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24 Cards in this Set
- Front
- Back
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What monitors and controls the APU
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FADEC
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What happens when you push in the APU emergency stop button
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Fuel shut off valve will close
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What would you expect to see in the EMER STOP button in the event of an APU fire
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A red stripe
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Where would you find the APU RPM indication
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EICAS
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Where would you find the APU EGT indication
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EICAS
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During APU start where does the fuel come from and what pump gets it to the APU
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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
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What pump provides fuel to the APU when the engine is not running
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DC pump for start. When AC electrical is available the RT AC pump. If engines are available the RT Primary ejector pump
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What pump provides fuel to the APU when the engine is running
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RT Primary ejector pump
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If both engine bleed and APU bleed is available which one has priority
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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 |
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When is APU bleed and electrics available during an APU start
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3 seconds after 95% RPM is attained
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What battery does the APU starter use
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#2
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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 |
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What BUS provides APU fire protection
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DC ESS BUS 2-Fires bottle
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What BUS provides APU fire detection
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DC ESS BUS 1
DC ESS BUS 2 |
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What are the 3 ways to shutdown the APU
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APU EMER STOP
APU FIRE EXT button OFF Button |
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What is the normal cool down period for the APU during a normal shutdown
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1 minute
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Explain the APU start process
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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 |
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When is an APU auto shutdown commanded on the ground
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APU OVERSPEED
APU UNDERSPEED APU FIRE APU EGT OVER TEMP APU HIGH OIL TEMP APU LOW OIL PRESSURE FADEC CRITICAL FAULT SENSOR FAIL |
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When is an APU auto shutdown commanded in the air
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APU OVERSPEED
APU UNDERSPEED APU FADEC CRITICAL FAULT |
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What type of power does the APU need to start
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DC
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How does the APU oil system differ from the IDG's
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The APU and APU gen share the same oil system
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After an APU fire is detected and the red bar lights up in the is EMR STOP, what happens after it is pushed
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A white bar will go on in the EMER STOP and the APU FIRE EXT will light up red
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The APU fire detection system is comprised of how many fire detectors
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Two pneumatic detectors in two loops
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What happens if an apu fire is detected and no response is given to the emergency stop
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After one minute the APU FIRE EXT button will illuminate red
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