I have a 912S with the wide blade Warp Drive prop. Based on comments in the
forum, I haven't tried a full power stationary run for fear of a prop strike.
Instead, the prop was set to 18.5 degrees initially and then increased in
stages until it is now set at 20.5 degrees.
This setting yields a reasonable climb and much better speed than earlier
settings.
At 4500 ft and 5500rpm the manifold pressure is 23 inHg, where IAS is 125kt,
TAS = 134. When the throttle is advanced to full, the MP rises to 26 and a
climb must be started to constrain RPM to 5500.
Is there a way to estimate engine power output based on RPM and MP from the
information in the Rotax manual? The 23 inHg number is lower than the values
shown in the manual which seem to be for VP props.
Is there a way to objectively judge the climb/speed tradeoff imposed by a
fixed pitch prop? Does prop setting affect the speed at which max ROC occurs?
What is typical RPM at 75kt in a full power climb?
John N44EU
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