Power Plant Flashcards
When the Engine is running, what causes the Igniters to operate automatically?
EIU failure, flame-out detected and after the second start attempt failed
What does FADEC do following an Automatic Start Abort?
Hot, Hung, Stall, No Light-off
Runs an abort sequence, if a start aborts on the ground, the FADEC:
Closes the HP valve.
Closes the start valve.
Turns off ignition.
Cranks the engine, after the start abort in order to clear out fuel vapours.
Controls any additional start attempts.
During a Normal (Auto) Start what happens at 16%, 20%, 55% and 63% N2?
@ 16% ignition starts (on ground)
> 20% HP fuel valve opens -> EGT increases -> N1 increases
55% Ignition stops
63% Start valve start closing
- APU speeds returns to normal
- Pack valves reopen if another engine is not started within 60 sec.
Which is the only malfunction, which will cause an auto-abort of an Engine MAN START?
On the ground, if the start EGT limit is exceeded before reaching 50% N2, the FADEC aborts the start, in this case only.
Man Start: When should the MSTR switch be selected ON?
At max N2, at least 20%.
Man Start: What happens when the MASTER switch is selected ON?
Both igniters comes, LP + HP fuel valves open, when N2 > 63% start valve closes and if on the ground, ignition stops. APU speed returns to normal if APU was used.
Man Start: what closes the start valve? And When?
FADEC at approximately 63% N2, on the ground, then cutting off the ignition.
What causes the FAULT light to illuminate on the engine panel?
Amber light comes on, caution appears on ECAM, if there is an automatic start abort, a disagreement between the HP fuel valve position and its commanded position, or a malfunction of the thrust control.
What do MAN START pushbuttons control?
ON: start valve opens if the ENG MODE selections is set to CRANK or IGN/START and N2 < 20%, both packs valves close during the start sequence, start valves closes when N2 > 63%.
What is at one end of the TRANSIENT N1, and what is at the other?
Actual N1 (Green) and N1 command (N1 trend) in green.
On the EGT what does the amber index indicate?
The amber index appears at 750 degrees during engine start, then 1025 degrees (max EGT).
What does REV in amber / green indicate?
Amber: when nay one blocker door is unstowed or unlocked.
Green: when all four doors are fully deployed.
How can you tell that the Start Sequence has finished?
Amber arc increases from 750 degrees to 1025 degrees (max start – max continuous EGT).
Grey background N2 box disappears.
AVAIL indication on N1 indicator (10 sec steady on ground, 1 min pulses in flight)
When does IDLE indication appears (between the N1 gauges)?
When both engines are idle, and in flight. Pulses for 10 sec and then remains steady.
When is FUEL USED set to zero?
The green number is computed by the FADEC, it resets when the engine starts on the ground.
What are the limiting EGT, and operating time, at TOGA power?
1060 degrees: 5 mins (2-engines) or 10 mins (1-engine)
What are the starter limitations?
3 consecutive cycles, 60 sec pause between each cycle
(Maximum 2 min start cycle time for manual start)
No running engagement of the starter when N2 is above 63%
15 min cooling period, following 3 failed cycles
What is the minimum IAS for Full Reverse Thrust?
70kts
Why should Engines be operated at Idle for several minutes before take-off?
> 3 mins to ensure centre tank pump test finished, engine wear, to prevent thermal shock.
When, and for how long, are FADECs powered?
First 5 mins after aircraft is powered, then self-powered above 10% N2 until 5 mins after 2nd engine shutdown.
What is on the N1 shaft?
Fan, LP compressor and LP turbine
What is on the N2 shaft?
HP compressor and HP turbine
What is on the accessory gearbox and what are they powered b
Fuel PumpOil PumpAlternatorPowered by the N2 shaft
What are the functions of the FADECs?
Fuel flow, thrust reverser and ignition controlN1, N2 and EPR limits protectionEGT limits protectionStarter engagement time and speed protectionFuel and Thrust limit computationsComputation of thrust penaltiesAccelleration and deceleration schedulesIdle settingsEngine information to cockpit
What does the FADEC control during ground starts?
Controls start sequenceProvides full protectionsHas start abort authority
What FADEC feature is only available during ground starts?
Start abort authorityEGT protection
What does the FADEC do during manual starts?
Monitors and provides cautions and warnings
What are the 3 idle settings?
Modulated Idle: on ground and in-flight when slats retracted (lowest idle, long spool up times)Approach idle: in-flight when slats are extended (low spool up time for go arounds)Reverse Idle: REV IDLE position (slightly higher than modulated idle)
How is (EPR) Engine Pressure Ratio calculated?
P5 (LP turbine exhaust) vs P2 (engine inlet pressure)
What are the 2 modes of the FADEC for setting thrust?
EPR (Engine Pressure Ratio)N1
When the FADEC regulates thrust in EPR mode, what are the pa
Thrust Lever Angle (TLA)AltitudeMach NumberAmbient TemperatureAir inlet total temperatureAir bleed demands
When EPR mode fails, the FADEC reverts to N1 mode. What impo
No AutothrustNo Alpha Floor
What are the 2 types of N1 mode?
Rated N1 modeUnrated N1 mode
What is the difference between Rated and Unrated N1 modes?
Rated N1 Mode: N1 limits and protections are displayed on E/WD, can be selected manuallyUnrated N1 Mode: Used with EPR and Rated N1 mode failures. N1 limits not displayed and FADEC provides limited overspeed protection. (emergency)
What is the redundancy within the FADEC?
Channels A and B provide backup and redundancy
When does the engine alternator provide power to the FADEC?
N2>10%
How is the IDG and Engine Oil cooled?
By heat exchange with the fuel
When does the FADEC command continuous ignition?
ENG ANTI ICE ONTake off thrust selectedEngine Interface Unit (EIU) failsApproach Idle (slats extended)Engine flameout or surge detectedENG MASTER cycled on-off-on
What type of reverse thrust is used?
Translating Sleeve, which redirects Fan Air only
What does the thrust reversers require prior to activation?
At least 1 FADEC channel opLanding Gear Control and Interface Unit (LGCIU) detects aircraft is on the ground.
When would you get a FAULT light on the engine control secti
Auto start is abortedStart valve faultHP fuel valve not in commanded position
What does the IGN/START switch do?
Manually selects continuous ignitionPrepares the engine for the start process
What does the CRANK switch do?
Prepares the engine for dry cranking (no ignition or fuel flow)Starter will engage when MAN START is selected
How long is TOGO powered limited to?
5 minutes
What is the speed limitation of Max Reverse?
Max reverse should not be used below 70 kts
What are the 2 auto-thrust modes?
Armed: during TOGO or FLX or when Thrust levers not in active range (between CLB and IDLE)Active: pushing the FCU A/THR pb
When auto-thrust is activated, what do the levers do?
The lever now become thrust limiters, therefore us leave them at the CL detent to give auto-thrust full authority.Note: the exception is when Alpha Floor is activated in which TOGA power is activated regardless of lever position
How can you disengage auto-thrust?
Disengage buttons on the leversSelecting A/THR pb offMoving the thrust levers to idle (landing)
The amber tick mark on the EGT gauge is the calculated max E
TOReverseAlpha floor
What is the red tick mark on the EGT gauge?
Highest value achieved
What does a + by N1 mean?
N1 went above 100%
When will the oil pressure be amber?
<80psi
When will the oil pressure be red?
<60psi
When will oil temp be amber?
> 155C
When will oil temp be red?
> 155C for 15 minutes or >165C
When will vibration pulse?
5 units
Which engine is started first and why?
2 because it provides pressure for the yellow hydraulic system which provides parking brake pressure
What is the memory air for ensuring a stabilized engine star
2,4,6,8,1020% N1400 EGT60% N2800 Fuel Flow1.0 EPR
Why would you manually start an engine?
To allow the engine to reach its max motoring speed prior to ignition and fuel flow
When is a manual start recommended?
Engine StallEGT overlimitLO START AIR PRESSNo N1 rotationHungstartIGN A/B Fault
What is the minimum N2% required for a manual start prior to
15% N2
When does the FADEC close the start valve?
N2 between 43-48%
What are the advantages to a FLEX TO?
Extending engine lifeless fuel
What does the FADEC do to reduce Fan Flutter?
Prevents N1 from stabilizing 60-74% N1, thus when you advance thrust levers, it will skip this range
What EPR valve do you aim for to ensure proper engine indica
1.1 EPR
When shutting down the engine using the ENG FIRE button what
Only the LP fuel valve is closed causing a 40 second delay as the fuel in the line is burned.
When will the FADEC abort a start on the ground and indicate
Starter time exceededEGT overtempNo light offLower than normal N1Starter failureHung Start
How can you tell if the FADEC reverted to UNRATED N1 mode?
Loss of the max N1% tick mark
At what OAT would you select TOGA rather than FLEX?
When FLEX temp is within 10 degrees of OAT to avoid asymmetrical thrust (EPR/N1 discrepancy)
When does the self powering of the FADEC start?
IAE Engines
The FADEC system is self-powered above 10% N2. In case of a FADEC self-power loss the aircraft electrical network automatically supplies the FADEC.
What is the function of the fuel metering valve (FMV)?
IAE Engines
The FMV controls the fuel flow protects against overspeeding controls the shut off valve and supplies high pressure fuel to the various actuators.
How does the ignition system work?
IAE Engines
The ignition system is used to start the engine on ground and to restart it in flight. it consists of two identical independent circuits for each engine normally controlled by the FADEC channel A with channel B on standby. Each FADEC channel can control both igniters.
The FADEC system performs the following functions…
IAE Engines
Control of gas generator protection against engine exceeding limits power management automatic engine starting sequence manual starting sequence thrust reverser control fuel recirculation control transmission of engine parameters and engine monitoring information detection isolation and recording of failures FADEC cooling and protection against fan flutter.
How does the engine start system work?
IAE Engines
The engine start system consists of an air turbine starter and a start valve. The start valve admits air supplied by the pneumatic system to operate the starter. The FADEC controls the start valve electrically. If electrical control fails when the aircraft is on the ground a handle allows the start valve to operate manually.
How many thrust lever positions are there and how are they labeled?
(IAE Engines)
There are 5 thrust lever positions: TO/GA, FLX/MCT, CL, IDLE and MAX REV.
Is a N1 mode available?
IAE Engines
If no EPR is available (either sensed or computed) the affected FADEC will automatically revert to N1 mode.
How does the protection against fan flutter work?
IAE Engines
When on ground at low speed the EEC protects against fan flutter. In so doing the EEC prevents the engine from being stabilized between an approximate range of 60% to 74% N1 (depending on the outside air temperature). Therefore during engine acceleration on ground the pilot may notice a non-linear thrust response to thrust lever movement.
What are the main components of the oil system?
IAE Engines
The oil system contains the oil tank the lube and scavenge pump modules the fuel/oil heat and air/oil heat exchangers the filters chip detectors pressure relief and bypass valves.
How many channels has the FADEC?
IAE Engines
The FADEC has two-channel redundancy with one channel active and one channel in standby. If one channel fails the other automatically takes control.
What is the purpose of approach idle?
IAE Engines
Approach idle allows the engine to accelerate rapidly from idle to go-around thrust.
When does the oil temperature indication become amber?
IAE Engines
These numbers are normally green. They become amber and an associated warning appears on the ECAM if the temperature exceeds 165°C or exceeds 155°C for more than 15 minutes or is below -10°C.
What are the idle modes of the FADEC?
IAE Engines
Modulated idle approach idle and reverse idle.
What is the main parameter to control the engine thrust?
IAE Engines
The engine thrust setting is made through the control of the Engine Pressure Ratio (EPR).
What is the function of the fuel oil heat exchanger?
IAE Engines
The fuel oil heat exchanger enables fuel to be heated by the oil to reduce temperature of the oil and prevent fuel icing.
What are the components of the engine oil system?
IAE Engines
The oil tank the lube and scavenge pump modules the fuel/oil heat exchangers the filters chip detectors pressure relief and bypass valves.
How does the reverse thrust system work?
IAE Engines
The reverse thrust is obtained by deflecting the fan airstream. This is done when the translating sleeves are fully deployed rearward thus enabling the pivoting blocker doors to forward divert the fan flow through the cascades.
Take off can be done using which power settings?
IAE Engines
FLEX/MCT and TO/GA.
What are the primary parameters on the upper E/WD display?
IAE Engines
EPR, EGT and N1.
When is approach idle selected?
IAE Engines
Approach idle is selected in flight when the flaps are extended (FLAPS lever not at zero position).
What is the purpose of engine ventilation (dry cranking)?
IAE Engines
A dry cranking cycle ventilates the engine to remove fuel vapours after an unsuccessful start attempt on the ground. The flight crew can manually select cranking by setting the ENG MODE selector to CRANK and the MAN START pushbutton to ON (MASTER switch OFF).
