APU Certification Written Test Guide Flashcards
What is the minimum amount of fuel required to operate the APU and from which tank?
1000lbs in the left tank
You must push and hold the FIRE/OVHT TEST switch for approximately __ seconds
7
What is the outside observer looking for during APU start-up with access door open?
Fire
Releasing the APU control switch from the START position to the ON position can cause damage to what?
Internal parts of the Switch
What is the start duty cycle for the APU?
3 starts in 60 minutes
You must hold the APU control switch to the START position for approximately __ seconds before manually moving the switch to the ON position.
1
Approximately how many seconds does the APU continue to operate during its cool-down cycle?
100
What position must the BAT switch be in until after the APU cool-down cycle and the APU engine stops its operations?
ON
What secondary panel can you operate the APU from and where is it located?
P40 Panel on the Nose Landing Gear
Max EGT will be what degrees when APU Operation-No Bleed Air is on?
716
Max EGT will be what degrees when APU Operation Pressure Mode-Duct?
663
If the APU has not been operated for over a month, operate the APU for a minimum of minutes under a No-Load condition.
5
What happens when the Main Battery Bus is ON and there is NO AC power?
Warning Horn
When APU speeds reach 95 percent what light comes on?
RUN Light
The APU can be restarted once the APU speed is below _ percent.
7
If there is refuel operations in the area during APU start/operation, you must obey with Warnings, Cautions, and Notes for the Pressure Refuel?
True
The APU starter motor disengages from the starter clutch at these conditions?
APU speed is 50 percent and the starter motor is energized for 90 seconds
The Air-Intake Door actuates open in less than how many seconds?
115
Shut-down the APU if what light comes on and fuel quantity is under limits?
Low Pressure Light
If you are operating the APU with more than 1000lbs of fuel, what is the standard procedure?
Permitted to NOT have an observer as long as you calculate the time to get back to the flight compartment when the fuel reaches below these limits.
If the quantity of fuel is below the minimum limits for normal APU operation and the fuel boost pumps must be operated, what must be done?
A maintenance person or observer is in the flight compartment to continuously monitor the LOW PRESSURE lights and fuel quantity indicator
Observer should be in ______ contact with aircraft personnel when starting APU with doors open.
Aural
How many times will the RUN LIGHT flash when the APU electronic control unit completes its APU BITE power-up test?
Once
Before applying pneumatic load, bleed duct pressure must be more than 50 psig on the DUCT PRESS indicator
False. Pressure must be more than 20 psig.
During shutdown the Air-Intake Door and APU Fuel Shutoff Valve must close in approx.______?
60 seconds
Emergency Procedures Inside Aircraft
- Push the manual override and pull APU fire switch
(Note: Handle located on AFT Electronics Control Panel) - If there is a fire turn the handle
- Make sure APU immediately stops operation
Emergency Procedures Outside Aircraft
- Push APU FIRE SHUTDOWN on P40 Panel
-Make sure amber APU BOTTLE ARMED light comes on
-If fire press APU BOTTLE DISCHARGE SWITCH and APU Stop switch together
-Make sure APU immediately stops operation
How many magnetic chip detectors does the APU have?
4
