"可调螺距螺旋桨" can be translated into English as "controllable pitch propeller (CPP)" or "adjustable pitch propeller".
"Controllable pitch propeller (CPP)" is a more technical and commonly used term in the marine engineering field, emphasizing the controllability of the propeller's pitch.
"Adjustable pitch propeller" is also a correct and straightforward translation, highlighting the adjustable feature of the propeller's pitch.
Both expressions are acceptable, and the choice may depend on the specific context or preference.