AirspeedAdjust (to obtain most comfortable control movement level)
HYDRAULIC BOOST switchCheck ON
HYD BOOST circuit breakerOUT
If system is restored
Land as soon as possible
If system is not restored:
5.HYD BOOST circuit breaker IN
6.HYDRAULIC BOOST switchOFF
7. ©FORCE TRIM (FT)ON
8. ©AFCS STABON
9. ©AFCS ALTOFF
10. © Land as soon as practicable
Identify the function of the pressure switch.
Continuously monitors hydraulic system pressure “downstream” from the filter.
State how the hydraulic pressure light operates with the pressure switch.
Closes and completes the “HYDRAULIC PRESSURE” caution lithe circuit when the pressure falls bellow 300 psi. The switch opens, turning off the caution light when pressure rises above 400 psi.
Identify the functions of the solenoid.
Spring loaded to the OPEN/on position and allows the hydraulic servos to be bypassed by applying 28 vdc to the solenoid.
Describe the operation of the solenoid valve relative to the hydraulic switch.
ONNo power to solenoid, spring loaded OPEN position, direct hydraulic fluid to the servos
OFF28 vdc applied to solenoid which overcomes the spring pressure and moves the valve to the BYPASS position which directs hydraulic fluid to the reservoir instead of going to the servos.
State how the hydraulic switch circuit is protected.
5 amp circuit breaker (outboard of igniter CB). If hydraulic boost switch shorts out the hydraulic solenoid will go to the bypass position. To remove the 28 vdc from the solenoid pull the circuit breaker which will restore the hydraulic system.
Name in the three major servo valves and state their functions.
Sequence Valve: Traps fluid in servo in case system pressure is lost. This allows control movement and absorbs rotor system feedback. (Maintains irreversibility)
Pilot Valve: Heart of the servo, it takes control inputs (from pilot) and ports fluid to proper side of servo to allow for boosted control inputs. When the flight control is at the proper position, pilot valve centers and fluid flow stops in the servo. When system pressure is lost the sequence valve traps fluid in the servo and