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  1. What is the purpose of the FADEC?
  The FADEC controls the engine fuel flow based on various inputs from the airplane, engine, and propeller control system. Fuel scheduling is the primary function of the FADEC. The FADEC also has the following additional functions: • Controls various engine bleed valves to prevent compressor surges and stalls • Prevents engine overspeed (@ 108% NH) • Controls the automatic engine start sequence and engine shutdown • Supplies voltage to the Propeller Electronic Control (PEC) • Detects and indicates power plant faults (CFM Vol. II Chapter 17)
17-2) What start protections do the FADEC provide?
The FADEC will automatically terminate the start if: • The engine does not light within 16 seconds after introduction of fuel flow • The ITT limit of 920°C is exceeded (20 second max limitation) • NH does not reach 64% within 70 seconds (hung, slow start) (CFM Vol. II Chapter 17)
17-3) What is the start sequencing provided by the FADEC?
At 8% NH, FADEC commands ignition on one igniter and controls fuel scheduling, if there is not light off within 8 seconds, FADEC commands both igniters. (CFM Vol. II Chapter 17)
17-4) What is the indication of a partial loss of function of the FADEC?
A #1or #2 ENG FADEC Caution light and possible engine surges or required staggering power levers. (CFM Vol. II Chapter 17)
17-5) What is the indication of a full failure of the FADEC?
The illumination of the #1 or #2 FADEC FAIL Warning light, and power on respective engine failed or at idle. (CFM Vol. II Chapter 17)
17-6) What are the indications of UPTRIM?
An UPTRIM message appearing on the ED, a change in the operating engines power rating from NTOP to MTOP on the ED, a change in the operating engines torque bug position from NTOP to MTOP (CFM Vol. II Chapter 17)
17-7) What are the MTOP limits?
• Max torque = 106% • Max ITT = 880°C • Max NL % RPM = 100 • Max NH % RPM = 100 • Max NP RPM = 1020 • Oil Pressure PSID = 61-72 • Oil Temp °C = 0-107 (CFM Vol. II Chapter 17)
17-8) How are the intake heaters activated?
They are heated automatically when the intake bypass doors are open and the SAT is 15°C or below and there is 115-volt AC power available. (CFM Vol. II Chapter 17)
17-9) At what propeller RPM does the FADEC provide under speed governing (ground)?
660 RPM (CFM Vol. II Chapter 17)
17-10) What is the first propeller over speed protection?
The hydraulic section of the propeller overspeed governor reduces the high pressure oil supply when propeller speed exceeds approx 1071 RPM (CFM Vol. II Chapter 17)
17-12) When does the FADEC over speed protection occur?
FADEC commands the fuel-metering unit FMU to reduce the amount of fuel being supplied to the engine when a propeller overspeed of approx 1173 RPM is reached (CFM Vol. II Chapter 17)
17-13) What is the maximum in flight propeller RPM setting?
1020 PRPM (CFM Vol. II Chapter 17)
17-14) How do you manually feather the propeller?
Manual feather of the propeller is accomplished by selecting the respective condition lever to the start and feather gate (CFM Vol. II Chapter 17)
17-15) What happens if the propeller system loses oil?
The propeller blade natural twisting moment created by the counterweights will result in the propeller seeking a coarse pitch setting. (CFM Vol. II Chapter 17)
17-16) What is the auto feather delay?
A three (3) second delay is placed in between engine failure and activation of the auto feather (CFM Vol. II Chapter 17)
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