YS-11M

The YS‑11M is a turboprop airliner developed in the early 1970s by Nihon Aircraft Manufacturing Corporation (NAMC), an effort that built on the successful twin‑engine YS‑11 transport introduced in 1965. While the original YS‑11 served regional airlines with piston‑driven engines, the YS‑11M variant replaced the radial engines with more powerful Allison 501‑D (or similar) turboprops, delivering higher cruise speeds, better fuel efficiency and improved climb performance. First flown in 1972, the aircraft entered limited service with Japanese civil operators and a few military customers, where it was used for short‑haul passenger routes, cargo missions and maritime patrol duties. The airframe retained the low‑wing, all‑metal construction and pressurised cabin of its predecessor, but incorporated reinforced wing spars, upgraded avionics, and a redesigned propeller system that reduced noise and vibration. Although production numbers remained modest—only 20 airframes were completed—the YS‑11M demonstrated Japan’s capability to integrate Western turboprop technology into a domestically designed platform. Its legacy lies in paving the way for later Japanese transport projects such as the Mitsubishi MRJ and strengthening the nation’s aerospace industry in the post‑war era. Today a few YS‑11M airframes are preserved in museums worldwide.