"JP" wrote in message
...
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"

The APU is behind the transmission.

Slatts