The ECU, integrated into the Dome Assy, must process the signals for servo-valve controlling the jacks nozzles, from orders from Automatic Pilot (AP) and from the information of position provided by the feedback potentiometers located on the pistons of jacks.
The placement is being implemented through four hydraulic jacks (two per nozzle, located at 90° each other) each controlled by a servo-valve. The positions taken by the jacks are recognized by the four potentiometers connected to the same jacks. The ECU, according to the orders received by the PA and the positions detected by potentiometers, establish the values of the current command for the servo-valves.