"McDonnell Douglas MD-90"@en . . . . . . . . "The MD-80 series was derived from the DC-9 and it was introduced commercially in October 1980. The MD-80 series was followed in modified form by the MD-90 in 1989 and the MD-95/Boeing 717 in 1998."@en . . . . . . "The MD-80 series was derived from the DC-9 and it was introduced commercially in October 1980. The MD-80 series was followed in modified form by the MD-90 in 1989 and the MD-95/Boeing 717 in 1998."@en .