That is an auxiliary power unit (APU) for pneumatic main turbine starting.
Required for self-contained operations. At least some models of Mil are
equipped with Ivchenko AI-9V APU unit.

Use e.g. Vivisimo meta-search engine www.vivisimo.com and type "Mil Mi APU"
and you get more information about the subject.

JP


kirjoitti
glegroups.com...
Hi, many of the large Mil helis have what looks like a third turbine
above, and slightly behind the two main turbines. What is it? All of
the specs for these helis say they have two turbines. I can see blades
in some photos, so it's obviously something like a turbine.


Thanks, Justin.

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