The 2556 pneumatic control heads were designed for controllable pitch (CP) propeller and engine speed functions. It’s longer handle will actuate 2 pressure regulating valves. It is providing “0” pressure for “0” pitch and in case of failure, the CP actuator will return to “0” pitch position.
The 2556 is available with illuminated side scales. It has a maximum supply pressure of 150 PSI (10,3 bar) and 1/8″ NPT.
A repair kit 2556-RK is available.