Systems Ch. 10 Hydraulics

  1. The hydraulic system supplies pressure for the operation of what
    Flaps, Landing Gear, Brakes, and Nose Wheel Steering
  2. Are Hydraulic lines routed to their respective systems inside the aircraft
    No, they are routed externally in "hydraulic tunnels"
  3. What pressurizes the main hydraulic reservoir
    Emergency accumulator circuit
  4. What is the back up to the emergency accumulator for pressurizing the reservoir
    Spring loaded piston
  5. What would cause a HYDR CWP light to illuminate with all gauges normal
    High Temperature (above 116C) in main reservoir
  6. What supplies hydraulic fluid to the Hand Pump Reservoir
    Overflow fluid from the main reservoir
  7. What does the Hand Pump reservoir supply fluid to
    Hand Pump
  8. What does the main reservoir supply fluid to
    • Electric hydraulic pump
    • Overflows to the Hand Pump Reservoir 
  9. What is the normal source of pressure for the hydraulic system
    Electric pump
  10. What electrical bus supplies power to the electric pump in AUTO
    Left main bus
  11. What electrical bus supplies power to the electrical pump in OVRD
    Left essential bus
  12. Why is it important to verify the BUS TIE CONN light illuminates during left engine shutdown while taxiing
    Hydraulic pump is powered from the left main bus
  13. With a failure of the electric hydraulic pump can the main accumulator be pressurized
    Yes, with the hand pump
  14. What does the Main Accumulator supply pressure to
    • Nose wheel steering
    • Flap actuation
    • Gear retraction and extension
    • To pressurize the brake accumulators 
  15. At what pressure does the Pressure relief valve vent pressure
    3750 PSI
  16. Is there protection for an overpressure of the hydraulic system
    Yes the pressure relief valve
  17. Where does the Pressure relief valve return fluid to
    To the main reservoir
  18. Where does the Fluid from the hand pump get returned to after use
    Main reservoir
  19. What is the most likely problem if a HYDR CWP light is illuminated and hydraulic quantity, main accumulator, and inboard accumulator pressure all indicate low
    A leak in the inboard brake
  20. What is the normal operating pressure in AUTO mode
    2100 psi- 2900 psi
  21. What is the operating pressure when the pump is in OVRD
    3000 psi
  22. What causes the electric pump to automatically activate
    • Pressure in the main accumulator decreases below 2100 psi
    • Landing gear is extended or retracted 
  23. What can the Hand Pump pressurize
    All accumulators except the Emergency accumulator
  24. The selector valve facilitates pressure of what
    Main, Inboard brake, and Outboard brake accumulators
  25. Can the landing gear be hand pumped down with a total electrical failure
    No, the gear requires lef battery bus power to operate the selector valve
  26. Can the flaps be hand pumped with a total electical failure
    No, flap operation requires left battery bus to be powered
  27. With an outboard brake accumulator leak, can the main accumulator be pressurized by the Hand Pump
    No, the Main accumulator will equalize to the leaking brake accumulator
  28. Which accumulators have check valves
    Emergency, Inboard and Outboard brake accumulators
  29. What is the pressure of he nitrogen pre-charge in the accumulators
    1650 PSI
  30. What pressure is read on the gauges if hydraulic qty in the accumulator decreases to zero, leaving just the nitrogen pre-charge pressure
    • Zero psi on the flight deck gauges
    • Actual accumulators should read 1650 psi in the nose well 
  31. What is the purpose of the Nitrogen charged accumulators
    To absorb pump pulsations and surges caused by large fluid demands
  32. What pressure triggers a HYDR CWP light to illuminate
    Pressure less than 1850 psi, or High Temp
  33. Which accumulators will trigger the HYDR CWP light to illuminate with pressure below 1850 psi
    Main and Emergency accumulators
  34. What is the purpose of the Emergency accumulator
    • Emergency extension for up lock release
    • To pressurized the Main reservoir 
  35. What is the indication for a hydraulic filter that is clogged and bypassed
    Clog indicator button pops up on the filter housing
  36. What is being pressurized by the Hand Pump when the selector is in the FLAPS LDG GR position
    The Main Accumulator
  37. How many hydraulic accumulators are on the Saab 340
  38. Why do the brakes have 2 accumulators
    One for inboard and one for outboard brake systems. In case of a leak in one sysem, brakes are still available
  39. What does the Emergency landing gear extension use hydraulic pressure for
    To release the up locks and allow the gear to free fall
  40. Can the flaps be etended AND retracted with only the Hand Pump
    Yes, by pressurizing the main accumulator
  41. Where can the 1650 psi Nitrogen pressure be checked
    Nose wheel well, right side of the aircraft
  42. Where are the hydaulic filter bypass pins located
    Nose wheel well on the left side of the aircraft
  43. What does an illumiated HYDR CWP light indicate
    • Pressure in the main or emergency accumulators less than 1850 psi
    • High Temp in the main reservoir (116C)
  44. Does the HYDR CWP light illuminate for low quantity
  45. Does the HYDR CWP light illuminate for the high pressure
  46. Where is the Hand Pump handle stored
    Behind the First Officer seat on the bulkhead
  47. Is the electric hydraulic pump protected by a resettable circuit breaker
Card Set
Systems Ch. 10 Hydraulics