A) HYDRAULIC ROTARY UNION
With precision micro-machined seal surfaces. Allows for oil flow through the centre of the reduction drive shaft.
B) MANUAL HYDRAULIC PUMP
To control the propeller pitch via manual thumb-screw.
C) ELECTRO-HYDRAULIC PUMP
To control the propeller pitch via manual electric switch. Can be connected to the electronic governor to transform from basic in-flight variable-pitch control to a propeller with constant-speed control.