The McDonnell Douglas MD-12 was a large

wide-body airliner A wide-body aircraft, also known as a twin-aisle aircraft, is an airliner with a fuselage wide enough to accommodate two passenger aisles with seven or more seats abreast. The typical fuselage diameter is . In the typical wide-body economy cabin ...

concept planned by the

McDonnell Douglas McDonnell Douglas was a major American aerospace manufacturing corporation and defense contractor, formed by the merger of McDonnell Aircraft and the Douglas Aircraft Company in 1967. Between then and its own merger with Boeing in 1997, it ...

company in the 1990s. It was first conceived as a

trijet A trijet is a jet aircraft powered by three jet engines. In general, passenger airline trijets are considered to be second-generation jet airliners, due to their innovative engine locations, in addition to the advancement of turbofan technol ...

larger than the

MD-11 The McDonnell Douglas MD-11 is an American tri-jet wide-body airliner manufactured by American McDonnell Douglas (MDC) and later by Boeing. Following DC-10 development studies, the MD-11 program was launched on December 30, 1986. Assembly of t ...

, then stretched to a

quadjet A four-engined jet, sometimes called a quadjet, is a jet aircraft powered by four engines. The presence of four engines offers increased power, allowing such aircraft to be used as airliners, freighters, and military aircraft. Many of the firs ...

airliner. It was to be similar in size to the

Boeing 747 The Boeing 747 is a large, long-range wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2022. After introducing the 707 in October 1958, Pan Am wanted a jet times its size, ...

, but with greater passenger capacity through two full-length passenger decks. However, the MD-12 received no orders and was canceled. McDonnell Douglas then studied larger MD-11 derivatives named ''MD-XX'' without proceeding.

Design and development

Background

McDonnell Douglas studied improved, stretched versions of the

trijet, named MD-12X"MDC brochures for undeveloped versions of the MD-11 and MD-12."
md-eleven.net. Retrieved: April 14, 2008. with a possible lower-front passenger deck with panoramic windows. The MDC board of directors agreed in October 1991 to offer the MD-12X design to airlines. The MD-12X had a length of and wingspan of . In November 1991, McDonnell Douglas and Taiwan Aerospace Corporation signed a Memorandum of Understanding to form a company to produce the new design. The new company would have McDonnell Douglas as the majority shareholder (51%) with Taiwan Aerospace (40%) and other Asian companies (9%) having the remaining shares.

MD-12

In late 1991, McDonnell Douglas made a move to separate its civil and military divisions in a bid to raise the estimated $4 billion development costs needed to develop the MD-12X trijet. Separating the costly military C-17 airlifter development, which had been a drain on the company's resources, from the profit-making production of the MD-80 and MD-11 airliners would make it easier to attract foreign investors for the MD-12X. The design grew into the much larger MD-12 with four engines and two passenger decks extending the length of the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

. The length of the main MD-12 variants was with a wingspan of . The fuselage was wide by high. McDonnell Douglas unveiled its MD-12 design in April 1992. The design was similar in concept to the Airbus A3XX and

Boeing New Large Airplane The Boeing NLA, or New Large Airplane, was a 1990s concept for an all-new quadjet airliner in the 500+ seat market. Somewhat larger than the 747, this aircraft was similar in concept to the McDonnell Douglas MD-12 and later Airbus A380. In 1993, B ...

, and it would have been larger than the

with which it would have directly competed.

Douglas Aircraft The Douglas Aircraft Company was an American aerospace manufacturer based in Southern California. It was founded in 1921 by Donald Wills Douglas Sr. and later merged with McDonnell Aircraft in 1967 to form McDonnell Douglas; it then operated as ...

had also studied a smaller double decker design in the 1960s. The first flight of the MD-12 was to take place in late 1995, with delivery in 1997. Despite aggressive marketing and initial excitement, especially in the aviation press, no orders were placed for the aircraft. MDC lacked the resources after Taiwan Aerospace left the project. Some skeptics believed that MDC launched the project to lure Boeing into paying a higher price for the company. A new double deck widebody has proved to be extremely expensive and complex to develop, even for the remaining aerospace giants Boeing and Airbus, although the massive

Airbus A380 The Airbus A380 is a large wide-body airliner that was developed and produced by Airbus. It is the world's largest passenger airliner and only full-length double-deck jet airliner. Airbus studies started in 1988, and the project was annou ...

, a similar concept to the MD-12, was later brought to fruition, but was not a financial success.

MD-XX

With the MD-12 program over, McDonnell Douglas focused on 300 to 400–seat MD-11 derivatives. At the 1996 Farnborough International Air Show, the company presented plans for a new trijet with high-seating and long-range named "MD-XX"."McDonnell Douglas Unveils New MD-XX Trijet Design."
McDonnell Douglas, September 4, 1996. The MD-XX was offered in two variants; MD-XX Stretch with a longer fuselage and MD-XX LR for longer range. Both MD-XX variant designs had wingspan, the same as MD-12. The MD-XX Stretch was lengthened over the MD-11 and had seating for 375 in a typical 3-class arrangement and 515 in all-economy seating. Its range was to be . The MD-XX LR was the same length as the MD-11, had seating for 309 in a typical 3-class arrangement and featured a range of . However, the MDC board of directors decided to end the MD-XX program in October 1996, stating the financial investment for the program was too large for the company.

Variants

The MD-12 was offered in a few proposed variants as listed below. *MD-12 HC (High Capacity) *MD-12 LR (Long Range) *MD-12 ST (Stretch) *MD-12 Twin (two-engine version)

Specifications (MD-12 High Capacity design)

References

;Notes

External links

Undeveloped MD-11/MD-12 models page on MD-Eleven.net

{{Douglas airliners Abandoned civil aircraft projects of the United States Quadjets MD-012 Low-wing aircraft McDonnell Douglas MD-11