Engine Flashcards
What kind of the engine does A321 have ?
Jet Engine with high by pass ratio
What does “High by pass ratio” mean ?
Air goes into engine is divided into flows
* Most of the air flows out of the engine core, and provide most of engine thrust
* The remain air enters the core engine
The air which provide most of the engine thrust is call by pass air
What is N1 ?
Rotation speed of the fan
What is N2 ?
Rotation speed of HP rotor
How many igniter does an engine have ?
Each engine has 2 igniters, locate inside combustion chamber
What is the function of accessory gearbox ?
Drives various accessories with mechanical power via HP shaft
* Oil feed pump
* Fuel pump
* Hydraulic pump
* Generator
* FADEC alternator
* Pneumatic stater
What redundancy does FADEC have ?
Full Authority Digital Engine Control
2 channels, one active, one stby
What is the power source for FADEC ?
Full Authority Digital Engine Control
FADEC has its own magnetic alternator.
If alternator fails, a/c electrical system will power FADEC
What is the function of EIU ?
Engine Interface Unit
Transmits to FADEC the data it uses for eninge management
Infor from
- Zone cont
- LGCIU
- BMC
- FCU
- FMGS
How does “Protection again fan flutter” funtion work ?
CEO a/c only
On ground at low speed, EEC prevents engines from stabilized btw 60% and 74% N1( depend on OAT)
Electronic Engine Computer
What are FADEC tasks during manual start sequence ?
- passive monitor engine
- control of
* start valve
* HP fuel valve
* Ignition
What is the different btw auto start and manual start ?
- During auto start FADEC control and monitor the sequence include auto crank
- During manual start, pilot have to monitor engine parameter, FADEC only control the start valve, HP fuel valve, and ignition. Cranking has to be done manually also.
How many idle mode does FADEC have ?
CEO a/c
Modulated Idle
Approach Idle
Reverse Idle
How many idle mode does FADEC have ?
NEO a/c
Minimum Idle
Approach Idle
Reverse Idle
What is minimum idle mode ?
NEO a/c
Is regulated according to
* Bleed system demand
* ambient condition
Is selected
* In flight when LDG is retract and not in config 3 or full
* On ground, provide reverse is not selected
What is approach idle mode ?
NEO a/c
- Is selected according to a/c alt, bleed demand and ambient condition
- Is selected in flight, in CONF 3 or Full or LDG is down
- Allow engine to accelerate rapidly from idle to GA thrust
What is reverse idle mode ?
Both NEO and CEO
- Is selected on ground when thrust lever in REV IDLE position
- Is slightly higher than foward idle thrust
What is modulated idle mode ?
CEO a/c
Is regulated according to
* Bleed system demand
* ambient condition
Is selected
* In flight when Flap at zero
* On ground, provide reverse is not selected
What is approach idle mode ?
CEO a/c
- Is selected according to a/c alt, bleed demand and ambient condition
- Is selected in flight, when flaps extend
- Allow engine to accelerate rapidly from idle to GA thrust
What is detents and stops ?
Thrust lever
Detents
* MCT/FLEX
* CLB
* REV IDLE
Stops
* TOGA
* IDLE
* REV MAX
How does FADEC compute thrust rating limit ?
Depend on thrust lever position
* If thrust lever is set in a detent, FADEC selects the rating limit corresponding to this detent
* If thrust lever is set btw 2 detents, FADEC selects the rating limit corresponding to the higher detent
How many power setting does FADEC have ?
CEO
- N1
- EPR
What is N1 mode and EPR mode ?
CEO
EPR is normal mode
N1 is rated or degraded mode
Loss A/THR and Alpha Floor during N1 mode
EPR = Low pressure turbine exhaust press (P5) / Engine inlet press (P2)
What is N1 rated mode ?
CEO
FADEC will determine N1 power setting as a function of TLA, altitude and engine inlet total temp
Thrust Lever Angle
What is N1 degraded mode ?
CEO
N1 is define by function of TLA only
Thrust Lever Angle
When will FADEC revert to N1 rated mode ?
CEO
When P2 (engine inlet pressure) and P5 (low pressure turbine exhaust press) are not avail
When will FADEC revert to N1 degraded mode ?
CEO
- When loss T2 (engine inlet total temp) or ambient pressure (ambient pressure engine sensor) parameters
- Emer Elec Conf
How to revert back to EPR mode from N1 mode ?
CEO
Switching OFF the ENG N1 MODE pb
only work if the failure has dissapeared
What are the composition of fuel pump unit in engine ?
CEO
Consists of low and high fuel pump
What is the function of Fuel Oil Heat Exchanger ?
CEO
Heat the fuel, cool the oil
What is the function of fuel metering unit ?
CEO
FADEC control fuel supply via FMU
Fuel Metering Unit
For NEO is IFPC (Integrated Fuel Pump and Control)
How is IDG oil cooled ?
CEO
Via IDG cooler
Also by engine fuel
How many operation mode does IDG cooling recirculation system have ?
CEO
- 2 Return to tank mode
- 2 No return to tank mode
What are the components of oil system ?
CEO
- Oil tank
- Lube and scavenge pump modules
- Fuel/oil heat and air/oil heat exchanger
- Filter, chip detector, pressure relief and bypass valve
NEO has additional
* Oil pump for HP and LP rotors
* Oil pump for FDGS
What is the cooling method for engine ?
Active clearance control for the high and low pressure turbine blade tip clearance by cooling the related turbine case
What is the method to keep engine stability ?
By control the airflow through HP and LP compressure via valves which is installed in different stage of compressor
How can engine create reverse thrust ?
Translating sleeves are fully deployed reaward, thus enabling the pivoting blocker doors to forward divert the fan flow through cascades
What are the deploy requirement for reverse thrust ?
- One FADEC channel
- Right and left main gear compressed signal from corresponding LGCIUs
- TLA reverse signals from at least one SEC
What is the protection method for reverser system ?
FADEC will automatically select thrust to idle in case of
* Inadvertent deploy
* Inadvertent stowage
What is the component of engine ignition system ?
It consists of two identical independent circuit, which is controlled by FADEC
How many igniter supply for auto start ?
One and FADEC automatically alternates the igniters and/or channel used in successive sequence
How does ignition come on and off ?
CEO
Auto start
Ignition come on automatically after dry crank and cut off automatically when N2 reach 43%
Manual start
When ENG MASTER is ON
How does ignition come on and off ?
NEO
Auto start
Ignition come on automatically after N2 reach 18% and cut off automatically when N2 reach 55%
Manual start
When ENG MASTER is ON
When do both igniters come on for starting ?
- Manual start
- Relight inflight
When does continuous ignition come on automatically ?
CEO
- Engine flameout or surge detected
- Quick relight
- ENG ANTI ICE pb ON
- Approach idlle is selected
- GA with slats/flaps
- EIU failed
What are the components of engine starter ?
- Air tubine starter
- Start valve
How to open starter valve when electrical fails ?
a handle allows the valve to be open manually
What happen when automatic start failed ?
FADEC will abort the sequence and dry crank the engine
auto start
What happen when ENG MODE selected IGN/START ?
- ENG page appears on SD
- All engine parameters are avail
- Pack valves auto close
After 30s if ENG MASTER lever not ON, pack valves auto open
auto start
What happen when ENG MASTER ON ?
CEO
- LP fuel valves open
- Start valve open
After dry crank (30s) - ignition start
- HP fuel valves open
auto start
What happen when ENG MASTER ON ?
NEO
- LP fuel valves open
- Start valve open
After dry crank (2min) - ignition start
- HP fuel valves open
Manual start
What happen when ENG MODE selected IGN/START
ENG MAN START pb ON ?
Start valve open
Manual start
What happen when ENG MASTER ON ?
- HP valve open
- Both igniters on
How to turn off igniter and close start valve during manual start ?
CEO
FADEC do it automatically when N2 reach 43%
NEO 55%
What “COOLING” memo displayed on E/WD mean ?
Engines are cranking
Why do we need to crank the engine after failed start attemp ?
Cranking helps ventilate the engine to remove fuel vapors on ground
Can enigne be crank inflight ?
NO
How to perfrom wet crank process ?
- ENG MODE select CRANK
- ENG MASTER ON
- ENG MAN START ON
ENG FAULT light?
- HP fuel valve in abnormal position
- Automatic start aborts
- Malfunction of thrust control
What does “REV” in amber mean ?
Thrust reverser system is unlocked
What does “REV” in green mean ?
Thrust reverser system is fully deployed
What happen when hold A/THR instinctive disconnect pb > 15s ?
A/THR will be disconnected for the rest of the flight
Where can you find thrust reduction alt and is the number always the same ?
PERF page on MCDU, number can be modified
Which pb control the LP fuel valve ?
ENG MASTER switch
Which thrust lever position must be in, in order to active A/THR ?
- CLB for both engines
- MCT for OEI
T/O can be done using which power setting ?
- TOGA
- FLEX
What happen when you selected FLEX without set flex temp into MCDU ?
MCT setting will be in used