McDonnell Douglas MD-80

Development

The DC-9 series, the first generation of the DC-9 family, entered service in late 1965 and became a commercial success with 976 units built when production ended in 1982. The all-new designed aircraft family includes five members or variants (DC-9-10 / DC-9 Series 10, Series 20, Series 30, Series 40, and Series 50) with ten sub-variants or versions (Series 11, Series 12, Series 14, Series 15, Series 21, Series 31, Series 32, Series 33, Series 34, Series 41, and Series 51) and features two rear fuselage-mounted turbofan engines, a T-tail configuration, a narrow-body fuselage with five-abreast seating for 80 to 135 passengers. The success prompted the manufacturer to further develop the aircraft family with the last member, Series 50, as the reference aircraft.

Feasibility study

In the 1970s, McDonnell Douglas began development of the first derivative or second generation of the DC-9 family, a lengthened version of the Series 50, with a higher maximum take-off weight (MTOW), larger wing, new main landing gear, and higher fuel capacity. Availability of newer versions of the Pratt & Whitney JT8D turbofan engine with higher bypass ratios and thrust ratings drove early studies including designs known as Series 55, Series 50 (refanned Super Stretch), and Series 60. In August 1977, the design effort focused on the Series 55.

Program launch

With entry into service projected in 1980, the improved aircraft design was initially designated as the Series 80, which would be the sixth variant of the first generation. In October 1977 Swissair became the launch customer for the Series 80 with an order for 15 plus an option for 5. The launch of the next aircraft models followed in October 1977 for the Series 81 (MD-81), on April 16, 1979, for the Series 82 (MD-82), on January 31, 1983, for the Series 83 ( MD-83). In January 1985 came the introduction of the Series 87 (MD-87), and on January 23, 1986, the Series 88 (MD-88).

Certification

Type designation

Similar to the first generation of the DC-9 family, the second generation uses second-digit notation, with zero for variant names (Series 80) and non-zero for subvariant or version names (Series 81 through Series 88). Because there was only one variant within the second generation, the Series 80 became the family name and the Series 81 through Series 88 became variant or version names. The first Series 80, DC-9 line number 909, made its first flight on October 18, 1979, as the Super 80, which then became the preferred designation for the newly developed aircraft family. Although two aircraft were substantially damaged in accidents, flight testing was completed on August 25, 1980, when the first variant and production model, the JT8D-209-powered Series 81, was certified under an amendment to the FAA type certificate for the DC-9. The flight-testing leading up to certification had involved three aircraft accumulating a total of 1,085 flying hours on 795 flights. After production of the first generation ended in late 1982, a new designation with McDonnell Douglas initials, MD-80, was proposed as the type designation for the second generation and in July 1983, McDonnell Douglas decided that the Super 80 would be officially designated the MD-80. However, the type designation according to the type certificate (TC) is still the original (DC-9 prefix) to save on certification costs, but could also be provided with the new (MD prefix) written in parentheses, e.g. DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83) and DC-9-87 (MD-87). Only the last variant, the MD-88, was officially certified under the MD designation.

Type certification (TC)

Following the MD-81's first flight on October 18, 1979, the MD-82 and MD-83 made their maiden flights on January 8, 1981, and December 17, 1984, respectively. They were then certified by the FAA on August 25, 1980, July 29, 1981, and October 17, 1985, respectively. The first airliner, an MD-81, was delivered to launch operator Swissair on September 13, 1980. Instead of merely using the MD- prefix as a marketing symbol, an application was made to again amend the type certificate to include the MD-81, MD-82, and MD-83. This change was dated March 10, 1986, and the type certificate declared that although the MD designator could be used in parentheses, it must be accompanied by the official designation, for example: DC-9-81 (MD-81). All Long Beach aircraft in the MD-80 series thereafter had MD-81, MD-82, or MD-83 stamped on the aircraft nameplate.

The MD-87 and MD-88 made their first flight on December 4, 1986, and August 15, 1987, respectively. Although not certified until October 21, 1987, McDonnell Douglas had already applied for models DC-9-87 and DC-9-87F on February 14, 1985. The third derivative was similarly officially designated DC-9-87 (MD-87), although no nameplates were stamped DC-9-87. For the MD-88, an application for a type certificate model amendment was made after the earlier changes, so there was not a DC-9-88, which was certified on December 8, 1987.