McDonnell Douglas MD-11

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MD-11
Air Namibia MD-11
Type	Wide-body aircraft
Manufacturer	McDonnell Douglas / Boeing
Maiden flight	1990-01-10
Status	Active
Primary users	FedEx (58) UPS (24) Lufthansa Cargo (19) KLM (10)
Produced	1988-2000
Number built	200
Developed from	McDonnell Douglas DC-10

The McDonnell Douglas MD-11 is a three-engine medium to long-range widebody airliner, with two engines mounted on underwing pylons and a third engine at the base of the vertical stabilizer. It is based on the DC-10, but featuring a stretched fuselage, increased wingspan with winglets, refined aerofoils on the wing and tailplane, new engines and increased use of composite materials. It features an all-digital glass cockpit that decreases the crew to two from the three required on the DC-10.

Contents 1 History 1.1 Origins 1.2 Development 2 Design 3 Variants 4 Operators 4.1 Passenger 4.2 Cargo 4.3 Previous operators 5 Accidents 6 Specifications 7 References 8 External links 9 Related content

[edit] History

[edit] Origins

Although the MD-11 program was launched in 1986, McDonnell Douglas started to search for a DC-10 derivative as early as 1976. Two versions were considered then. A DC-10-10 with a fuselage stretch of 40ft (12.19m) and a DC-10-30 stretched by 30ft (9.14m). That later version would have been capable of transporting up to 340 passengers in a multi-classes configuration, or 277 passengers and their luggage over 5,300nm (9,815km). At the same time, the manufacturer was searching to reduce wings and engines drag on the trijet. Another version of the aircraft was also envisaged, the "DC-10 global", aimed to counter the risks of loss of orders for the DC-10-30 that the Boeing 747SP and its range were creating. The DC-10 global would have incorporated more fuel tanks.^[1]

While continuing its researches for a new aircraft, McDonnell Douglas designated the whole program as the DC-10 Super 60, having previously been known for a short time as DC-10 Super 50. The Super 60 was to be an intercontinental aircraft incorporating many aerodynamic improvements on the wings, and a fuselage lengthened by 320in (8,12m) to allow up to 350 passengers to seat in a mixed class layout, compared to the capacity of 275 in the same configuration of the DC-10.^[1]

Following more refinements, the DC-10 Super 60 project was proposed, as off 1979, in three distinct versions like the DC-8. The DC-10-61, aimed to be a US domestic aircraft, able to carry 390 passengers on an airframe lengthened by 40 ft (12.19m). Like for the DC-8, the series 62 was proposed as an intercontinental aircraft stretched by 26ft 7in (8.10m) and capable to carry up to 350 passengers. And finally, the series 63 would have incorporated the same fuselage as the DC-10-61 as well as all the aerodynamic refinements of the -62. After the three DC-10 accidents in 1979 (American Airlines, Western Airlines and Air New Zealand) which received great media coverage, the trijet program was seriously damaged by doubts regarding its structural integrity. For these reasons and another downturn in the airline industry, all work on the Super 60 was stopped.^[1]

In 1981, a Continental Airlines DC-10-10 was leased to conduct more research and particularly the effects of the then newly designed winglets could have on an aircraft performances. Different types of winglets were tested during that time in conjunction with the NASA. McDonnell Douglas was again planning new DC-10 versions that could incorporate winglets and more efficient engines developed at the time by Pratt & Whitney (PW2037) and Rolls-Royce (RB.211-535F4). The manufacturer finally rationalised all these studies under the MD-EEE designation, that was later modified to MD-100 following some more changes. The MD-100 was proposed in two versions. The Series 10, having an airframe shorter by 6ft 6in (1.98m) compared to the DC-10 and seating up to 270 passengers in a mixed class configuration; and the Series 20, incorporating a fuselage stretch of 20ft 6in (6.24m) over the DC-10 and able to seat up to 333 passengers in the same kind of configuration as the Series 10. Both versions could be powered by the same engine families as the actual MD-11 plus the RB. 211-600. But, the situation for the manufacturer, and the airline industry in general didn't looked so bright. No new DC-10 orders were received and many, amongst the observers and customers, doubted that the manufacturer would be around for much longer. Thus, the Board of Directors decided in November 1983 to cease once more all work on the projected new trijet.^[1]

The following year, though, things changed. Good times were back and airlines were placing repeat orders for the MD-80s family that had helped the manufacturer to travel through the past difficult years. No new orders for the DC-10 have been received but the production line was nonetheless kept active thanks to a previous order for 60 KC-10A from the USAF. McDonnell Douglas still convinced that a new derivative for the DC-10 was needed as shown by the second hand market of its Series 30 as well as for the heavier DC-10-30ER version. Thus, in 1984 and for the first time, a new derivative aircraft for the DC-10 was designated MD-11. From the very beginning, the MD-11X was conceived in two different versions. The MD-11X-10, based on a DC-10-30 airframe offered a range of 6,500nm (12,038km) with passengers. That first version would have had a MTOW of 580,000lb (263,157kg) and would have used CF6-C2 or PW4000 engines. The MD-11X-20 was to have a longer fuselage, accommodating up to 331 passengers in mixed class layout, and a range of 6,000nm (11,100km).^[1]

As more orders for the DC-10 were received, McDonnell Douglas used the time gained before the end of the DC-10 production, to consult with potential customers and to refine the proposed new trijet. The Board of Directors finally authorized in July 1985 the Long Beach plant to offer the MD-11 to potential customers. At the time, the aircraft was still proposed in two versions, both with the same fuselage length, a stretch of 22ft 3in (6,93m) over the DC-10 airframe, as well as the same engine choice as the MD-11X. One version would have a range of 4,780 nm (8,843km) with a gross weight of 500,000lb (226,680kg) and transport up to 337 passengers, while the second would carry 331 passengers over 6,900nm (12,778km). A year later, as several airlines had committed for the MD-11, the situation was looking optimistic. The aircraft was now a 320 seater baseline and defined as an 18ft 6in (5.66m) stretch over the DC-10-30 powered by the new advanced turbofans offered by the major engine manufacturers and giving it a range of 6,800nm (12,593km). Other versions, such as a shortened ER with a range of 7,500nm, an all cargo offering a maximum payload of 200,970lb (91,077kg) and a Combi with a provision for ten freight pallets on the maindeck, were proposed. Other growth of the aircraft were also foreseen such as the MD-11 Advanced.^[1]

[edit] Development

Finally, the MD-11 was launched on December 30, 1986 with commitments for 52 firm orders^[2] and 40 options^[2] in three different versions (passenger, combi and freighter) from ten airlines (Alitalia; British Caledonian; Dragonair; FedEx; Finnair; Korean Air; Scandinavian Airlines System; Swissair; Thai Airways International and Varig)^[2] and two leasing companies (Guinness Peat Aviation and Mitsui).^[2] Orders from Dragonair, Scandinavian and UTA,^[2] an undisclosed customer, were cancelled by 1988. Assembly of the first MD-11 began on March 9, 1988, and the mating of the fuselage with wings occurred in October that year. First flight was originally planned to occur in March 1989, but numerous problems with the manufacturing, delays with suppliers producing essential components and labor industrial actions led the ceremonial roll out of the prototype to happen only in September that same year. The following months were used to prepare the prototype for its maiden flight, that finally happened on January 10, 1990. The first two aircraft manufactured were intended for FedEx and thus, were already fitted with the forward side cargo door. They remained with the manufacturer as test aircraft until 1991 before being completely converted to freighter and delivered to their customer. FAA certification was achieved by November 8, 1990 while the JAA European Joint Aviation Authorities certified the MD-11 on October 17, 1991 after approximately 200 separate issues were resolved.^[1]

The first MD-11 was delivered to Finnair on December 7, 1990 and accomplished the first revenue service by an MD-11 on December 20, 1990, when the aircraft carried passengers from Helsinki to Tenerife in the Canary Islands. First MD-11 service in the U.S. was inaugurated by Delta Air Lines, also in 1990. It was during this period that flaws in the MD-11's performance began to become apparent. It failed to meet its targets for range and fuel burn.^[3] American Airlines in particular was unimpressed, as was Singapore Airlines, who cancelled its order for 20 aircraft. The airline cited problems with the performance of the airframe and the Pratt & Whitney PW4000 engines selected for its use as reasons of the cancellation.^[4] The figures revealed exclusively to Flight International show that, based on pre-flight estimates, the P&W-powered MD-11 should have been capable of a 7,000 nautical miles (12,950 km) range with 61,000 pounds (27,680 kg) of payload. Even with the Phase 1 drag reduction in place then, the aircraft could only achieve its full range with 48,500 lb (22,000 kg) of payload, or a reduced range of 6,493 nm (12,025 km) with a full payload.^[5]

In 1990, McDonnell Douglas with Pratt & Whitney and General Electric began a modification program known as the Performance Improvement Program (PIP) to improve the aircraft’s weight, fuel capacity, engine performance, and aerodynamics. McDonnell Douglas worked with NASA's Langley Research Center to study aerodynamic improvements.^[6] The PIP lasted to 1995 and recovered the range for the aircraft. However, the damage was already done.^[3]

The MD-11 was one of the first commercial designs to employ a computer-assisted pitch stability augmentation system that featured a fuel ballast tank in the tailplane, and a partly computer-driven horizontal stabilizer. Updates to the software package have achieved a situation where the plane's handling characteristics in manual flight are comparable to the DC-10, despite a much greater fuel efficiency achieved by the lessened drag of the smaller tailplane.

After McDonnell Douglas merged with Boeing in 1997, the new company announced that MD-11 production would continue, as a freighter. However, in 1998 Boeing announced it would end MD-11 production after filling current orders.^[7] The last MD-11 was delivered to Lufthansa Cargo on February 22, 2001. Production ended because of lack of sales, due to internal competition from comparable aircraft, such as the Boeing 777 and external competition from the Airbus A330/A340. Also, two engines are generally less expensive to operate and maintain than three. Since there was a large demand for cargo aircraft and because there was no 777 cargo version available at the time, many airlines using the MD-11 were anxious to switch to the 777 as they had no problems selling their used MD-11s to cargo operators.

McDonnell Douglas and later Boeing performed studies on the feasibility of removing the tail engine and making it a two engine plane, but nothing came of it.^[8][9]

McDonnell Douglas originally projected that it would sell more than 300 MD-11 aircraft, but only a total of 200 planes were built. The MD-11 was assembled at McDonnell Douglas's Douglas Products Division in Long Beach, California (later Boeing's). In August 2006 a total of 191 MD-11 aircraft remain in airline service.^[10]

[edit] Design

The MD-11 is a medium to long-range widebody airliner, with two engines mounted on underwing pylons and a third engine at the base of the vertical stabilizer. It is based on the DC-10, but featuring a stretched fuselage, increased wingspan with winglets, refined aerofoils on the wing and tailplane, new engines and increased use of composites.

The MD-11 features a two-crew cockpit that incorporates six interchangeable liquid-crystal-display units and advanced Honeywell VIA 2000 computers. The cockpit design is called Advanced Common Flightdeck (ACF) and is shared with the Boeing 717. Flight deck features include an Electronic Instrument System, a dual Flight Management System, a Central Fault Display System, and Global Positioning System. Category IIIb automatic landing capability for bad-weather operations and Future Air Navigation Systems are available.

The MD-11 incorporates hydraulic fuses not included in the initial DC-10 design, to prevent catastrophic loss of control in event of a hydraulic failure.

[edit] Variants

The MD-11 was manufactured in five models.

• MD-11 (131 built): the Passenger variant, sometimes referred to as MD-11P, was produced from 1988 to 1998. It was the first version on offer at launch of the aircraft in 1986, and was delivered to: Alitalia (3); American Airlines (19); China Airlines (5); China Eastern Airlines (5); City Bird (3); Delta Airlines (17); EVA Air (3); Finnair (4); Garuda Indonesia (6); Japan Air Lines (10); KLM Royal Dutch Airlines (10); Korean Air (5); LTU International Airways (4); Saudi Arabian Royal Flight (2); Swissair (16); Thai Airways International (4); Varig (6); VASP (6) and World Airways (3).^[11]

• MD-11C (5 built): the Combi was the third variant on offer at launch in 1986 and was designed to accommodate both passengers and freight on the main deck which feature a rear cargo compartement for up to ten pallets accessible by a large rear port side cargo door (160in x 102in - 4.06m x 2.59m) for a main deck cargo volume of 10,904 cubic feet (309 cubic meters). Pallets dimensions are 88in X 125in (2.23m x 3.18m) or 96in x 125in (2.44m x 3.18m). Additional freight is also carried in below deck compartments. The MD-11C can also be configured as an all passenger aircraft. All five aircraft were manufactured between 1991 and 1992 and delivered to Alitalia the only customer for that variant. They have been converted to full freighter in 2005 and 2006 and are still used as such by their original customer.^[11]

• MD-11CF (6 built): the Convertible Freighter variant was launched in 1991 by an order from Martinair for 3 aircraft plus two options. The MD-11CF feature a large forward port side cargo door (140in x 102in - 3.56m x 2.59m) located between the first two passenger doors, and can be used in an all passenger- or in an all cargo-configuration. As a freighter, it can transport twenty six pallets of the same dimensions (88in X 125in (2.23m x 3.18m) or 96in x 125in (2.44m x 3.18m)) as for the MD-11C and MD-11F for a main deck cargo volume of 14,508 cubic feet (411 cubic meters) and offers a maximum payload of 196,928lb (89,325kg). All six MD-11CFs were delivered to Martinair (4) and World Airways (2) during 1995. The two World Airways aircraft have been converted to freighter only in 2002.^[11]

• MD-11ER (5 built): the Extended Range version was launched by the manufacturer at the Singapore Air Show in February 1994.^[2] The MD-11ER incorporates all the Performance Improvement Program (PIP) options, including a Maximum Take-Off Weight of 630,500 lb (285,990 kg) and an extra fuel tank of 3,000 US gallon (11,356 liters) in the forward cargo hold^[12] to offer a range of 7,240 nm (13,408 km), an increase of 400 nm (753 km) over the standard passenger variant. MD-11ERs were delivered between 1995 and 1997 to Garuda Indonesia (3) and World Airways (2). As off February 2007, one MD-11ER has been deconverted to MD-11 with the removal of the extra fuel tank. This aircraft is in service with Finnair.^[11]

• MD-11F (53 built): the Freight transport aircraft was the second variant on offer at launch in 1986 and was the last and longest (1988-2000) manufactured version. The all-cargo aircraft features the same forward port side cargo door (140in x 102in - 3.56m x 2.59m)as the MD-11CF, a main deck volume of 15,530 cubic feet (447 cubic meters), a maximum payload of 200,151lb (90,787kg) and can transport twenty six pallets of the same dimensions (88in X 125in (2.23m x 3.18m) or 96in x 125in (2.44m x 3.18m)) as for the MD-11C and MD-11CF. The MD-11F was delivered between 1991 and 2001 to China Eastern Airlines (1); EVA Air (9); FedEx Express (22); Lufthansa Cargo (14); Martinair (2); Saudi Arabian Airlines (4) and World Airways (1).^[11]

Nota Bene : Some or all the features of the MD-11ER, including the higher MTOW of 630,500 lb (285,990 kg), part or all of the PIPs aerodynamic improvements packages and composite panels were fitted to later built MD-11s (except the extra fuel tank), and could be retrofited to any of the variants, except for the PIP Phase IIIB larger aft engine intake. Some airlines, such as Finnair, Martinair and FedEx have made the structural changes required to allow their aircraft to have the higher MTOW. Swissair 16 newly delivered aircraft were retrofited with all the features except for the extra fuel tank and were so-designated MD-11AH for Advanced Heavy.^[11]

[edit] Operators

[edit] Passenger

Most of the airlines (American Airlines, China Airlines, China Eastern Airlines, Delta Air Lines, Finnair, Garuda Indonesia, Japan Airlines, KLM Royal Dutch Airlines, Korean Air, LTU International, Swissair, Thai Airways International, Varig & VASP) having ordered the MD-11 for their long-haul regular or charter passenger flights have replaced their fleet of the type with Airbus A330, A340 as well as Boeing 777 by the end of 2004, or in some case converted their MD-11s to freighters such as China Eastern and Korean Air. The South Korean airlines announced as early as December 1994 its intention to remove the MD-11 from its passenger services and to use its five aircraft on medium-range cargo routes^[13] less than four years after the first delivery. One year later, American Airlines signed an agreement to sell its nineteen aircraft to FedEx with the first leaving the fleet in January 1996.

In October 2006, TAM Linhas Aéreas announced an order of four 777-300ER, expected to be delivered in 2008. In the meantime, the airline decided to lease three MD-11s for its intercontinental services.

As of March 2007, the only airlines still operating MD-11s on their regular intercontinental flights are: Finnair (7), KLM Royal Dutch Airlines (10), TAM Linhas Aéreas (2) and VRG Linhas Aereas (2). World Airways is also operating 6 MD-11s, mainly for the Air Mobility Command, of which three are former Delta Airlines aircraft now leased from United Parcel Service until their conversion to freighter, as well as two MD-11ERs, one of which is dedicated and specially configured for the "Houston Express", SonAir's three times weekly service between Houston and Luanda in Angola.^[14]

[edit] Cargo

• Alitalia (5) - The Italian carrier has converted the five former MD-11C it had in its fleet.
• China Cargo Airlines (6) - This is a joint venture between China Eastern Airlines and China Ocean Shipping utilizing six former China Eastern aircraft.
• EVA Air Cargo (10) - Two member of the fleet are previously passenger MD-11s and converted to freighter in 2003.
• FedEx Express (58) - The fleet is composed of 21 newly delivered aircraft and 37 second hand passenger aircraft converted to freighter coming from American Airlines, China Airlines, Delta Airlines and Swiss International Airlines.
• Gemini Air Cargo (4) - The first two received in 2000 are former Varig aircraft, while the last two are former VASP planes.
• Lufthansa Cargo (19) - This airline was the last major to order MD-11s and received 14 of the freighter, including the very last MD-11 produced. In 2004 and 2005 it added to its fleet five former Alitalia (3) and Varig (2) passenger aircraft after having them converted to freighter.
• Martinair (7) - The Dutch company trijet fleet is composed of four MD-11CF currently used only for cargo flights, as well as two newly delivered MD-11Fs and a former Swiss MD-11 converted to freighter.
• Saudi Arabian Airlines (4) - All newly delivered in December 1997 and January 1998.
• Shanghai Airlines (2) - The Pudong International Airport based airline is currently utilizing two former EVA Air MD-11Fs.
• Transmile Air Services (4) - The Malaysian airline fleet is composed of four former Swiss/LTU passenger aircraft converted to freighter.
• United Parcel Service (24) - UPS fleet of MD-11Fs is exclusively composed of second hand passenger aircraft converted having previously served with Delta Airlines, Thai Airways International, Swissair, VARIG, VASP and World Airwas. As off March 2007, 24 are in service while 14 additional are to enter the fleet by 2008.
• World Airways (6) - Of the six aircraft only one was built as freighter. Two were previously MD-11CFs and converted in 2002, two are former Korean Air aircraft, while the last one is the next to last MD-11 passenger built and converted to freighter in October 2006.^[15] World is currently operating two MD-11Fs for Air Canada^[16] and two for Lufthansa Cargo.^[17]

[edit] Previous operators

Former operators with highest number of aircraft for each in parentheses.^[18]

[edit] Accidents

As of February 2007, there have been five MD-11 hull-loss accidents.

FedEx lost an MD-11 (N611FE) during a landing incident at Newark International Airport when Flight 14 crashed on July 31, 1997. The aircraft flipped onto its back and subsequently burned, following a landing attempt from an unstabilized flare.

Swissair Flight 111, an MD-11 (HB-IWF), crashed on September 2, 1998. The cause of the crash was determined to be a fire caused by improper wiring of Swissair-added passenger entertainment system units. The fire started at the front of the aircraft and quickly grew uncontrollable, attributed partly to the poor flame retardant properties of its metalized mylar insulation.

Korean Air MD-11F HL7373 crashed shortly after take off April 15, 1999 while operating cargo flight KE6316 from Shanghai Honqiao Airport airport to Seoul. After take off, the first officer contacted Shanghai Departure, which cleared the flight to climb to 1500 meters (4900 feet): "Korean Air six three one six now turn left direct to November Hotel Whiskey climb and maintain one thousand five hundred meters." When the aircraft climbed to 4500 feet in the corridor, the captain, after receiving two wrong affirmative answers from the first officer that the required altitude should be 1500 feet, thought that the aircraft was 3000 feet too high. The captain then pushed the control column abrubtly and roughly forward causing the MD-11 to enter a rapid descent. Both crew members tried to recover from the dive, but were unable.^[19]

China Airlines Flight 642 crashed August 22, 1999 while landing at Hong Kong airport during a typhoon that exceeded the plane's crosswind specifications, also flipping onto its back and burning. Three passengers were killed on flight 642.

FedEx MD-11F N581FE was written off after landing at Subic Bay International Airport October 17, 1999. The aircraft was operating flight 87 from Shanghai Honqiao Airport. Upon landing, the aircraft rolled down the whole length of the runway before plunging into the bay where it was completely submerged except for the cockpit. An excessive approach and landing speed was pointed out as probable cause of the accident.^[20]

[edit] Specifications

	MD-11 (Passenger)	MD-11CF (Convertible Freighter)	MD-11F (Freighter)	MD-11C (Combi)	MD-11ER (Extended Range)
Passengers	410 (1 class) 323 (2 class) 293 (3 class)	410 (1 class) 323 (2 class) 293 (3 class)	n/a	410 (1 class) 214 (2 class) 181 (3 class)	410 (1 class) 323 (2 class) 293 (3 class)
Max takeoff weight *	standard: 602,500 lb (273,366 kg) heavy: 630,500 lb (285,990 kg)	standard: 625,000 lb (283,575 kg) heavy: 630,500 lb (285,990 kg)	standard: 610,000 lb (276,769 kg) heavy: 630,500 lb (285,990 kg)	standard: 610,000 lb (276,769 kg) heavy: 630,500 lb (285,990 kg)	630,500 lb (285,990 kg)
Max landing weight	430,000 lb (195,045 kg)	471,500 lb (213,872 kg) optional: 481,000 lb (218,405 kg)	481,500 lb (218,405 kg)	458,000 lb (207,745 kg)	481,500 lb (218,405 kg)
Operating empty weight	283,975 lb (128,808 kg)	288,296 lb (130,768 kg)	248,567 lb (112,748 kg)	283,975 lb (128,808 kg)	291,120 lb (132,049 kg)
Max range	6,840 nm (12,655 km)	Pass: 6,840 nm (12,655 km) Freight: 3,950 nm (7,310 km)	3,950 nm (7,310 km)	6,720 nm (12,435 km)	7,240 nm (13,408 km)
Max cruising speed	0.88 Mach (945 km/h / 520 kt)
Length	200 ft 11 in (61.23 m) with Pratt & Whitney engines 201 ft 4 in (61.36 m) with General Electric engines
Wingspan	169 ft 6 in (51.66 m)
Wing area (Including winglets)	3,648 square feet (339 square meters)
Tail height	57 ft 9 in (17.60 m)
Engines (3x)	Pratt & Whitney PW4460 - 60,000 lbf (267 kN) PW4462 - 62,000 lbf (276 kN) General Electric CF6-80C2D1F - 61,500 lbf (274 kN)

Notes: *Heavy refers to aircraft with Extended Range option and aircraft incorporating the same drag reduction and structural modifications options, except for the additional fuel tank, and are available on all models. Standard refers to basic original configuration.

Sources:^{[1][21][22][11]}

[edit] References

[edit] External links

• MD-11 page on Boeing.com
• MD-11 history page on Boeing.com
• MD-11 on airliners.net
• Kev's MD-11 site

[edit] Related content

Related development

• McDonnell Douglas DC-10
• McDonnell Douglas MD-12

Comparable aircraft

• Lockheed L-1011
• Boeing 777
• Airbus A340
• McDonnell Douglas DC-10

Related lists

• List of airliners

See also