Prop Lever shows no effect?

[Luigi Gorgonzola]

As I haven't found something similar already reported:

 

As far as I understand the manual, the Prop lever of the quadrant does essentially the same as the switch at the prop switch box - decrease and increase prop rpm. However, I cannot see this effect. Using the switch produces the expected result, but using the lever doesn't change anything, disregarding the switch position (auto or manual).

I may understand the manual wrong, though.

[saburo_cz]

The switch at the prop switch box controls directly the propeller motor which moves with blades, to set propeller pitch (and controls RPM when the engine is running).

 

But the propeller lever on the throttle quadrant controls the propeller governor (not directly the propeller motor) and the propeller governor controls the propeller motor according to lever position and the engine torque (manifold pressure - the engine power).

 

When the engine is not running, there is no torque (power from engine), the propeller governor thries to set as low propeller pitch as possible, does no matter where the propeller lever is.

[Luigi Gorgonzola]

Kthx, I did the run-up when I encountered the symptom . Tried in flight and all fine. Thanks!