The NAMC YS-11 is a turboprop airliner designed and built by the Nihon Aircraft Manufacturing Corporation (NAMC), a Japanese consortium. It was the only post-war airliner to be wholly designed and manufactured in Japan until the development of the Mitsubishi SpaceJet during the 2010s, roughly 50 years later.

Development of the YS-11 can be largely attributed to Japan’s Ministry of International Trade and Industry (MITI), which had encouraged Japanese aircraft companies to collaborate on the development of a short-haul airliner as early as 1954. In 1959, NAMC was formed to design and produce an aircraft to satisfy MITI’s requirements, dubbed the YS-11. On 30 August 1962, the first prototype performed its maiden flight. Deliveries commenced on 30 March 1965 and commercial operations began the following month. The majority of orders for the type were issued from various Japanese airliners. While sales to such customers were swift in the YS-11’s initial years of availability, this limited market soon became saturated, leading to a slump in demand.

Following efforts to acquire more sales from international customers, including the development of the improved YS-11A variant, production of the type ceased during 1974. Ultimately, while the YS-11 had demonstrated Japan’s ability to produce an airliner, NAMC had accumulated considerable debts and the type is largely considered to be a commercial failure. Large numbers of the type continued to be in service until 2006, at which point tighter Japanese aircraft regulations imposed by the Ministry of Land, Infrastructure, Transport and Tourism necessitated either the withdrawal or refitting of all YS-11s. By 2018, only a single example reportedly remained in commercial service.