Unknown

The 'Unknown' is a versatile light transport aircraft produced by the 558 Aircraft Repair Plant in the early 1990s. Conceived as a stop‑gap solution after the collapse of the Soviet aviation industry, the program repurposed surplus airframes and components to create a reliable, low‑cost platform for regional operators. First flight took place on 12 May 1993, and a limited series of 27 airframes was delivered to municipal air services, oil‑field logistics firms, and humanitarian agencies throughout the former USSR.

Key features include a high‑wing, all‑metal construction with a rugged fixed tricycle landing gear, allowing operation from unpaved strips. Powered by two Ivchenko‑AI‑24 turboprop engines rated at 1,800 shp each, the aircraft delivers a maximum cruise speed of 380 km/h and a range of 2,400 km with a 1,200‑kg payload. The cockpit incorporates a dual‑control layout with basic avionics that can be upgraded to modern GPS‑based navigation. Its simple maintenance philosophy and interchangeable parts made it especially attractive to remote operators.

Although never exported in large numbers, the Unknown demonstrated how a modest repair facility could produce a functional transport aircraft under constrained resources, influencing later Russian utility designs and underscoring the strategic value of domestic repair capabilities.