Study Guide Engines Flashcards
How much thrust?
13,800to 14,200
Describe n1 spool
Single stage fan… Four stage low pressure turbine
Describe the N2 spool
Ten stage compressor……Gas generator.
Two stage high pressure turbine
How many igniters per engine?
Two
How many igniters activate for engine start?
One on ground and two for in flight.
What happens when engine switch is set to override?
Both igniters commanded on either in flight or on ground.
Can the igniters be turned off during flight?
The switch may be turned to the OFF position during flight but the FADEC disregards the command.
The OFF position is used for dry motoring on the ground.
What controls the engine?
A two channel FADEC.
What does the cyan line on the N1 gauge represent during an approach and when does it appear?
The min N1 for anti icing conditions. It comes on when configured for landing when below 1200 radar altimeter, configured for landing and when anti ice is on.
What sources of air are avail for engine start?
APU
Cross bleed air
Ground cart
Windmilling
Does FADEC provide engine start protection?
Only on the ground for hot and hung starts or no light off.
What will the FADEC automatically do in case of a start on the ground?
Will not allow fuel flow with ITT above 120 C
FADEC will auto dry motor the engine and introduce fuel at ITT less than 120.
Describe the engine start sequence.
Switch monetarily to start. At 7% N2 ignition At 20% N2 fuel flow..... Provided temp is below 120 At 20% N2 plus five seconds, light off At 50% N2, starter ignition off.
Engine stabilizes at about what settings?
N1.....27 ITT 460 N2... 62 Fuel flow..... 550 pounds per hour Oil pressure.... 25 psi
Thrust ratings
Take off 1, take off 1 reserve, go around and go around reserve is ten minutes.
CON is continuous max thrust… CLB (Max climb thrust) CRZ is max cruise…. Idle
What does WML mean on engine indications?
Windmilling engine
FADEC is attempting a relight of a flamed out engine or an assisted start has been commanded.
What provides under and over speed protection?
The FADEC via the FMU…. fuel metering unit.
This happens at about 52 N2 and 102 N2
What happens after three over speed detection events?
FADEC will not relight the engine.
What heats the fuel and cools the oil?
The fuel..oil heat exchanger.
What is ATTCS and what controls it?
Automatic take off thrust control system.
It provides max thrust reserve according to the current rate previously selected via the MCDU and is FADEC controlled.
What will trigger an ATTCS?
N1 difference of 15% between the two engines.
Engine failure during toga
Wind shear detected.
Hen is thrust reverse available?
Weight on wheels
What happens if a thrust reverse inadvertently deploys?
FADEC limits respective engine thrust to idle.
What thrust engine ratings may be used only for ten minutes?
TO-1
TO- RSV. (Levers beyond toga)
GA RSV …. One engine inop or wind shear.
What is flex?
Reduced take off power using an assumed temp.. Telling the Fms that is is hotter than it actually is.
Can flex be reduced lower than climb thrust?
No
What type of engines?
General Electric CF-34-8E5…. Hi-bypass two spool axial flow turbo fan.
