Regional airliner were replaced by progressively longer-range designs. In the immediate post-war era these were typically Douglas DC-3s, although even the De Havilland Dragon Rapide biplane airliner remained in service for some time. This "hand-me-down" process of supplying aircraft continued with designs like the Convair 440, Douglas DC-6 and Vickers Viscount also serving in this role while the first jets were introduced. By the mid-1950s, demand for even more economical designs led to the production of the first custom feederliners. These were almost always turboprops, which had fuel economy on par with piston engine designs, but had far lower maintenance costs. Often
Nihon Aircraft Manufacturing Corporation different manufacturing companies and university professors, NAMC was founded in April 1957 by executives from Mitsubishi Heavy Industries, Fuji Heavy Industries, Shinmeiwa Manufacturing, Sumitomo, Japan Aircraft, Showa Aircraft, and Kawasaki Heavy Industries with the goal of designing and manufacturing a Japanese civilian turboprop airliner to replace the successful but aging Douglas DC-3. The resulting aircraft, the YS-11, became the only successful civilian airliner to come out of Japan in the 20th century and the only airliner designed and produced in Japan for over 50 years until the Mitsubishi Regional Jet made its maiden flight in 2015. By the late 1970s,