Ivchenko AI-20

AI-20
Ivchenko AI-20M turboprop engine
Type	Turboprop
National origin	Soviet Union
Manufacturer	Ivchenko/ZMKB Progress
Major applications	Antonov An-10 Antonov An-12 Ilyushin Il-18

The Ivchenko AI-20 is a Soviet turboprop engine developed by the Ivchenko design bureau 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 Zaporizhia, USSR, 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 engines. Both engines were tested on the preproduction batch of 20 Il-18s, but the Ivchenko engine was chosen for full production, possibly due to a crash caused by an inflight 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 Il-18B was powered by four Ivchenko AI-20A Series 1 turboprops, each providing a takeoff power of 2,985 kW (4,000 shp) and sustained power of 2,090 kW (2,800 shp) at cruise altitude. Early Il-18A production had initially been fitted with Kuznetsov NK-4 engines, but they were soon exchanged for AI-20s. Later Il-18B production featured AI-20A Series 2 engines, with the same power ratings, but with technical improvements, thus older machines were updated with the Series 2 powerplants. The AI-20s drove four-bladed variable pitch reversible props with a diameter of 4.5 meters (14 feet 9 inches), featuring prominent propeller spinners, and hydraulic actuation for prop pitch. The engines were mounted above the wing and featured integrated fire extinguishers. The engines were started with electric motors, the power for the motors being provided by a ground cart.

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Wikipedia