109 prop pitch (rpm) and the supercharger

[ATAG_Snapper]

Not modelled in Cliffs of Dover, but apparently the BoB Spit pilots discovered that with the 2-speed props they could manipulate the pitch control lever in the center of its travel and get a variable pitch response, which they used to great effect in optimizing performance.

This is not to be confused with a Constant Speed Propellor, which to a great extent could maintain a desired speed (rpm) by automatically adjusting the pitch in response to throttle (boost) settings or aircraft maneuvring. The 2-speed prop, even at intermediate pilot-manipulated settings, would change rpms at different throttle settings and different changes in plane maneuvring, and thus bear careful watching (and listening).

This little trick pre-empted the need or desire to abruptly shift from Full Coarse to Full Fine (and vice versa).