Isotov as it is known in the West, is actually Izotov. Sergei Pietrovich Izotov, born in 1918.

-He is the designer of important Russian turboshaft and turboprop engines.

-His office (OKB) was responsible for the design of the TVD-850, TV2-117, Tb2-117 and GTD-350 engines used in several Antonov aircraft (14M, etc) and helicopters such as the Mi-8, - 17, etc.

“GTD-350”

-The low-power GTD-350 that delivers 395 SHP has a very suspicious similarity with the Allison 250 (although it can not be sure that it was the other way around). It began to be used in 1957 on the Mi-2, until today.

“TV2-117”

-The TV2-117 are free-turbine turboshafts. They have a 10-stage compressor, an annular combustion chamber, a 2-stage HP turbine -for gas generator-, and a 2-stage LP power turbine. It delivers 1,500/2,000 SHP.

-The TV3-117, with 2,300 SHP of maximum power, were used on the Kamov helicopters.

-The medium TVD-850 with 810 SHP did not have the expected commercial output.

-Isotov died in 1983 and his organization passed to the Klimov group. Some Isotov engines are manufactured in Poland by WSK-PZL in Rzeszhow.

From Appendix 6: The TV3-117 engine is not shown in the main text so below we offer a recently received picture.

“Isotov TV3-117”