Douglas DC-9-30 Swissair

McDonnell Douglas DC-9 was created to improve the company's commercial offer and replace it with the DC-8 four-engine aircraft. When designing the DC-9 aircraft, the focus was primarily on the high ergonomics of the machine and the lowest possible operating costs. Several development versions were created in the course of serial production. The first mass-produced was the DC-9-15. Shortly thereafter, a version of the DC-9-20 with improved aerodynamics and wings was created. In 1975, DC-9-50 planes appeared with a passenger cabin that could take up to 139 passengers. It was by far the largest of the mass-produced versions of the DC-9.