In Controllable or Variable Pitch Propellers (CPP), the propeller blades are attached to the boss and their pitch can be altered via a hydraulic system. The blades are removable so if they incur damage, can be repaired without removal of the whole propellor.
For the advantages that a CPP system gives, the CPP propellor is also more complex. Instead of the Monoblock design of a Fixed propellor, the CPP has multiple moving parts in the propellor and shaft, and a hydraulic system with which to control the pitching.
ATZ can support you with inspections and repairs afloat, in dock or even with a dive team. Either way, ATZ can support all your class approved CPP propellor requirements.