The Ivchenko AI-20 is a Soviet turboprop engine developed in the 1950s. It has been built in large numbers, serving as the powerplant for the Antonov An-12 transport and the Ilyushin Il-18 airliner.
The AI-20 was the first gas turbine engine developed by the design bureau led by Oleksandr Ivchenko based at Zaporozhye, Ukraine, which had previously concentrated on small piston engines such as the Ivchenko AI-14 and AI-26 radials. It was designed as a prospective powerplant for the new large Ilyushin Il-18 airliner and the Antonov An-10, to be powered by four turboprops, in competition with the Kuznetsov NK-4. Both engines were tried out on the pre-production batch of 20 Il-18s, but the Ivchenko engine was chosen for full production, possibly due to a crash caused by an in-flight failure of an NK-4 engine, and possibly due to the desire for the engines of the Ukrainian An-10 to also be built in Ukraine.
The AI-20 is a single shaft turboprop with a ten-stage axial compressor and a three stage power turbine, and is designed to run at a constant speed. The overhaul life of the engine was initially reported as 600–750 hours in 1964, but was later improved to 6,000–7,000 hours, with a service life of 20,000 hours.