Engine Flashcards
What types of engines are on the aircraft?
Two General Electric CF-34-8E5 Hi-bypass, 2-spool, axial-flow, turbo fan
How much thrust do the CF-34-8E5 engines produce?
13,000-14,200 lbs. (ISA)
Describe N1 Spool
Single stage fan 4-stage LP turbine
Describe N2 spool
10-stage compressor (gas generator) 2-stage HP turbine
How many igniters per engine?
2 per engine
How many igniters activate for engine start?
Flight: 2 igniters (switch in AUTO)
Ground: 1 igniters (switch in AUTO)
The FADEC energizes one igniter for on-ground engine starts and both igniters for in-flight engine starts
What happens when the ignition switch is selected to OVRD?
Activates both igniters on the ground or in flight
Can the igniters be turned off in flight?
The switch may be moved to the OFF position but the FADEC disregards the command
The OFF position is used for dry motoring on the ground only
What controls the engine?
A two-channel FADEC
One channel is active and the other channel remains in the standby as backup
Is only one FADEC channel used every flight?
No.
They automatically alternate with each engine start
What does the cyan line on the N1 gauge represent during approach?
When does it appear?
The minimum N1 for bleed requirements in icing conditions.
Configured for landing less than 1200 feet RA (when anti-ice is on)
What sources are available for engine starting?
APU
Ground source (huffer cart or air bottle)
Opposite engine (Cross bleed start)
Windmill start
Does the FADEC provide engine start protection?
Only on the ground for a hot start, hung start or no light off.
The FADEC has NO protection for hot starts, hung starts or failure to light off for in flight starts.
**What will the FADEC automatically do in case of a hot start on the ground?
FADEC will not allow FF if ITT is greater than 120C.
FADEC will automatically dry motor engine and introduce fuel when ITT is less than 120C
Describe the engine start sequence
Start switch momentarily to START:
7% N2: Ignition
20% N2: Fuel flow
20% N2 + 5 seconds: Light-off
50% N2: Ignition off
50% N2: Starter cutout
Engine stabilizes:
N1: 27%
ITT: 460C
N2: 62%
FF: 550lbs/hr
Oil pressure: Greater than 25 PSI
What does WML mean on the engine indications?
Windmilling engine.
The FADEC has detected a flame-out and is attempting an auto re-light, or an assisted start has been conmanded
What provides underspeed and overspeed protection?
The FADEC via the FMU.
Approximately 52% N2 (underspeed) and 102% N2 (overspeed)
What happens after 3 overspeed detection events?
FADEC will not re-light the engine
What heats the fuel and cools the engine oil?
Fuel/Oil heat exchanger
What is ATTCS? What controls it?
Automatic Takeoff Thrust Control System.
Provides max thrust reserve (RSV) according to current rate previously selected via the MCDU.
FADEC controlled.
What will trigger an ATTCS event?
N1 difference greater than 15% between engines.
Engine failure during TOGA.
Windshear detected.
When is thrust reverse available?
Weight-on-wheels (ground use only)
What happens if a thrust reverser inadvertently deploys?
FADEC limits respective engine thrust to IDLE
What engine thrust rating(s) may only be used for 10 minutes?
TO-1
TO-1 RSV (TL beyond TOGA)
GA (Two engine go-around)
GA-RSV (one engine go-around or windshear)
What is FLEX?
Reduced takeoff thrust based on actual Takeoff weight.
The assumed temperature is used to set FLEX.
(telling the FADEC that it is warmer than it actually is so it will reduce thrust)
Can the FLEX thrust be reduced lower than CLB thrust?
No.
The minimum FLEX takeoff thrust is limited to 75% maximum rated takeoff thrust or CLB-2 + 0.5% N1, whichever is higher.
