Card Set Information

2013-11-14 09:08:28
Hydraulics S76

S76 C+ hydraulic system
Show Answers:

  1. Composed of...
    • Four independent systems:
    • 1. First-stage hydraulic system (flight controls with T/R shut off)
    • 2. Second-stage hydraulic system (flight controls and utility hyd sys)
    • 3. Wheel brake system (and parking brake)
    • 4. Rotor brake system
  2. Utility Hyd Sys
    • On 2nd stage hydraulic module:
    • 1. Landing gear components (extension and retraction)
    • 2. Priority valve - senses loss in system pressure >2,250PSI, and closes to give priority to M/R and T/R servos
    • 3. Pedal damper/yaw trim actuator
  3. Servo Switches
    • On each Pilot and CPilot coll
    • If Pilot switched a servo off, only that switch can be used to switch on again
    • Switches connected to Ess Bus, 2 CBs
    • Fail-On system
  4. Pressure Indications (stages 1 and 2)
    • Normal is 3,000PSI (available by  10%NR)
    • SERVO SYS caution light if drops below 1,600PSI
    • Gage on Engine page (IIDS) is slider only, no numbers
    • Little Red Buttons on both pressure and return filters (4 total)
  5. Filters (stages 1 and 2)
    • Each stage: output line filter (nonbypass), and return bypass filter
    • Line filter LRB pops at 7010psi differential
    • Return filter LRB pops at 10010psi differential
  6. T/R Servo Shutoff Valve
    • On the 1st stage hydraulic pressure line only
    • If fluid level switch activates, the solenoid shutoff valve blocks flow to #1 T/R servo (#1 SERVO SYSTEM caution on)
    • Even if 2nd stage hyd loses pressure too, 1st stage will supply pressure to M/R servos
    • (#1 SVO SHUTOFF CB on Ess Bus)