Powerplant Flashcards
When will FADEC generator start powering the FADEC?
35% HP.
At approximately 35% HP, a Permanent Magnetic Alternator (PMA), driven by the engine’s accessory drive gearbox, provides electrical
power to the EEC’s and FADEC’s.
What is the backup power supply to the FADEC (if FADEC generator fails, or RPM too slow for that generator to provide power)?
L and R ESS DC Buses
A Blue CAS “Engine Start Protect L-R” means what?
Indicated engine FADEC is automatically commanding extended time for monitoring engine (20 minutes to 5 hours) prior to introducing fuel to the engine for start. 10 - 30 second crank to reduce wobble from partially-cooled drive shaft.
Name some of the components driven by the accessory gear box.
IDG Fuel Pump Fuel Monitoring Unit (FMU) Hydraulic Pump Oil Pump Engine Breather Air Turbine Starter PMA
What happens to the spinner on the face of the LP if ice accumulates during engine operation?
The soft rubber tip distorts and provides passive ice shedding.
What happens to engine during water ingestion?
Bleed handling valves are commanded OPEN, continuous ignition is selected ON automatically, and engine idle speed is increased to ensure engine stability and allow water to pass into bypass flow.
Primary function of Engine Vibration Monitoring System (EVMS) is to monitor the balance of rotating assemblies in the engine in order to detect possible mechanical failure. How many sets of probes are used?
Two (2) sets of probes (one primary and one secondary) to measure amount of rotation on both LP and HP rotating components
When should an engine be shut down for abnormal EVM indications?
If vibration is accompanied by other failure indications
How is EPR derived and what happens with a loss of EPR?
It’s a ratio of outlet over inlet pressure. The engine reverts to ALT control with loss of EPR.
What’s the primary purpose of Fuel Cooled Oil Cooler (FCOC)?
It enables engine oil to heat fuel and prevent formation of ice crystals in LP filter and FMU. It also cools the oil.
What happens during engine shutdown if capacity of drains tank
(environmental container) is exceeded?
Fuel is dumped overboard
When does Fluid Quantity Indicator (FQI) take a snap shot of
oil quantity and store it as a historical reading?
5 minutes after shutdown
How does FADEC alternate channels for consecutive ground starts?
It changes channels every time you cycle FUEL CONTROL switch and changes exciters/igniters every other time unless there’s a start anomaly.
True/False: When normal ground start attempt is aborted due to anomalies, FADEC automatically selects the other igniter on the following normal ground start attempt.
True
True/False: Ignition systems are capable of being continuously energized by pilot selection of continuous ignition.
True. There’s no time limitation; however, continued or very frequent use shortens igniter life.
Which type of engine start uses just one igniter?
Normal ground start including crossbleed start and engine start – battery power only.
Both igniters are used for alternate engine ground start and all air starts as well as inclement weather mode, auto-relight, and quick relight.
What happens when you select MASTER START switch to ON?
It signals FADEC to arm the automatic start sequence for start valve and ignition, opens isolation valve and shuts off the right pack.
During engine start, when would you expect Starter Air Valve
(SVO) and IGN icons to extinguish?
Approximately 44%
What’s the caution associated with opening the starter air valve manually?
Wear high temperature gloves and exercise caution.
Under what conditions would you use the Manual Airstart –
Windmilling procedure?
If starter was inoperative.
Name the three (3) airstart procedures
Normal Airstart – Automatic,
Manual Airstart – Starter-Assist
Manual Airstart – Windmilling
What’s the auto-relight mode?
It’s automatically initiated by FADEC for engine flameout and rundown. In this mode, FADEC energizes both igniters continuously and schedules fuel flow until rpm stabilizes.
What’s the quick relight mode?
Provides a means of automatically relighting the engine if FUEL CONTROL switch is selected to OFF position and then reselected to RUN position within 30 seconds.
When activated, fuel is commanded on and both ignition systems are switched ON.
What are the requirements for engaging autothrottles on takeoff?
Valid EPR rating selected, valid speed target selected, and > 1.05 EPR
Why do autothrottles go into hold mode at 60 kts during takeoff?
Autothrottle servos are deenergized to prevent unwanted thrust reductions during critical takeoff between 60 kts airspeed, rotation and climbout to 400’ AGL.
When does autothrottle system come out of hold?
400’ AGL
What happens if you push TO/GA during a fully coupled two engine ILS approach?
Go-around is commanded (initial 9° pitch up and wings level), both autopilot and autothrottles remain engaged, power levers advance to go-around power, and FMS sequences to missed approach procedure.
Name the three idle settings.
Flight
Approach (i.e., high idle)
Low or ground idle
What’s the requirement for approach idle?
Flaps > 20°, aircraft in flight and no wheel spin-up
What’s the downside to alternate
control mode?
You lose FADEC protection, you lose autothrottles, and you can’t dispatch in alternate control.
When would thrust reversers be available after landing?
With wheel spin-up or weight-on-wheels
Were thrust reversers considered for landing distance certification?
Not on dry runways. They were considered for Wet.
How is the engine controlled in reverse thrust region?
LP
Describe thrust reverser indications.
White REV – unlocked
Green REV – fully deployed (maximum reverse thrust available)
Amber REV – uncommanded deployment on the ground: engine limited to idle
Flashing red REV – deployment in flight: engine limited
to idle
