Card Set Information

2011-12-11 17:25:37
Turbine Air Fuel Systems

Turbine Air/Fuel Systems
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  1. What are 3 primary functions of the Fuel control system?
    • Meter fuel
    • Provide overspeed protection
    • Provide fuel cutoff
  2. In a governor flyweight assembly, what does on speed, over speed and under speed meas?
    • on speed-fly weights=speeder spring tension
    • under speed-speeder sring>flyweights
    • overs speed-speeder spring<flyweights
  3. What is Py
    governor air
  4. The difference in fuel pressure felt across metering valve is compensated by ?
    Delta P valve
  5. What's not a required input for the FCU?
    Collective Position
  6. What are 3 inputs for the N2 governor?
    • collective
    • N2 speed
    • Pc
  7. What are the 4 lines that attach to the N2 governor?
    • Overspeed
    • Pr
    • Pg
    • Pc
  8. What provides the fuel scheduling from start up to ground idle?
    acceleration bellows
  9. What are 5 lines that would normally be found on the fuel pump?
    • Fuel input
    • fuel output
    • fuel bypass
    • filter in
    • filter out
  10. What are 2 types of fuel nozzles?
    Simplex and Duplex
  11. In a duplex nozzle, when does fuel come through the primary holes? secondary holes?
    • pri- low speed
    • sec-increase in pressure pushes spring down to open at high speeds
  12. What is a common precaution when handling fuel nozzles?
    What is the most efficient spray pattern?
    • Don't touch the end of the nozzle, effects spray pattern
    • Finely Atomized Spray is most efficient
  13. What is incorperated into a simplex nozzle to slow the atomized fuel down so it will burn?
    Swirl Vanes
  14. What are some of the tasks that can be done with a FADEC system?
    • Fault detection
    • Auto Start
    • Auto relight
    • Auto Overspeed protection
    • Surge Protection
  15. What do the follow ancronyms mean?
    • Rotor speed
    • compressor speed
    • power turbine speed
    • comp discharge air
    • governor pressure
    • ambient air pressure
    • governored air pressure
  16. What does FADEC stand for?
    Full Authourity Digital Electronic Control
  17. What does TMOP and MGT stand for?
    • Measured gas temp
    • Torque metered pressure
  18. What is the function of the flw divider in the Pratt fuel system?
    Shuttles over to set primary or secondary fuel nozzle
  19. What are some adjustments that can be made on the FCU?
    • Acceleration adjustments
    • idle speed
    • max govering speed
    • part power trim stop
  20. In a FADEC system, what are the 3 faults called?
    • Fadec Degrade-may effect engine proformance,
    • Fadec Fault-may effect engine operating features such as engine limiting
    • Restart Fault-engine may not start in auto
  21. How are N1, N2 and Nr measured
    uses mono pole pickups to count the number of teeth over time
  22. How does the auto relight system know when to fire?
    • looks for N1, ITT and torque
    • Initiated if ECU detects flame out, annunciator light will stay illuminated during the duration
  23. What is setting the Ng idle speed?
    idle screw in speeder spring
  24. What is the relationship between Px and Py when the governor is onspeed?
  25. In a PT-6 engine what comps for altitude to give an absolute pressure reference?
    Acceleration Bellows
  26. What would happen if the acceleration bellows had a hole in it?
    engine would go to min fuel flow