Refer to figure.
A single engine airplane fitted with a constant speed propeller may not have a “feathering” capability, as such. However, following engine failure, drag can be reduced to a minimum by “pulling” the RPM (prop) control to the fully coarse position.
In a steady glide with no shaft power from the engine (throttle closed), if the propeller pitch is decreased by pushing forward the prop’ lever, the aircraft Lift/Drag ratio will decrease. This will increase the rate of descent.
The opposite will be true if the propeller pitch is increased.
Your Notes (not visible to others)