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