The McDonnell Douglas company spent a lot of time researching to create an aircraft that could become a worthy successor to the DC-10. However, for some reason, the new MD-11, although it absorbed the latest technology, could not become a successful commercial project.
McDonnell Douglas, as a tradition, took the existing airliner – DC-10 as the basis for creating a new MD-11 aircraft. The new aircraft was supposed to become larger, with a longer range, modern engines, and digital avionics. Work on such a liner was launched back in 1978 – in response to wishes from McAir to get a longer version of the DC-10. It was planned to put the new aircraft into operation in the early 1980s, creating competition for the American Boeing 747 and leading the European concern Airbus.
The modified DC-10 Series 60 was offered in three versions: DC-10-61 – an option for the intra-American market, which integrated the wing from the DC-10-30 and the larger and heavier fuselage; DC-10-62 – a transatlantic airliner with a shorter fuselage and an extended wing with wings; and DC-10-63 – an option with a wing from Series 62 and a fuselage from Series 61. Moreover, each of these options was larger than the MD-11, although the maximum take-off weight was approximately the same. But soon McAir’s interest in Series 60 airliners began to fade, and with the start of rising fuel prices it completely disappeared – the company now needed a completely new plane.
In 1982, the MD-100 project was announced. The aircraft retained the three-engine layout of the power plant and remained in the dimensions of DC-10, but received a cockpit for two pilots and new engines – Pratt & Whitney PW2037 or Rolls-Royce RB211-535 (both were placed on the Boeing 757). However, like Series 60, the MD-100 did not cause much interest among customers. McDonnell Douglas continued to work on a new airliner, and in 1984 the MD-XXX appeared – the aircraft was slightly larger than the DC-10-30 and was powered by General Electric CF6-80C2 or Pratt & Whitney PW4000 engines. It was also proposed to lengthen the fuselage. By the end of the year, the new liner was assigned the designation MD-11.
The MD-11 family included the following modifications: MD-1IX-10ER – with a DC-10 dimension fuselage, as well as the MD-11X-20 and MD-11X-MR with 6.7 m elongated fuselages. In July 1985, the board of directors of McDonnell Douglas approved the launch of the MD-11 program – an official start of sales was scheduled for early 1986. The market for MD-11 was expected to be 1,400 vehicles, of which at least 300 could be purchased by McAir. The first deliveries were expected in 1989.
By October 1985, several changes were made to the MD-11 project (including the lengthening of the fuselage not by 6.7 m, but by 5.7 m), the composition of the family also changed: the MD-11X-MR did not arouse interest and was closed in development, then soon the same fate befell MD-11X-10ER. The cockpit for two pilots and the possibility of installing CF6-80C2 or PW4000 engines were preserved, and the maximum take-off weight was set to 273,294 kg.
The official start of the MD-11 program was given on December 30, 1986 – McDonnell Douglas confirmed the availability of 82 orders from 12 companies. However, only a few of them were solid, and subsequently, some of them were canceled. By the end of 1987, the order portfolio totaled 30 firm orders and 47 in the form of “acquisition intentions”. No major orders have been received from major US carriers. Sales of the cargo modification MD-11 were more successful (two variants of the “truck” were offered to orderers).
The basic version of the MD-11 was built based on the DC-10-30 fuselage – with two inserts in the front and behind the wing, the fuselage section – like on the DC-10. The length of the MD-11 was 61 meters with Pratt & Whitney engines and 61.3 meters with General Electric engines. The aircraft turned out to be 1.37 m longer than the DC-10, although both liners are structurally similar in general. A distinctive feature was the winglets made of aluminum alloy and composites, which protruded 2.13 m above the wing and 0.76 m below it. According to the calculations of the engineers of the developer company, the winglets reduced drag by 4%.
MD-11 received a new tail unit of lower sweep and area, which also reduced drag. The power plant options included General Electric CF6-80C2D1F engines with a thrust of 273.6 kN or a Pratt & Whitney PW4460 with a thrust of 270 kN. Rolls-Royce offered it’s Trent 665 for the MD-11, but the only customer for this option – Air Europe – ceased to exist in 1991, even before deliveries began.
Instrumentation pilot cabin MD-11 included six indicators and a new flight control system.
In the one-class layout, the MD-11 cabin contained 405 seats, in the two-class layout – 323 seats, and in the three-class layout – 293 seats.
From the very beginning, the MD-11 aircraft project did not bring significant orders to the developer. Even the relatively successful freight option did not save the program – in 2000, the assembly line was closed.
The MD-11 program was officially launched on December 30, 1986 – at that time there were 92 pre-orders from 12 customers, including the British Caledonian, Dragonair, SAS, and the Mitsui & Company leasing company. There were fewer firm orders, and the SAS and Dragonair agreements of intent, for example, were never implemented, and a firm order from British Caledonian was canceled after the acquisition of the British Airways company.
As a result, in 1986 only 11 firm orders were received at MD-11: from Mitsui & Co. – five, from Korean Airlines – four, from the GPA – two aircraft. The following orders appeared in March – April 1987: Finnair (two aircraft), Swissair (six, and an order for four more placed in December), Alitalia (one). The latter company became the starting customer for the MD-11C Combi – the order included five machines, while Federal Express (FedEx) – became the starting customer for the MD-11F Freighter, ordering two cars.
In March 1988, at the time the final assembly of the first MD-11 began, the order portfolio totaled only 31 aircraft, plus the developer announced that, due to delays in the supply of components, the delivery of the first machine was postponed to February 1989, and its first flight to April. During 1988, McDonnell Douglas received orders from the following companies: Thai International (four aircraft), Federal Express (two), China Airlines (four), Delta Air Lines (nine), China Eastern “(four, plus one MD-1 IF),” Finnair “(two),” Garuda “(six), 1LFC (three, plus two MD-11 F), LTU (three) and VAR1G (four). The order from Delta was at that time the most important since it included nine firm orders and an option for 31 aircraft. Also, it was the first major order for the MD-11 from an American airline.
In 1989, the receipt of orders continued. Orders were placed: Federal Express (two MD-11F), Swissair (two), American Airlines (15), LTU (one), and EVA Air (two plus three MD-11F). Moreover, American Airlines subsequently became the largest passenger operator of the MD-11, and Air Europe, which placed an order for the MD-11 in 1989, preferred the Trent 665 engines, although it had gone out of business even before the aircraft began to be delivered.
Another unsuccessful customer was Air Zaire, which announced its intention to order several cars, which in reality did not materialize.
The first MD-11 was deflated on November 6, 1989, and on January 10, 1990, it made its first flight — eight months later than originally planned. The aircraft, equipped with CF6 engines, embarked on a flight test program in which five aircraft flew about 2000 hours. Moreover, to accelerate the test program, McDonnell Douglas certified MD-11 as a variant of DC-10, and not as a completely new type of aircraft. The FAA type certificate was obtained on November 30, 1990, and on December 19 was certified MD-11 with PW4460 engines.
The first MD-11 was delivered to the customer, Finnair, on November 29, 1990, although a different date was specified in the contract – December 7. Finnair put the aircraft into commercial operation on December 20, 1990 – on the Helsinki-Tenerife line. The very first aircraft with PW4460 engines was delivered to Korean Airlines on January 25, 1991.
1990 was a successful year for the MD-11 program – rather large orders were received from such companies as American Airlines (11 aircraft), KLM (10), Japan Airlines (10), Korean Airlines (one), Federal Express (two MD-1 IFs), Delta Air Lines (two) and GATX Capital (one). But next year, the number of orders was small: Delta Air Lines (two aircraft), Federal Express (five MD-1 IF), and Marti-nair Holland (three MD-11F).
The reason for the drop in demand was revealed quickly – the plane experienced various problems, some characteristics did not satisfy the operators. The aircraft had worse than planned payload and range, as well as low fuel efficiency. In MD-11 advertising booklets, the maximum flight range with 293 passengers and a payload of 27,670 kg was indicated as 12,955 km, but even before the end of the flight test program, McDonnell Douglas understood that this indicator could not be achieved.
One of the main reasons was the lower fuel efficiency of both engine variants – 4-9% worse than the values specified in the contracts. There were other shortcomings, to eliminate which the developer launched a program to improve the performance of the airliner, during which it was necessary to redesign the wing and some other structural elements of the machine, as well as reduce its weight. Among other things, this allowed to reduce aerodynamic drag and increase the capacity of the fuel system. Both of their developers completed the corresponding refinement of their engines, and Delta Air Lines developed the option of installing an additional fuel tank in the luggage compartment – in exchange for two LD3 cargo containers.
By 1996, McDonnell Douglas concluded that further improvement in performance without serious reworking of the airframe was no longer possible, but overall, the machine reached its original range. However, damage to the program has already been done. For example, an order from Singapore Airlines for 20 airplanes was lost, and since 1992 the flow of orders has slowed down significantly – companies took only one or two airplanes.
In the mid-1990s, McDonnell Douglas announced several modernization programs for the MD-11, including twin-engine and longer-range modifications. In 1994, the MD-11ER was announced as the “300-seat airliner with the longest flight range.” Able to deliver 298 passengers at a distance of at least 13,350 km, the MD-11ER was created as a direct competitor to the Boeing 777 and Airbus A340.
However, interest in the base case has already fallen significantly, so the new proposals have not aroused active interest. The MD-11ER project “died” shortly before the Boeing was acquired by McDonnell Douglas in August 1997, whose management announced in June 1998 that all versions of the MD-11 would be discontinued in 2000. By May 2000, the MD-11 portfolio of orders included 200 machines, of which 197 were delivered to customers. The last three MD-11Fs were handed over to Lufthansa Cargo the same year, and the MD-11 came to an end.
- MD-11: first production modification
- MD-11P: a pure passenger version, can carry 293 people at a distance of 11,000 km or 405 passengers in an economy class cabin; began to be operated in 1986.
- MD-11 Combi: combined passenger and cargo option, can carry 176 passengers and six cargo containers (in the rear compartment) on the main deck and additional cargo in the lower compartments; has a cargo door that opens upward, measuring 4×3 m. Put into operation in April 1987.
- MD-11F: a pure cargo version with a cargo door measuring 3.5×3 m in front of the wing on the left side of the fuselage, without doors and portholes for passengers, can carry up to 102 tons of cargo. It was commissioned in May 1987.
- MD-11CF: passenger-freight option. Doors and portholes for passengers saved. It was put into operation in August 1991.
- Modification: MD-11
- Wingspan, m: 51.60
- Length, m: 61.20
- Height, m: 17.60
- Wing Area, m2: 338.90
- Weight kg: empty loaded aircraft 125870; maximum take-off 277300
- Engine type: 3 turbofan engine General Electric CF6-80C2D1F (Pratt Whitney PW4460)
- Draft, kgs: 3 x 273 (267)
- Maximum speed, km / h: 962
- Cruising speed, km / h: 912
- Economic speed, km / h: 876
- Practical range, km: 9270
- Practical ceiling, m: 9935
- Crew: 2
- Payload: 293 passengers in the mixed class or 405 passengers in the economy class cabin or up to 102,000 kg of cargo.