Study-Powerplant and Propellors

  1. Once and engine has been auto-feathered, what protection do you have against the other engine feathering?
    The interlock circuitry
  2. For the prop sychrophase system, which is the master and slave?
    Left is Master, right is Slaved to it's speed.
  3. At what prop RPM will the over-speed governor start to control the prop



  4. What is the function of the Beta backup system?
    To prevent the prop entering ground beta range unintentionally due to a PCU malfunction
  5. What is the propeller inhibited range?
    500-780 RPM
  6. What triggers and autofeather?
    When an SCU detect torque is less than 22% on one engine whilst it's about 50% on the other engine
  7. What is the max rated shaft horsepower for takeoff with uptrim?
    2150 (2000 PW120A)
  8. How much oil does the engine oil system hold?
    6 US Gals
  9. What indication would you have if an ECU has failed or has been selected to manual?
    MANUAL indication on ECU mode switchlight and power loss
  10. What can occur if a Condition Lever is selected too far past START/FEATHER during engine start?
    The associated ECU can be deactivated
  11. What is the model number of the powerplant?
    PW121 (PW120A)
  12. What is the maximum altitude for an airstart?
  13. If electrical power is removed from an engine instrument, what will the gauge indicate
    Pointer to zero, LCD blank
  14. What happens to the propeller if the associated engine loses oil pressure
    Pitch Lock at the point when the pressure is lost. Pitch and RPM stay within 2%
  15. If an ECU or Torque Motor were to fail during takeoff, why would power rollback be limited to 10 to 20%?
    When the ECU fails the Enrichment Solenoid Valve would be de-energized open, manually enriching the fuel flow
  16. When landing with an inoperative ECU, what precautions should be observed
    Do not retard associated power lever below DISC, 2- Feather the associated prop after clearing the runway
  17. What happens when disarming the autofeather system after an engine failure on takeoff?
    Uptrim is disabled and the good engine rolls back 10%
  18. What cockpit caution or advisory lights would be illuminated if an ECU fails or is not operating
    ENG MAN caution light, and Master Caution light flashing
  19. Why is the ECU selector placed at TOP for takeoff
    • Provides fail-fix mode in the event of a minor ECU failure on takeoff (= no initial power rollback), 2-insures that
    • only a small amount of power rollback (10 to 20%) will occur if the torque motor fails during takeoff.
  20. At what percent of Nh does the start sequence terminate?
  21. If a Torque Motor failure occurs during takeoff, what cockpit indications would be evident?
    10% to 20% drop in torque. No caution lights
  22. What is the rated max S.H.P. for takeoff without uptrim?
    1950 (PW120 – 1800)
  23. If a Torque Motor were to fail during cruise, what indications would be evident?
    50% or greater rollback in torque (select ECU off to de-energize Enrichment Solenoid Valve open
  24. If a major ECU failure occurs during takeoff, what cockpit indications would be evident?
    10% to 20% drop in torque and associated ENG MANUAL caution light illuminated with Master Caution flashing
  25. What two components are used to schedule fuel?
    HMU & ECU
Card Set
Study-Powerplant and Propellors
Study-Powerplant and Propellors