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?
Ground: 1 igniter (switch in AUTO)
Flight: 2 igniters (switch in AUTO)
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 during 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 standby as a 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 < 1200’ RA (when anti-ice is ‘ON’)
What sources are available for engine starting?
APU
Ground source (huffer cart or air bottle)
Opposite engine (crossbleed start)
Windmill start
Does the FADEC provide engine start protection?
Only on the ground for a hot start, hung start or no light-off
What will the FADEC automatically do in case of a start on the ground?
- FADEC will not allow FF if ITT >120°C
- FADEC will automatically dry motor engine and introduce fuel when ITT <120°C
Describe the engine start sequence
- Start switch momentarily to START:
- 7% N2 Ignition
- 20% N2 Fuel flow
- 20% N2+ 5 sec Light-off
- 50% N2 Ignition off
- 50% N2 Starter cutout
Engine stabilizes:
● N1 27%
● ITT 460°C
● N2 62%
● FF 550 lbs/hr
● Oil Pressure >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 commanded
What provides underspeed and overspeed protection?
The FADEC via the FMU
Approximately 52% N2 and 102% N2 respectively
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 Take-off 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 >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 temp is used to set FLEX (telling the FADEC that it is warmer than it actually is so it will reduce the thrust)
Can the FLEX thrust be reduced lower than CLB thrust?
No
