McDonnell Douglas MD-11

The McDonnell Douglas MD-11 is a widebody aircraft powered by three engines. It is based on the DC-10, but featuring a stretched fuselage, more wingspan with winglets, refined aerofoils on the wing and tailplane, new engines, extensive use of composites, and a crew of two (rather than three on the DC-10), all-digital glass cockpit. It also included hydraulic fuses not previously designed on DC-10s, to prevent catastrophic loss of control in the event of a hydraulic failure.

Probably the biggest impediment to sales of the MD-11, despite its high-tech improvements and hard work from engineers, was that it was haunted by the problems of the DC-10

History

The MD-11 program was launched on December 30, 1986, with orders and commitments for 92 aircraft from 12 airlines and leasing companies. Assembly of the MD-11 began on March 9, 1988, with the first flight of an MD-11F (freighter version) on Jan. 10, 1990. FAA certification was achieved by Nov. 8, 1990. The first MD-11 was delivered to Finnair on Dec. 7, 1990. Finnair's first revenue service with the MD-11 occurred 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 began to appear with the MD11's performance. It failed to meet its targets for range and fuel burn, and American Airlines in particular was unimpressed; as was Singapore Airlines, who cancelled their order for 20 aircraft in favor of the Airbus A340, which itself was later displaced by the Boeing 777. Although improvements were made and the aircraft did eventually perform as designed, the damage was done.

After McDonnell-Douglas was acquired by Boeing in 1997 the new company announced that MD-11 production would continue, primarily as a freighter. However a year later Boeing announced it would cease MD-11 production. 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 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 did perform studies on the feasibility of removing the 3rd tail engine and making it a 2 engine plane, but nothing came of it.

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 the Douglas Products Division of Boeing in Long Beach, California.

Operators

American Airlines and Delta Air Lines used MD-11's for intercontinental flights during the 1990s, but have since sold their fleets to FedEx. Current operators include Alitalia, China Eastern, EVA Air, Finnair, Gemini Air Cargo, KLM, Lufthansa Cargo, Martinair, Air Namibia, Northwest Airlines (Asian Routes), Northwest Cargo, Varig, United Parcel Service, and World Airways.

Incidents and accidents

Swissair Flight 111, which crashed on September 2, 1998, was an MD-11. 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.

FedEx lost an MD-11 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 unstabilised flare. A similar accident happened in 1999, when China Airlines Flight 642 crashed 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. Some have said that the tailplane of the MD-11 design is too small considering the stretched fuselage length compared to the DC-10, but this claim has never been substantiated by any official investigative body or aviation authorities. 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 stabiliziser. 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.

Specifications

The MD-11 was manufactured in four versions: passenger, all freighter, convertible freighter and combi, where passengers and freight are carried on the main deck with additional freight carried below the deck.

Depending on configuration, the MD-11 can carry from 285 to 410 passengers. Fully loaded, the MD-11 airliner has a range of 7,630 miles (12,270 km), while carrying 285 passengers and their baggage.

	MD-11 (Passenger)	MD-11-F (Freighter)	MD-11-C (Combi)	MD-11-ER (Extended Range)
Passengers (1 class)	410	.	.	.
Passengers (2 class)	323	.	204	.
Max. takeoff weight	602,555 lb (273,314 kg)	602,555 lb (273,314 kg)	620,350 lb (283,700 kg)	630,500 lb (285,990 kg)
Max range	6,821 nm (12,633 km)	3,910 nm (7,242 km)	6,691 nm (12,392 km)	7,240 nm (13,408 km)
Max cruising speed	945 km/h (510 kt)
Length	61.21 m (200 ft 10 in)
Wingspan	51.66 m (169 ft 6 in)
Tail height	17.60 m (57 ft 9 in)
Engines	Three 267 kN (60,000 lbf) Pratt & Whitney PW4460s, three 276 kN (62,000 lbf) PW4462s, or three 274 kN (61,500 lbf) General Electric CF6-80C2D1F turbofans.

Sources

Airliners.net:McDonnell Douglas MD-11

U.S. airliners 1990-1999

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History

Operators

Incidents and accidents

Specifications

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