pressurized helicopters?
 

Any body knows of any chopper, civil or military, that can be pressurized??:

Comanche was pressurized, to allow full filtering of the contaminated outside air to pretect the crew. I believe that the Mil gunships are also protected that way.

I believe the 609 is pressurized, to allow high speed cruise at high altitude.

No pressurization is needed for passenger comfort in helos, since the rotor gives up the ghost long before the passenger's lungs.

The Mil 26 cockpit is also pressurised, and I believe the Russian gunships were as well.

All are limited to cockpit areas only. The low oxygen levels in the back helps keep the vodka swilling masses under control!