Glossary
What is a constant speed propeller?
A propeller whose blade angle changes automatically to hold whatever engine speed the pilot selects. It adds a second lever alongside the throttle, the propeller control, and it lets the engine make efficient power across a much wider band of airspeeds.
Also called Controllable pitch propeller
That is the whole entry for now. The longer version, with the mechanics and worked examples, is still to be written. See autorotation for how those read once they exist.