Originally Posted by
The Ancient Geek
It depends on the RPM that you have set on the prop lever.
If the engine is not producing enough horses to turn the prop at that speed the prop will reduce pitch to keep up.
In practice you always set the prop to max RPM on approach.
Ok, so does the bottom of the green arc on the MAP gauge signify (normally about 15 inches) that below this the prop is going to fine pitch automarpticakky if it ain't there already ?