Propeller Optimum Angle of Attack?

[Zosma Procyon]

What is the optimum angle of attack for the "Propeller Blade Type S"? I'm experimenting with a second flying science base for possible deployment to Eve.

[s_gamer101]

I usually just activate „Deploy“ on the propeller blades.

[OHara]

All the blades from the Breaking Ground mod have peak lift at 9° angle of attack. 
(This is a smaller angle than the 30° that give maximum lift for other KSP wings and control surfaces.)

I have not found the angle for best lift-to-drag ratio, but would guess 5°.   Someone else might have that answer.  Or you might decode the sections in the file 'Physics.cfg' that list points defining the lift and drag curves.

These are angles relative to the airflow across the blade.  As the craft's airspeed changes, changing the angle of the blade on the rotor (like a variable-pitch prop) is important to get the most out of these blades -- especially the BG blades with their narrow optimal angle.