Term
| APU operation requires the following: |
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Definition
APU fire switch on the overheat/fire panel must be IN
APU fire control handle on the APU ground control panel must be IN
Battery switch must be ON |
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Term
| The APU Electronics Control Unit (ECU) provides: |
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Definition
Automatic shutdown protection for overspeed conditions, low oil pressure and high oil temperature
Automatic shutdown protection for APU fire, fuel control unit failure and EGT exceedance
Automatic control of APU speed through the electronic fuel unit |
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Term
| The APU can supply both transfer busses: |
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Definition
| On the ground or in the air |
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Term
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Definition
| Enters through a cooling air inlet above the APU exhaust outlet |
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Term
True/False
During APU operation, fuel is automatically heated to prevent icing: |
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Definition
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Term
| Moving the battery switch to OFF automatically shuts down the APU. |
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Definition
On the ground or in the air
Because of power loss to the Electronic Control Unit (ECU) |
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Term
| The APU generator ammeter: |
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Definition
| Is displayed in a digital readout format on the electrical panel |
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Term
| It is recommennded to operate the APU for _____ before using it as a bleed air source. |
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Definition
1 full minute
This one minute stabilization is recommended to extend the service life of the APU |
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Term
True/False
During the APU start cycle, the APU EGT indication may fluctuate from 0º to 1100º C prior to normal EGT rise and the LOW OIL PRESSURE light may cycle on and off several times. These indications have no adverse effect on starting the APU. It is not necessary to monitor EGT during start. |
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Definition
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Term
| Electrical power to start the APU comes from: |
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Definition
The No.1 Transfer bus if available. If AC power is not available, battery power is used
With no AC power, the starter generator uses battery power to start the APU |
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Term
| If the APU is the only source of electrical power: |
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Definition
| In flight, the galley busses are automatically shed |
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Term
| The APU switch OFF position has an automatic shutdown delay of: |
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Definition
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Term
| The APU is capable of supplying bleed air for both air conditioning packs: |
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Definition
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Term
| The APU may be used as an electrical and pneumatic source simultaneously up to: |
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Definition
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Term
| The APU start cycle may take up to: |
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Definition
120 seconds
Automatic shutdown occurs in the event of EGT exceedance |
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Term
| The APU may be used as a pneumatic source up to: |
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Definition
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Term
| The APU will shutdown on the ground if: |
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Definition
| The battery switch is placed to OFF |
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Term
True/False
When the APU is started using battery power only, there is a normal indication on the electrical metering panel that the APU generator has come on line and is ready to be selected. |
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Definition
False
When the APU is started using battery power only, there is a NO indication on the electrical metering panel that the APU generator has come on line and is ready to be selected. Both the frequency and voltage readings are zero until the APU generator is placed on line |
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Term
| If the APU GEN OFF BUS light fails to illuminate by the end of the start cycle: |
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Definition
| The FAULT light illuminates |
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Term
| True/False In flight, if the APU is the only source of electrical power, all galley busses are automatically shed. If electrical load still exceeds design limits, both main busses automatically shed until the load is within design limits. On the ground, the APU attempts to carry a full electrical load. If an overload condition is sensed, the APU sheds galley busses first, and then both main busses until the load is within limits. |
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Definition
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Term
| The APU OVERSPEED light illuminated indicates: |
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Definition
APU RPM limit has been exceeded resulting in an automatic shutdown
The overspeed shutdown protection feature has failed a self-test during a normal APU shutdown
If light is illuminated when APU switch is placed to OFF, light extinguishes after 5 minutes (light is disarmed when the APU switch is in OFF position). |
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Term
| Of the four lights located on the APU control panel, which light will NOT cause an automatic shutdown of the APU when it illuminates? |
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Definition
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Term
| The APU starts, operates and can supply electrical power alone up to: |
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Definition
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Term
| The blue APU MAINT light means that: |
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Definition
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Term
| Pulling up the APU fire warning switch: |
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Definition
| Trips the generator control relay and breaker, arms the associated extinguisher and closes the bleed air valve, closes the fuel shutoff valve, and the APU inlet door |
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Term
True/False
When the APU is started using battery power only, there is no indication on the electrical metering panel that the APU generator has come on line and is ready to be selected. Both the frequency and voltage readings are zero until the APU generator is placed on line. |
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Definition
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