OK all you engineer types...Can someone explain how we will know when our
variable pitch prop is set correctly for a given cruise setting?  On
certified aircraft, you adjust rpm and manifold pressure based on the POH
correct?  So how will this take place with a rotary?

Trial and error with good instrumentation like fuel flow and GPS. PL

I understand that minimum pitch would be used for takeoff and climb-out, and
then once at altitude and set for cruise you increase the pitch of the prop.
  This leads to the prop getting a better "bite" on the air and increases
its efficientcy/effectivness.  As this happens, rpm decreases correct?  So
how will one know when to stop increasing the pitch?  "Can you over-tax the
engine" with too much pitch?

Probably not with a rotary but that is certainly a consideration with
a piston engine. But by all means use a knock sensor to be sure. PL

Please respond to this in the following way so that I can follow you:

1.  Correct any of the assumptions/statements that I have made above due to
a lack of mechanical knowledge.

2.  Explain how we will figure out the proper pitch short of just trial and
error.

No way I know of without trial and error. PL

Thanks for your help and patience with this non-engineer.

Take care, Marc M

Paul Lamar
 
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