McDonnell Douglas MD-12

MD-12
CG render of the proposed MD-12, a full double-decker configuration concept
Role	Double-decker wide-body aircraft
National origin	United States
Manufacturer	McDonnell Douglas
Status	Design study

The McDonnell Douglas MD-12 was an aircraft design study undertaken by the McDonnell Douglas company in the 1990s for a "superjumbo" aircraft. Had it been built, it would have been similar in size to the Boeing 747, but with a higher passenger capacity.

Design and development

McDonnell Douglas studied improved, stretched versions of the trijet MD-11, named MD-12X^[1] with a possible lower-front passenger deck with panoramic windows.^[2][3] The MDC board of directors agreed in October 1991 to offer the MD-12X design to airlines. MD-12X had a length of 237 ft 11 in (72 m) and wingspan of 212.5 ft (64.39 m). 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.^[3]

The design then grew into the much larger MD-12 with four engines and two passenger decks extending the length of the fuselage. The length for the main MD-12 variants was 208 ft (63 m) and had a wingspan of 213 ft (64.54 m). The fuselage was 24 ft 3 in (7.4 m) high by 27 ft 11 in (8.5 m). McDonnell Douglas unveiled its MD-12 design in April 1992. First flight on the MD-12 was to be in late 1995, with delivery in 1997.^[3] This was similar in concept to the Airbus A3XX and Boeing NLA, and would have been larger than the Boeing 747 with which it would have directly competed. Douglas Aircraft had also studied double-decker design in the 1960s.^[4]

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.^[3] A new double deck widebody has proved to be extremely expensive and complex to develop, even for the remaining aerospace giants Boeing and Airbus. A similar concept to the MD-12, the massive Airbus A380 has been successfully brought to fruition.^[5][6]

MD-XX

With the MD-12 program over, McDonnell Douglas focused on 300-400 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".^[7] 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 213 ft (64.5 m) wingspan, the same as MD-12. The MD-XX Stretch was lengthened 32 ft (9.7 m) 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 7,020 nmi (13,000 km). 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 8,320 nmi (15,400 km). However, the MDC board of directors decided to end the MD-XX program in October 1996. The investment in the program was too large for the company.^[3]

Variants

The MD-12 was offered in a few proposed variants.^[3]

• 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)

Data from McDonnell Douglas promotional materials^[1]

General characteristics

• Crew: 2 (pilot and co-pilot)
• Capacity: 430 Passengers in 3-class arrangement, up to 511 passengers in high-capacity layout
• Length: 208 ft 0 in (63.40 m)
• Wingspan: 213 ft 0 in (64.92 m)
• Height: 74 ft 0 in (22.55 m)
• Wing area: 5,846 ft² (543.1 m²)
• Empty weight: 402,700 lb (187,650 kg)
• Max takeoff weight: 949,000 lb (430,500 kg)
• Powerplant: 4× General Electric CF6-80C2 high-bypass turbofans, 61,500 lbf (274 kN) each

Performance

• Maximum speed: Mach 0.85 (565 mph, 1,050 km/h)
• Range: 7,170 nmi (9,200 mi, 14,825 km)
• Wing loading: 162.3 lb/ft² (792.7 kg/m²)

See also

Related development

• McDonnell Douglas MD-11
  

Comparable aircraft

• Airbus A380
• Boeing NLA
• Boeing 747X
  

References

• Steffen, Arthur. McDonnell Douglas MD-11: A Long Beach Swansong. Midland, January 2002. ISBN 1857801172.

External links

Wikimedia Commons has media related to: McDonnell Douglas MD-12

• Undeveloped MD-11/MD-12 models page at MD-Eleven.net
• "McDonnell May Build A Larger Jet", New York Times, March 16, 1992.
• "Orders for Douglas' commercial jets sag", Los Angeles Business Journal, June 22, 1992.
• "Will Airbus Buy Douglas?", Flug Revue Online, December 1996.
• Douglas Drops Jet Program, Associated Press, 1996.