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24 Cards in this Set

  • Front
  • Back
What monitors and controls the APU
FADEC
What happens when you push in the APU emergency stop button
Fuel shut off valve will close
What would you expect to see in the EMER STOP button in the event of an APU fire
A red stripe
Where would you find the APU RPM indication
EICAS
Where would you find the APU EGT indication
EICAS
During APU start where does the fuel come from and what pump gets it to the APU
Comes from the RT tank and is provided by the primary ejector pump if the engines are running, ac pump if electrical power is there or DC pump if none of the above is available
What pump provides fuel to the APU when the engine is not running
DC pump for start. When AC electrical is available the RT AC pump. If engines are available the RT Primary ejector pump
What pump provides fuel to the APU when the engine is running
RT Primary ejector pump
If both engine bleed and APU bleed is available which one has priority
When the following conditions are met the APU will receive priority:
1.Airplane on ground
2.Opposite engine bleed pressure is below the minimum for engine start
3.Ground speed below 50 knts
4.X bleed valve operating normally
When is APU bleed and electrics available during an APU start
3 seconds after 95% RPM is attained
What battery does the APU starter use
#2
Describe the APU start sequence during the following
Ground start
In-flight start
Ground:
1.Ignition @6%
2.fuel flow 5 sec. later
3. Batt 2 energizes the electronic starter controller
4.Light off occurs
5.FADEC commands starter cut out at 50% RPM

In-Flight:
1.Ignition @7-17%
2.Fuel flow .25 seconds later
3.Light off
4.FADEC commands starter cut out at 50% RPM
What BUS provides APU fire protection
DC ESS BUS 2-Fires bottle
What BUS provides APU fire detection
DC ESS BUS 1
DC ESS BUS 2
What are the 3 ways to shutdown the APU
APU EMER STOP
APU FIRE EXT button
OFF Button
What is the normal cool down period for the APU during a normal shutdown
1 minute
Explain the APU start process
1.FADEC energizes start controller at 7% rpm
2.FADEC commands fuel module to open and energize the exciter
3.At 50% rpm the ignition exciter and starter are deenergized and the APU runs on its own. 3 seconds after 95% rpm is achieved the APU is ready for electrics and pneumatics
When is an APU auto shutdown commanded on the ground
APU OVERSPEED
APU UNDERSPEED
APU FIRE
APU EGT OVER TEMP
APU HIGH OIL TEMP
APU LOW OIL PRESSURE
FADEC CRITICAL FAULT
SENSOR FAIL
When is an APU auto shutdown commanded in the air
APU OVERSPEED
APU UNDERSPEED
APU FADEC CRITICAL FAULT
What type of power does the APU need to start
DC
How does the APU oil system differ from the IDG's
The APU and APU gen share the same oil system
After an APU fire is detected and the red bar lights up in the is EMR STOP, what happens after it is pushed
A white bar will go on in the EMER STOP and the APU FIRE EXT will light up red
The APU fire detection system is comprised of how many fire detectors
Two pneumatic detectors in two loops
What happens if an apu fire is detected and no response is given to the emergency stop
After one minute the APU FIRE EXT button will illuminate red