The McDonnell Douglas DC-9 (initially known as the Douglas DC-9) is a twin - engine , single- aisle jet airliner . It first flew and entered airline service in 1965 . The DC-9 was designed for frequent, short flights. The final DC-9 was delivered in October 1982.
DC-9-based airliners including the MD-80, MD-90 and Boeing 717 (MD-95) later followed in production. With the final deliveries of the 717 in 2006, production of the DC-9/MD-80/90/717 aircraft family ceased after 41 years and 2441 units built.
During the 1950s Douglas Aircraft studied a short- to medium-range airliner to complement their higher capacity, long range DC-8. (DC stands for Douglas Commercial.) A medium-range four - engine Model 2067 was studied but it did not receive enough interest from airlines and it was abandoned. In 1960, Douglas signed a two-year contract with Sud Aviation for technical cooperation. Douglas would market and support the Sud Aviation Caravelle and produce a licensed version if airlines ordered large numbers.