McDonnell Douglas MD-11
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| MD-11 | |
|---|---|
 | |
| KLM MD-11 departing Amsterdam Airport Schiphol | |
| Role | Wide-body jet airliner |
| National origin | United States |
| Manufacturer | McDonnell Douglas/Boeing |
| First flight | January 10, 1990 |
| Introduction | December 1990 with Finnair |
| Status | Out of production, in service |
| Primary users | FedEx Express UPS Airlines World Airways Lufthansa Cargo |
| Produced | 1988–2000 |
| Number built | 200 |
| Developed from | McDonnell Douglas DC-10 |
Contents |
Development
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 40 feet (12 m) and a DC-10-30 stretched by 30 feet (9.1 m). That later version would have been capable of transporting up to 340 passengers in a multi-class configuration, or 277 passengers and their luggage over 5,300 nautical miles (9,800 km). At the same time, the manufacturer was searching to reduce wing and engine 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]
Following more refinements, the DC-10 Super 60 project was proposed, as of 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 feet (12 m). Like for the DC-8, the series 62 was proposed as an intercontinental aircraft stretched by 26 ft 7 in (8.10 m) 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 Flight 191, Western Airlines Flight 2605 and Air New Zealand Flight 901) which received great media coverage, the trijet program was seriously damaged by doubts regarding its structural integrity. For these reasons, and due to another downturn in the airline industry, all work on the Super 60 was stopped.[1]
In 1981, a Continental Airlines DC-10-10 (registration number N68048) was leased to conduct more research and particularly the effects the then newly-designed winglets could have on aircraft performance. Different types of winglets were tested during that time in conjunction with 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 rationalized all these studies under the MD-EEE (Ecology-Economy-Efficiency) 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 6 ft 6 in (1.98 m) 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 20 ft 6 in (6.25 m) 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, did not look bright. No new DC-10 orders were received, and many among 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]
As more orders for the DC-10 were received, McDonnell Douglas used the time gained before the end of DC-10 production to consult with potential customers and to refine the proposed new trijet. In July 1985, the Board of Directors finally authorized 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 22 ft 3 in (6.78 m) 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 nautical miles (8,850 km) with a gross weight of 500,000 pounds (230,000 kg) and transport up to 337 passengers, while the second would carry 331 passengers over 6,900 nautical miles (12,800 km). 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 18 ft 7 in (5.66 m) stretch over the DC-10-30 powered by the new advanced turbofans offered by the major engine manufacturers and giving it a range of 6,800 nautical miles (12,600 km). Other versions, such as a shortened ER with a range of 7,500 nautical miles (13,900 km), an all cargo offering a maximum payload of 200,970 pounds (91,160 kg) and a Combi with a provision for ten freight pallets on the main deck, were proposed. Further growth of the aircraft was also foreseen, such as the MD-11 Advanced.[1]
Design phase
Yugoslav Airlines, which was already flying several DC-10s, was to become the first customer of the MD-11. Three aircraft were manufactured but were never delivered due to war in Yugoslavia. The first MD-11 was delivered to Finnair on December 7, 1990 and it accomplished the first revenue service by an MD-11 on December 20, 1990, carrying passengers from Helsinki to Tenerife in the Canary Islands. 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 became apparent. It failed to meet its targets for range and fuel burn.[3] American Airlines in particular was unimpressed, as was Singapore Airlines, who canceled their order for 20 aircraft. American Airlines cited problems with the performance of the airframe and the Pratt & Whitney PW4000 engines as reasons of the cancellation while the Singapore Airlines stated that the MD-11 could not operate on the airline's long haul routes.[4] Pre-flight estimates indicated that the P&W-powered MD-11 was to have a 7,000 nautical miles (13,000 km) range with 61,000 pounds (28,000 kg) of payload. With the Phase 1 drag reduction in place then, the aircraft could only achieve its full range with 48,500 pounds (22,000 kg) of payload, or a reduced range of 6,493 nautical miles (12,025 km) with a full payload.[5]
In 1990, McDonnell Douglas, along 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 until 1995 and recovered the range for the aircraft. However, by this point sales of the MD-11 had already been significantly impacted.[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 made the plane's handling characteristics in manual flight similar to the DC-10, despite a smaller tailplane to reduce drag and increase fuel efficiency.
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.[9][10] McDonnell Douglas originally projected that they would sell more than 300 MD-11 aircraft, but only 200 planes were built. The MD-11 was assembled at McDonnell Douglas's Douglas Products Division in Long Beach, California (later Boeing's facility).
Design
The MD-11 features a two-crew cockpit that incorporates six interchangeable CRT-units and advanced Honeywell VIA 2000 computers. The cockpit design is called Advanced Common Flightdeck (ACF)[11] 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.[11]
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.[14]
Variants
- 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 American Airlines (19), Delta Air Lines (17), Swissair (16), Japan Air Lines (10); KLM (10), and other airlines with fewer aircraft.[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 featured a rear cargo compartment for up to ten pallets, each measuring 88 by 125 inches (2.2 × 3.2 m) or 96 by 125 inches (2.4 × 3.2 m). The main deck cargo compartment was accessible by a large rear port side cargo door, which measured 160 by 102 inches (4.1 × 2.6 m). The main deck cargo volume was 10,904 cubic feet (308.8 m3). Additional freight was also carried in below-deck compartments. The MD-11C could 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.[11] In 2005 and 2006 the airline converted them to full-freighter configurations to be operated by Alitalia's cargo division. Following that division's closure, the five aircraft were returned to their lessor in January 2009.[15]
- 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 (140 by 102 inches (3.6 × 2.6 m)) 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 (88 by 125 inches (2.2 × 3.2 m)) or 96 by 125 inches (2.4 × 3.2 m)) as for the MD-11C and MD-11F for a main deck cargo volume of 14,508 cubic feet (410.8 m3) and offers a maximum payload of 196,928 pounds (89,325 kg). 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 pounds (286,000 kg) and an extra fuel tank of 3,000 US gallons (11,000 l)) in the forward cargo hold[16] to offer a range of 7,240 nautical miles (13,410 km), an increase of 400 nautical miles (740 km) over the standard passenger variant. MD-11ERs were delivered between 1995 and 1997 to Garuda Indonesia (3) and World Airways (2). As of February 2007, only one Finnair MD-11ER has been converted to MD-11 with the removal of the extra fuel tank.[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 (140 by 102 inches (3.6 × 2.6 m)) as the MD-11CF, a main deck volume of 15,530 cubic feet (440 m3), a maximum payload of 200,151 pounds (90,787 kg) and can transport 26 pallets of the same dimensions (88 by 125 inches (2.2 × 3.2 m) or 96 by 125 inches (2.4 × 3.2 m)) as for the MD-11C and MD-11CF. The MD-11F was delivered between 1991 and 2001 to FedEx Express (22), Lufthansa Cargo (14), and other airlines with fewer aircraft.[11]
- MD-11 Boeing Converted Freighter (BCF) - Boeing and its group of international affiliates offer a conversion of used passenger airliners into freighters. The MD-11BCF is one of the models offered.[17]
Operators
In July 2011, 181 MD-11 aircraft (all variants) were in commercial service, with FedEx Express (63), UPS Airlines (38), Lufthansa Cargo (18), World Airways (16), KLM Royal Dutch Airlines (10), EVA Air (8), and other operators with fewer aircraft of the type.[18]
In February 2007 TAM Linhas Aéreas began operating the first of three leased MD-11s in intercontinental service following a 2006 order for four 777-300ERs to be delivered in 2008.[21] In May 2007, Finnair announced the sale of their last two MD-11s to Aeroflot-Cargo to become part of the Russian airline cargo fleet in 2008 and 2009.[22] Varig retired the MD-11 from its fleet in June 2007 after sixteen years of services.[citation needed]
Two MD-11s were also operated in a VIP configuration, one by Saudi Arabian Airlines Royal Flight[23] for members of the Royal family, and one by Mid East Jet for ASACO Aviation, both are now stored.[24]
Current operators
MD-11 are operated by the following airlines as of February 2012:- Current passenger operators
- KLM (10) - is the last airline operating MD-11s on regular intercontinental flights in 2012. Operation will end in winter 2015.
- World Airways (7) - is also operating five MD-11s and two MD-11ERs for passenger transport.[25][26][27]
- Current cargo operators
- Aeroflot-Cargo (3)[28] - The Russian airline was to receive at least six MD-11F in 2008. Two aircraft are currently stored.[29]
- Avient Aviation (1) - This airline lost an MD-11F in Shanghai.
- Centurion Air Cargo (4)[28] - The Miami-based company specialized in Aircraft, Crew, Maintenance and Insurance (ACMI) wet-leases, now operates a fleet of two freighters, one being a former Gemini Air Cargo, and the latest a former Alitalia aircraft.[30]
- Ethiopian Airlines (1) has received its first MD-11F on January 31, 2009.[31]
- China Cargo Airlines (3)[28] - The former MD-11F operator are back to flying three ex-Shanghai Airlines Cargo aircraft, gained from merger of the carrier in 2011.
- Etihad Crystal Cargo (2) - leased from/operated by World Airways, not in Etihad colours.
- EVA Air Cargo (9)[28]
- FedEx Express (59)[28] - Fleet consists of 21 newly delivered aircraft and 38 second hand passenger aircraft converted to freighter coming from American Airlines, China Airlines, Delta Air Lines and Swiss International Airlines. The express carrier is to add two former TAM aircraft to its fleet, both previously intended for Aeroflot Cargo and Ethiopian Airlines.[32]
- Lufthansa Cargo (19)[28] - 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 Cargo (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.
- Nordic Global Airlines (2 + 1 leased from World) - operated in Own livery.
- Saudi Arabian Airlines (4)[28] - All newly delivered from December 1997 to January 1998 and operated on flights to Addis Ababa, Bangkok, Brussels, Hong Kong, Khartoum and Shanghai.[33]
- UPS Airlines (38)[28] - UPS fleet of MD-11Fs is exclusively composed of second hand passenger aircraft converted having previously served with Delta Air Lines, Japan Air Lines, Thai Airways International, Swissair, VARIG, VASP and World Airways.
- World Airways (15)[28] - Of its 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.[34] The Peachtree City-headquartered airline has now added three more MD-11Fs, all formerly part of Gemini Air Cargo fleet.[35]
Former operators
Former operators with highest number of aircraft for each in parentheses.[25][32][36]- Former passenger operators
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- Former cargo operators
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Safety issuesThe MD-11 has had problems with its flight control systems, problems that have resulted in multiple accidents and incidents since the aircraft's introduction.[49] The initial design of the slat/flap lever in the cockpit was conducive to accidental dislodgement by crew in flight. The defect has been corrected since 1992.[50] In the early 2000s, Boeing improved the flight control software at the urging of the FAA to reduce the possibility of violent unintentional pitch movements.[49]In an effort to improve fuel efficiency, McDonnell Douglas designed the MD-11’s center of gravity to be much further aft than other commercial aircraft. This significantly reduces the margin for error during the takeoff and landing phases. A number of operators have introduced special training to assist crews in safely handling the MD-11's critical phases of flight.[51] Specifications
Sources:[1][11][52][53] Deliveries
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