APU Flashcards
How many seconds must you wait between attempted APU starts?
15.
During a Wing/APU fire on the ground, you have a verified fire with the firegaurd, your next step would be to?
Execute Emergency Shutdown.
If the APU system SBIT indicates a FAULT what will you see on the MFD WRA TEST Status Page?
F(S) in the stat column next to the failed component.
Electrical operating power for the APU engine system consists of __________.
28 Volts Direct Current (VDC)
What are the five EMERGENCY SHUTDOWN steps?
Verify, APU, Battery, Egress, Ground Control.
The components driven by the MWGB during APU operation are?
No. 3 Hydraulic Pump/Oil Cooler Blower/Shaft Driven Compressor
__________ shall not be selected for normal operations. Damage to aircraft may occur.
Emergency Run/Engage
APU is limited to ground operations.
TRUE.
During APU crank mode a time-out feature limits this operation to __________ seconds maximum.
30
The APU can only be started with external power on.
FALSE.
The APU system interfaces with the drives the MWGB to provide electrical, hydraulic, and pneumatic power for…
TRUE.
Automatic shutdown protection is not provided for which of the following?
Low fuel pressure.
Prior to APU start, the WFPS shall be DISABLED if any panels are removed from the wing/midwing.
TRUE.
Fuel is supplied to the APU by the __________.
RH Feed Tank
If the APU fails to start after 3 attempts, APU Start motor shall be allowed to cool for __________ minutes before attempted.
55
The APU control panel is labled Run/Engage, Run/Disengage, Emergency Run/Engage, Crank, and
STOP.
A maintenance/VSLED download is required after every APU run.
FALSE.
The #3 Hydraulic system pressure should read between __________.
4600-5250
If the WFPS is DISABLED no wing fire detection/protection is available.
TRUE.
When the APU is started, which generator(s) is on line?
CFG #1.
WFPS control switch is located on wihich PDP?
PDP 3.
The first step of the APU checklist is __________.
Aircraft safe for maintenance.
During Run/Disengage mode the APU will perform the same function as the Run/Engage except the __________.
Clutch
At what temperature must the APU clutch be preheated for 15-30 minutes?
-25 Degrees F and below.
Which of the following is NOT checked for servicing at the GRDP?
CFG.
When operating the APU in the CRANK mode, how long will the APU motor?
30 seconds.
The APU engage ASI will show up on the __________.
CDU
What is the minimum battery voltage required for APU start?
23.5 Volts.
The first step in the Wing/APU fire on the ground checklist is
Verify APU fire with firegaurd.
To prevent inadvertent actuation, the NAC CONT DSBL switches shall be selected to DSBL anytime nacelles are…
TRUE.
The APU ignition is initiated with two ignitors which receive __________ volts from the ignition exciter.
5000
Once the APU has started, the fuel system will maintain what constant turbine speed?
98-102%.
The APU start motor will disengage at __________ percent of the APU self-sustaining speed of 100%.
50
In the event of a Wing/APU fire on the ground, the last step is to?
Alert Ground Control.
