Engines Flashcards
How long can you use MCT?
RTFQ!!
Max CONTINUOUS thrust - no time limit
(Until you run out of fuel?!)
How many FADECs are there?
Full Authority Digital Engine Control System
2 (1 per engine)
Does the FADEC still operate in the event of a pwr failure?
Yes
Each engine has an alternator which powers the FADEC (when required)
How many igniters are used to start the engine in normal conditions?
How many igniters are used to start the engine after 1 engine start?
After each start attempt, what is the fuel required to start reduced by, as a percentage?
How many starts will the FADEC attempt in a start sequence?
1 (automatically alternates for each sector)
2
7%
4
Engine start process (on the ground)
LP fuel valve opens
Airflow (engine start valve opens)
>16% N2 - ignition
>22% N2 - fuel in (hp fuel valve opens)
EGT increases
>50% N2 - engine started (engine start valve closes, igniters off)
What are the 3 idle engine modes?
Modulated
Approach
Reverse
Modulated idle…
In flight when flaps are retracted
On the ground without reverse thrust selected
Regulated according to bleed system demand and ambient conditions
Approach idle
Regulated according to aircraft altitude, regardless of bleed system demand
Selected in flight when the flaps are extended (Flap lever not in zero position)
Slightly higher setting allowing lower spool up times
Reverse idle
Selected on the ground when thrust lever is in REV IDLE position
Slightly higher than fwd idle
Time limit for
2 ENG TOGA
1 ENG TOGA
5 mins
10mins
2 eng thrust lever range
Single eng thrust lever range
Idle to climb
Idle to MCT
Electrical pwr priority
A/C gen (eng driven)
GPU
APU
Estimated oil consumption
0.5 qt/h
How many FADEC channels?
2
1 active, 2nd standby
What is the HMU?
Hydromechanical unit
Controls fuel flow to the engine combustion chamber
Controls fuel hydraulic signals to actuators
Protects against over speeding
FADEC protections
Hot start
Hung start
Wet start (failure to light)
Surge (stall)
What generates thrust?
N1 (70%)
Turbine (30%)
What does the FADEC use to calculate thrust?
N1 (fan speed)
If you set the ENG MASTER lever to OFF in flight how does the engine shut down?
LP and HP fuel valves close
Does the ENG MASTER need confirmation to shut down?
YES
Where do you see N1 & N2?
E/WD
EGT RED line limit?
950°C
EGT AMBER line limit?
725°C during eng start on the ground, or
915°C in all other cases
note: The EGT limit does not appear when:
T/O or G/A selected
Thrust reverse selected
Alpha floor protection activated
Minimum oil temp for takeoff?
-10°C
How is the accessory gearbox driven?
HP rotor shaft
How are the IDGs cooled?
Integrated Drive Generators
Using fuel from the HMU
Fuel returns to the pump or tank (via the FRV)
What type of engine?
High bypass turbofan
Where is the FADEC located
4 o’clock position
What temperature is the fuel returned to the tank via the FRV?
<100°
Max fuel temp (for fuel return) 52.5°
