Vacuum sys. driven instruments on helicopters?
I am browsing thru some training material about helicopter systems - and I came across one that says there is no helicopter with vacuum system installed (used to drive gyro instruments)
I believe there is none installed on a turbine helicopter, but piston engine ones?
Anyone who can help me out with an example of standard fit vacuum system on a (piston engine) helicopter, that is currently in use in FAA/EASA world?
THX
hoistop