The DC-9 (10-series) first entered service with Delta Airlines in 1965. The lengthened version, identified as the DC-9 series 20, began development in 1965 and the even longer series 30 first entered service in 1967. The DC-9 30 series also included extended wings and uprated engines with more thrust.

McDonnell Douglas designs and produces a variety of aerospace and defense products. It is one of the world's largest space and defense contractors and the third largest manufacturer of commercial aircraft. The corporation was created in 1967 with the merger of the McDonnell Company of St. Louis and the Douglas Aircraft Company of Southern California. Located in Long Beach, the Douglas Aircraft Company is the commercial aircraft componant of the McDonnell Douglas Corporation. It was founded in 1920 by Donald W. Douglas, and has since delivered more than 45,000 aircraft, including the long line of Douglas Commercial (DC) and McDonnell Douglas (MD) models. The Douglas Aircraft Company employs approximately 11,000 people.