Engine Flashcards
What type of Engine do we have?
General Electric CF34-8E5
High-Bypass, 2 spool, axial-flow, turbo-fan
2 spools = N1(4 stages) and N2 (10 stages) section
How much thrust does teh CF-34-8E5 engines product?
13,000 lbs
14,200 lbs with ATTCS
How is the engine controlled?
Dual channel FADEC system
What does WML by N2 mean?
A WML icon is displayed whenever the FADEC has detected an engine flameout and the auto re-light system is actuating to restart the engine.
an assisted start has been commanded
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.
igniters 1B and 2B are connected to SPDA 2 - in case of SPDA 2 failure, setting the selector knob to OVRD energizes at least igniter A.
Can the igniters be turned off during flight?
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 is the purpose of the lubrication system?
lubricates and cools the turbine engine main shaft bearings and the accessory gearbox and the engine
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 cart unit. Same same)
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. no protection in flight.
what does the engine starting system consist of?
Air Turbine Starter (ATS)
Starter Control Valve (SCV)
what does the pneumatic system provide here?
bleed air to the ATS to rotate the rotor speed and start the engine
what will the FADEC automatically do in case of a start on the ground?
FADEC will not allow fuel flow if ITT > 120 degrees 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 seconds light off
50% N2 ignition off
50% N2 starter cutout
When is the engine stabilized?
N1 27%
ITT 460 Degrees C
N2 62%
FF 550 lbs/hr
Oil pressure > 25 PSI
What provides underspeed and overspeed protection?
the FADEC via the Fuel Metering Unit (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 - available for takeoff and go around (automatically armed when thrust rate mode is GA)
what will trigger an ATTCS events?
N1 difference > 15% between engines
Engine failure during TOGA
Engine failure during go around
windshear detected
When are thrust reversers available?
Weight-on-wheels
