Hydraulic Surface Control Booster System
AFCS ENGAGEMENT VALVE. -- T h e
The hydraulic surface control booster system
disengage or relaxed position. No voltage is at the
coil, and 3,000 PSI hydraulic pressure pushes the
control components. The automatic flight control
solenoid piston to the left. This action allow the
system (AFCS) engagement valve is a selector
hydraulic fluid to flow to the right side of
valve. It either applies pressure to or removes
the spring-loaded piston. With the same pressure
pressure from the AFCS portion of the booster.
on both sides, the spring-loaded piston moves
The hydraulic transfer valve controls the direction
to the left, preventing any further flow in the
and amount of fluid to the booster.
Figure 4-13.-Hydraurlic surface control booster with no mechanical input and AFCS disengaged.