Engine Flashcards
How is the FADEC normally powered?
Above approximately 50% N2 the FADEC is powered by the Permanent Magnet Alternator (PMA). Below this value or in case the PMA becomes inoperative; the airplane’s electrical system provides the backup power. (B12 14-06-30 Pg 2)
DCC ESS BUS 1 + 2 provide backup power to FADEC (B1214-05-35 Pg 9 & 13)
On take-off, what indications will show that ATTCS has engaged?
A GREEN ATTCS indication is displayed to indicate the Automatic Takeoff Thrust Control System has engaged on the EICAS. The engagement only happens when the thrust levers reach the TO/GA set position.
(B12 14-06-05 Pg 5 & 7 and 14-06-30 Pg 2)
What does the cyan V bug indicate on the N1 gauge?
N1 Target Indication - A cyan V-shaped bug represents the N1 target on the dial indicator. (B12 14-06-05 Pg 5 & 6)
When does the ITT red line change to amber?
The red line will change to amber after the end of the takeoff phase. The red line will be shown in flight if the ITT goes above the CON thrust rating limit. (B12 14-06-05 Pg 5 & 8)
In certain conditions, a CYAN line will appear on the edge of the N1 indicator. Why and what for?
N1 WING ANTI-ICE CYAN LINE
Displayed only in icing conditions during final approach (radio altimeter below 1200 ft) with landing gear down or flaps extended. Indicates the minimum thrust level (N1 value) to meet bleed requirements.
(B12 14-06-05 Pg 5 & 6)
During an auto relight in flight, what indications would you expect to see next to the N2 indication?
A green WML icon is displayed whenever the FADEC has detected an engine flameout and the auto re-light system is actuating to restart the engine. (B12 14-06-05 Pg 5 & 8)
During ground starts, what protection does the FADEC provide?
The FADEC provides engine start protection on the ground as follows:
- Hung start .
- Hot start .
- No light-off
(B12 14-06-30 Pg 11)
What happens if ATTCS is not selected to the ON position on the T/O data set page of the MCDU during take-off?
In the case of two engines operating, or one engine failure, at T/O with ATTCS off and TLA at TOGA or MAX, there will be no thrust increase to T/O RSV.
NOTE: With Windshear on T/O and TLA is MAX, GA RSV is set by the FADEC.
(B12 14-06-30 Pg 4)
How many idle mode selections are there?
The idle mode selections are the following:
- Flight Idle.
- Approach Idle.
- Final Approach Idle.
- Ground Idle.
(B12 14-06-30 Pg 7)
How many channels does the FADEC have and when do they change in normal operation?
The FADEC has two identical but isolated channels. One operates as the in-control channel and the other as a standby. The standby channel constantly processes all the data and is always ready to take control of the engine in case the active channel fails. The FADEC in-control channel is switched on every engine start.
(B12 14-06-30 Pg 1)
Normal engine shutdown on the ground is possible with the associated thrust lever at maximum ___ above the IDLE position
5 Deg
When is the N1 Wing Anti Ice Cyan line displayed? and what does it indicate?
Displayed in Icing conditions when radio altimeter is below 1200ft with landing gear down or flaps extended
Indicates the minimum thrust level (N1 value) to meet bleed requirements
What does the N1 TARGET INDICATION show?
Maximum N1 for the engine thrust rating mode indicated on EICAS
What is the normal operating range of the engine vibration indication? and the cautionary operating range?
Green: 0 to 3.9
Caution: 4.0 to 5.0
Upon exiting the fuel tanks, what happens to fuel in terms of pumps?
It first flows through the low pressure pump and then divides into two paths.
1) one flows through the high-pressure fuel pump and returns to the fuel tank as motive flow.
2) The second flows through the fuel/oil heat exchanger to the high-pressure fuel pump. The flow leaves the pump and passes through the fuel filter. Once filtered, the fuel flows to the FMU.
What does the fuel/oil heat exchanger do?
Maintains oil temperature within an acceptable range and heats the engine fuel to prevent freezing.
What does the Fuel metering unit do? (FMU)
What is it controlled by and what valve does it control?
Controlled by the FADEC, meters and distributes the proper amount of fuel.
Controlled by FADEC controls Shutoff Valve used during normal shutdowns and provides overspeed protection.
What does the variable stator vane system consist of?
What is there purpose?
Two fuel driven actuators controlled by the FADEC via the FMU.
Optimise the position of the compressor stators as a function of corrected N2 to provide optimum compressor efficiency
What does the oil system cool and lubricate?
- Turbine engine main shaft
- Bearings
- Accessory gearbox
What does the oil pump contain?
1 supply and 4 scavenge pumps
What does the oil filter contain to help with cold starts?
Relief valve to bypass high viscosity oil during cold start conditions
What does the engine starting system consist of?
- Air turbine starter (ATS)
- Starter control valve (SCV)
How many ignitors are energised for on ground engine starts and in flight engine starts?
on ground 1 ignitor
in flight 2 ignitors
The FADEC initiates ignition at what N2 %? and the fuel flow?
Ignition 7% N2
Fuel flow 20-25% N2
The FADEC has no protection against what in flight?
Hot starts, hung starts or failure to light off for in flight engine starts
In case of thrust reverser fails what happens when selecting both reversers? What happens when you select the single operative reverser?
With both - Operative thrust reverser provides minimum reverse thrust.
With the operative reverser it enables maximum reverse thrust to the engine.
What does the engine control system consist of?
- FADEC
- Thrust Lever
- T2 and N1 sensors
What are some of the functions of the FADEC?
- Engine protection
- Control of the requested and Max N1
- Control of the ATTCS
How many channels does the FADEC have?
2 channels
Above approximately 50% N2 the FADEC is powered by what? Below this value or in case this becomes inoperative, what provides backup power?
Above 50% N2 - Permanent Magnet Alternator (PMA)
Below this value or if it fails - Airplanes electrical system provides backup power
What is ATTCS?
Automatic Takeoff Thrust Control System
When does the ATTCS automatically command Reserve thrust (RSV)?
The ATTCS automatically commands RSV whenever it is engaged, thrust levers are at TO/GA position, and one of the following occurs:
- Difference between both engine N1 values is greater than 15%
- One engine failure during T/O
- One engine failure during go-around
- Windshear detection
Are all T/O modes eligible for flexible TO? is it possible with ATTCS?
Yes and Yes
What is the minimum flex T/O thrust?
75% maximum rated T/O thrust or CLB-2 + 1% N1, whichever is HIGHER
If a flex T/O is used, what happens when you move the thrust levers to MAX?
Resets the assumed temperature and sets the maximum thrust available
The FADEC calculates the maximum N1 for each thrust rate mode adjusted for?
- Altitude
- temperature
- airspeed
What are the flight idle modes?
- Flight Idle
- Approach Idle
- Final Approach Idle
- Ground Idle
When is approach idle activated? and what is it?
- In flight
- Altitude less than 15000ft
- Flaps 1 or greater or landing gear down
Enable rapid acceleration to GA thrust
When is final approach idle activated?
- Altitude lower than 1200ft AGL
- Landing Flaps
- Landing Gear down
What is ground idle?
Minimum thrust setting thats stable for ground operations
What engine start protections does the FADEC provide on the ground?
- Hung start
- Hot start
- No Light-off
What value of N2 will the FADEC automatically command engine shutdown?
In the event of how many overspeed detection events will the FADEC not relight the engine?
102%
3
During Engine start if the ITT reaches its limit the FADEC automatically does what?
Is the start control valve automatically closed?
Shuts off the fuel flow aborting the start sequence
No, pilot intervention is needed to close the SCV be selecting the START/STOP switch to STOP
One engine ground starts the FADEC will not allow fuel flow if ITT is above?
120C
What is the indication that ATTCS is activated?
The green ATTCS indication on the EICAS disappears and the cyan thrust mode will be displayed with an additional “RSV” indication
How can you reset reverse thrust to get max from the operative engine if one has failed?
Move both thrust reversers back to idle to reset the system and allow reverse on the No 2 engine
What does the Amber line in the ITT graphical representation indicate?
The Amber line indicates the maximum allowable ITT for the current flight phase
For in-flight engine starts, what is the maximum cumulative starter run time per start attempt?
120 seconds
At what point does the FADEC de-energize the Start Control Valve (SCV)?
50% N2.
What does an Amber REV displayed below the N1 indication dial represent?
An Amber REV indicates reverse cowl is in transition
What is the normal range for engine LP vibration?
The normal range for engine LP vibration is 0.0 to 3.9
What is the maximum ITT when starting the CF34-10 F engine?
The maximum ITT when starting the CF34-10 F engine is 740
What is the maximum ITT during take off?
The maximum ITT during take off is 983 C
What is the minimum oil pressure for the engine?
25 psi
What does the Cyan V bug indicate on the N1 dial?
The Cyan V bug indicates the target N1 setting for takeoff.
What oil sumps are associated within the engine lubrication system?
A Sump, B Sump, C Sump, and the AGB Sump
How many Full Authority Digital Electronic Controls (FADEC) are assigned to each engine?
One
How many igniters are used for engine starts?
One, alternates each ignitor for each engine start
This is confirmed in B12 14-06-01 Pg 11.
Maximum ITT when starting the engine?
740C
Maximum ITT during TO?
983C
What is the normal range for the engine LP vibration?
0 - 3.9
For engine ground starts, what is the maximum cumulative starter run time per start attempt?
90 seconds
What does the CYAN V bug indicate on the N1 dial?
N1 Target set via Data set on the MCDU
What is the basic construction of the engine?
Hi-Bypass Turbo Fan with Single-stage Fan. 10 stage axial core. 2 stage high pressure turbine. 4 stage low pressure turbine.
