| abstract
| - 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 (12.19 m) and a DC-10-30 stretched by 30 ft (9.14 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. While continuing its research 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 26' 8" (8.13 m) 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. 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 ft (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 unfortunately stopped. This classic plane had all that was needed to become a comercial success, but came into the market at the same time as many strong competitors (e.g. B777 and A330). In 1981, a Continental Airlines DC-10-10 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 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 (6.24 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. The following year, though, things changed. Good times were back and airlines were placing repeat orders for the MD-80 series jets that had helped the manufacturer to travel through the past difficult years. No new orders for the DC-10 had been received, (which inspired McDonnell Douglas even more to create a replacement) but the production line was nonetheless kept active thanks to a previous order for 60 KC-10A tankers from the USAF. McDonnell Douglas was 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 6,500 nmi (12,038 km) with passengers. That first version would have had a Maximum Take-Off Weight (MTOW) of 580,000 pounds (263,157 kg) 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 a mixed class layout, and a range of 6,000 nmi (11,100 km). 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 (6.93 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 nmi (8,840 km) with a gross weight of 500,000 lb (227,000 kg) and transport up to 337 passengers, while the second would carry 331 passengers over 6,900 nmi (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 6 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 nmi (12,600 km). Other versions, such as a shortened ER with a range of 7,500 nm (13,900 km), an all cargo offering a maximum payload of 200,970 lb (91,080 kg) and a Combi with a provision for ten freight pallets on the maindeck, were proposed. Further growth of the aircraft was also foreseen, such as the MD-11 Advanced.
|
![[RDF Data]](/fct/images/sw-rdf-blue.png)