically-actuated, tricycle undercarriage, like that of the DC-10-30, had been comprised of a twin-wheeled, forward-retracting nose unit; two quad-wheeled, laterally retracting main gear bogies; and a twin-wheeled, forward-retracting, fuselage centerline strut, all of which had featured oleo-pneumatic shock absorbers.

The MD-11 cockpit, significantly deviating from the DC-10's, had been operated by a two-person crew, the third, or flight engineer, position replaced by digital avionics and computerized flight control and management systems, while the Aircraft System Control, or ASU, had been comprised of five independent, dual-channel computers which automated all of his previous functions.

The passenger cabin, designed for flexibility, had incorporated seat, galley, lavatory, and garment closet installation on cabin length-running tracks whose one-inch increments facilitated multiple configurations and densities and rapid rearrangements, thus permitting carriers to operate the type on scheduled flights during the week and on high-density/charter services during weekends. Compared to the DC-10 cabin, the MD-11 featured light-weight side panels and seat assemblies; improved lighting; larger, restyled overhead storage compartments which tripled the per-passenger volume to three cubic feet; standard centerline bins aft of the second door; and provision for overhead crew rest beds.

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

The MD-11, with a 114,100-pound weight-limited payload, had a 602,500-pound maximum take off weight. Accommodating 298 three-class passengers, it had offered a 6,840-nautical mile range, including FAA-required reserves.

First taking to the skies on January 10, 1990 from Long Beach, the MD-11 had performed stability and control tests over Edwards Air Force Base, achieving a maximum altitude of 25,000 feet and a 300-knot speed before concluding a highly successful two-hour, 56-minute maiden flight. Three hundred fifteen orders and options had been received for the type by this time.

The certification program, which had entailed four General Electric CF6-80C2 and one Pratt and Whitney PW4460 powered airframe, had notched up several commercial tri-jet records, including a 9,080-mile flight from Anchorage, Alaska, on July 31, 1990, with the fourth prototype, which had remained aloft for 16 hours, 35 minutes.

Type certification had been achieved on November 8 for the CF6-80C2-powered version and December 19 for the PW4460 aircraft, while clearance had been given for Category IIIB landings the following April.

II

Finnair, the type's launch customer, had taken delivery of 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 of 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 Junkers F.13 aircraft, before expanding to Stockholm, with an intermediate stop in Turku, in cooperation with Sweden's ABA. Finnish domestic route development, because of the country's profusion of lakes, had necessitated floatplane equipment, although post-1936 airport construction had enabled it to acquire two de Havilland Rapide Dragon biplanes and, later, two Junkers Ju.52/3ms.

Shortly after World War II-mandated flight suspension had been lifted, the fledgling airline, now 70-percent government owned and renamed "Aero O/Y Finish Air Lines," had reestablished its Helsinki-Stockholm sector and acquired nine DC-3s.

The 1950s, characterized by continental route system expansion and modern, Convair 340 aircraft acquisitions, had taken it to Dusseldorf, Hamburg, London, and Moscow from a steadily expanding Helsinki flight hub, and the type had been superseded by the slightly higher-capacity Convair 440.

The MD-11, powered by General Electric CF6-80C2D1F engines and configured for 58 business class and 278 economy class passengers, had been ordered to replace its DC-10-30s, and had first been deployed on the Helsinki-Tenerife route on December 29, 1990, to amass initial operating experience before being transferred to the North American and Far Eastern sectors for which it had been intended.

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

The first, to Japan, had spanned 4,862 miles and had entailed a nine-hour, 35-minute block time, and had been operated by the first MD-11 to enter passenger-carrying service, OH-LGA.

The tall, dense trees surrounding Helsinki's Vantaa International Airport, still wearing their yellow and gold autumn coats, appeared diffused as the biting, 30-degree wind whirled snow flurries toward the geometric pattern of ramps, taxiways, and runways. The goliath, blue-trimmed Finnair MD-11 tri-jet, currently the only widebody on the white-dusted tarmac accompanied by a myriad of narrow body DC-9, MD-80, and 737-300 twinjets, was towed to Gate A-4 30 minutes before its scheduled, 1620 departure time amid the late-afternoon, diminished Nordic light.

The MD-11's two-person cockpit, a radical departure from the DC-10's, sported six eight-square-inch Cathode Ray Tube (CRT) glass display units, comprised of the duplicated Primary Flight Display (PFD), Navigation Display (ND), Engine and Alert Display (EAD), and Systems Display (SD) schematics, while the Automatic System Controllers, located on the overhead panel, were subdivided 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), featured controls for autopilot and flight director mode selections, as well as flight management system mode change controls, inclusive of speed (SPD), navigation (NAV), and profile (PROF).

The pending, trans-Siberian flight's departure and destination points, weights, moments, flight plan, take off runway (04), and take off performance calculations, obtained from the station-prepared load sheet, had been entered into the keypad-resembling Multifunction Control Display Unit (MCDU) located on the center pedestal between the two pilots. The flight's Standard Instrument Departure (SID) had subsequently been loaded into the flight management system during inertial reference system initialization.

The number three engine, the first to be started and the furthest from the bleed air source, had been engaged by pulling the Engine Start Switch, its start valve moving into the open position, as verified by an amber confirmation light. When the N2 compressor speed had equaled 15 percent, the start lever had been moved to the "On" position and the engine start switch, reflecting an exhaust gas temperature (EGT) of between 45- and 52-percent, had popped in, the start valve now closed and the amber light disilluminating. The engine's N1 tachometer had settled at 23-percent and its exhaust gas temperature had hovered at the 700 degree Fahrenheit mark. The sequence had then been repeated for the other two turbofans, followed by completion of the "After Start Checklist."

Tug-maneuvered from its nosed-in parking position, the MD-11, operating as Flight AY 914, had initiated its autonomous movement with an almost imperceptible throttle advancement, testing its flight surfaces and following Vantaa Ground Control taxi instructions.

Navigating the snow-patched, blue light-lined taxiways in virtual darkness, the lumbering tri-jet made a 180-degree turn on to Runway 04 with the aid of its nose wheel steering tiller, the nose wheel itself positioned so far behind the cockpit that the aircraft had been inched well beyond the strip's centerline before it had actually initiated the turn toward it, its elongated, wide fuselage following it in trailing mode. Full rudder deflection provided ten degrees of steering on the ground, while the nose wheel achieved up to 70 percent of left and right laterability.

Receiving take off clearance, the MD-11, sporting 25 degrees of trailing edge flap, had thundered into initial acceleration as its throttles, manually advanced to the 70-percent position, nourished its huge-diameter General Electric turbofans with a steady stream of fuel, as they swallowed massive quantities of cold air with each, increasingly faster fan rotation. The AUTOPILOT button, located on the Flight Control Panel and engaging the autothrottles themselves, computer-controlled the aircraft into its proper take off thrust setting, coupled with automatic engine synchronization.

Elevator-leveraged into a nosewheel-disengaging rotation, the tri-jet surrendered to the purple, snowflake-blurring dusk, its heavy fuel load exerting a wingtip-curving bending load and its wing leading edge light beams slicing through the obscurity as it climbed out over Runway 15 and the ground light splotches representing Helsinki. Retracting its tricycle undercarriage, the aircraft, whose pitch bars had indicated its correct climb attitude, had automatically adhered to its standard instrument departure course.

Arcing into a shallow right bank over the coast, Flight 914 retracted its trailing edge flaps, although its leading edge slats had remained extended until additional speed had been amassed. Engaging the navigation mode enabled the aircraft to fly its departure profile, while activating the autoflight system, coupled with the "NAV" and "PROF" buttons, ensured that it followed its route, climb, outbound radial, and either air traffic control-assigned or level-off altitude. Airspeed had been maintained at 250 knots below 10,000 feet, at which time it had been permitted to accelerate to 355 or beyond, and its leading edge lights had been retracted.

Surmounting one of many cloud decks, the aircraft crossed the Gulf of Finland, whose dark purple surface had been separated from the horizon by a diffused band of chartreuse light. Increasingly encased in howling slipstream, it passed over the coast of the former Soviet Union at a 472-knot ground speed, flying southwest of St. Petersburg in black skies which had been traced by a thin, glowing orange line on its western horizon, now located behind its left wingtip, as it settled into its initial, 33,000-foot plateau at a 509-knot ground speed, destined for the Ural Mountains and Siberia.

The passenger cabin, sporting diagonal-patterned, light and dark blue upholstery, had featured six rows of seven-abreast, two-three-two, configured business class seats in the forward section, followed by another three aft of the second cross aisle. Economy class seating, entirely in a ten-abreast, three-four-three, arrangement, had included nine rows behind the business class, and 21 in the aft cabin, running between the third and fourth cross aisles.

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

Maintaining a 567-knot ground speed, the MD-11 penetrated the minus 62-egree tropopause at a three-degree nose-high attitude, passing southeast of Arkhangelsk over the frozen Siberian tundra, with seven hours, 30 minutes remaining on its flight plan. Thinning cloud layer, appearing like sheathing veils, revealed periodic orange and white, population center-represented pearls steadily moving beneath the protruding, massive-diameter turbofans as they propelled it toward Adak and thence south of Naryan-Mar.

Oblivious o the passengers, the upper and lower winglets delayed the otherwise vortex-created wingtip pressure differential intermixing, reducing drag, while the horizontal stabilizer-located trim tank had enabled the aircraft to shift its center-of-gravity rearward, toward its 34-percent aft design limit, further reducing drag and coincident fuel burn by 2.7 percent. The type had standardly operated within a 29- to 32-percent range.

Flight 914's flight plan progress, indicated by a series of position and ground speed readings, had been the result of the IRU's position and velocity coordination with VHF omni-directional radio range (VOR) and distance measuring equipment (DME) stations between Finland and Japan. The Flight Plan (F-PLN) display selected on the MCDU yielded the aircraft's position and waypoints aligned in a vertical manner on the screen, with the estimated times beside them, along with speed and altitude, listed as "Position," "Estimated Time Overhead" (ETO), "Speed" (SPD), and "Flight Level" (ALT).

Passing over Irkutsk, the Yabblonovyy Mountain Range, and Tsitisihar, the aircraft moved ever eastward, toward Vladivostock.

Slicing the darkness and opening day in the Orient, dawn's razor pierced the eastern horizon with a thin cut through which an orange glow had poured ahead of the port wing, somehow emphasizing the cylindrical nature of the planet over which the tri-jet presently arced. "Tomorrow," seemingly eager to unleash its force, streamed through the gradually-enlarging fissure marking the demarcation line between the 24-hour cycle's two modes, its light intensifying and transforming the black, nocturnal doom of Siberia into a cold, partially habitable purple and ultimate dark, pre-dawn blue. The amount of humanity awakening to such light below in the vast wasteland had undoubtedly been infinitesimal. The sun, appearing a red, liquid mercury immersed in a gray-black sea, slowly triumphed over night, its upper, head-like rim becoming distinguishable as it shyly revealed the rest of its body, illuminating the ice-capped, corrugated crust of the Russian mountains covering the area immediately below the fuselage. Initially seeming to float in a dark-brown sea, they became independently distinguishable as the sun stretched its floodlighting rays, like pointing limbs, toward them.

Passing over snaking, copper-reflecting rivers, Flight 914 consumed the two hours, 11 minutes remaining on its flight plan.

Aromas of brewing coffee enticed the groggy, mostly-sleeping passengers from nocturnal slumber in the cabin, a process only partially augmented by breakfast-precedent hot, perfumed towels. The meal itself had included orange juice, a three-egg omelet filled with creamed spinach, thick slices of Danish ham, assorted rolls, Swiss black cherry preserves, Finnish cheese spread fondue, cream wafers, and coffee or tea.

Banking on to a southeasterly heading with the aid of its inboard ailerons, the MD-11 had, after virtually the duration of its cruise, departed Soviet air space for the first time over snow-dusted, chocolate-brown ridges whose peaks had been gently grazed by funnels of vapory mist, following them to the coast and the morning sun-reflected, copper surface of the Sea of Japan. One hour, 23 minutes had remained to Tokyo.

Motionlessly suspended above the water's glass-like surface, it cruised past the silver peak of Mount Fuji, now maintaining an almost due south, 180-degree heading. Banking left over cumulous patches, it forged its final link to Japan, with its time-to-destination having unwound to the 40-minute mark.

The ridges defining Honshu Island appeared ahead.

Tokyo had been reporting clear skies and 20-degree Celsius temperatures.

Traversing the coast over Niigata, the MD-11 had reached a position directly northwest of its destination, with 25 minutes remaining on its flight plan, disengaging itself from its aerial plateau for the first time in almost nine hours by means of the cockpit-selected "NAV" and "PROF" modes.

Induced into a nose-down, slipstream-increasing descent profile, Flight 914 traced the coastline before briefly passing out over the whitecapped Pacific, now ATC-vectored into a series of three right banks. Automatically guided, the aircraft reduced speed to 250 knots as it had transited the 10,000-foot speed restriction, adhering to its Standard Terminal Arrival Route (STAR), propelled by its three massive turbofans whose N1 tachometers had registered almost-stationary, 34-percent readings.

An air traffic control-requested speed reduction, to 200 knots, had, according to the speed tape, required an initial trailing edge flap extension, to 15 degrees.

As the aircraft had sank over brown, tan, and green geometric-patterned farmland on its final approach heading of 340 degrees, the captain had selected the Approach/Land tile, the autoland system armed for an instrument landing system (ILS) approach and poised to capture the glideslope and localizer. The Approach page of the MCDU, yielding landing weight, runway, barometric pressure, and final flap setting speed readings, listed the following for RJAA, the ICAO four-letter code for Tokyo-Narita: a 208-knot "clean" speed, a 158-knot flap extension speed to the 28-degree position, a 161-knot approach speed with 35 degrees of flap, a 158-knot V-reference speed, and a 150-knot touchdown speed.

Sporting significantly increased wing area with leading edge slat and 35 degrees of trailing edge flap extensions, the blue-trimmed Finnair MD-11, projecting its tricycle undercarriage like four outstretched claws, conducted its final approach over the Narita suburbs in the flawlessly-blue morning, passing over the runway threshold. Sinking toward the concrete, during which time altitude calls had been computer-generated, the widebody tri-jet had been pitched into a seven-degree, nose-high flare, retarding its authothrottle to idle at 50 feet and permitting ground effect to cushion its main gear contact. Manually throttled into its reverse thrust mode, it had unleashed its upper wing surface spoilers, their handle having been moved from the retract (RET) setting through the "1/3," "2/3," and "FULL" marks as the aircraft decelerated. The nosewheel thudded on to the ground.

Taxiing to Satellite Four of Narita International Airport's South Wing, the aircraft moved into its Gate 44 parking position at 0855, local time, ending its intercontinental flight sector and completing the circular pattern of nosed-in widebody airliners comprised 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

Initial MD-11 service had not always been so routine. Indeed, the aircraft had demonstrated gross weight and drag increases far in excess of performance projections, resulting in payload and range deficiencies, and Robert Crandall, then American Airlines' CEO, had refused to take delivery of the type, substituting an existing DC-10-30 on the San Jose-Tokyo route for which it had been intended. A series of performance improvement packages (PIP), targeting the shortcomings, had ultimately remedied the situation.

By January 1, 1996, 147 MD-11s had been delivered to 24 original customers and operators who had collectively engaged the aircraft in an 11.6-hour daily utilization, experiencing a 98.3-percent dispatch reliability.

Aside from the initial passenger MD-11, several other versions, although in very limited quantities, had been produced.

The MD-11 Combi, for example, had featured an aft, left, upward-opening freight door, permitting various percentages of passengers, from 168 to 240, and cargo, ranging from four to ten pallets, to be carried on the main deck, 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 .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.


The McDonnell Douglas MD-11

Philips Frx Discount Great Deals Whole House Water Filtration Reviews Swimming Pool Chlorine Levels Guide




No comments:

Post a Comment


Twitter Facebook Flickr RSS



Français Deutsch Italiano Português
Español 日本語 한국의 中国简体。







Sponsor Links