Flashcards in APU Deck (21)
The APU EGT indicator remains powered for ____ minutes after shutdown to provide display of residual EPU EGT.
APU: amber OVERSPEED light?
APU RPM has been exceeded and APU has shut down automatically.
APU: amber FAULT light?
auto shut down due to malfunction.
APU: amber LOW OIL PRESSURE light?
normal during APU start. If on after start, APU will shut down automatically.
Blue APU MAINT light?
mx issue with APU but can still be operated.
APU ECU provides protection for what?
Low oil pressure
High oil temp
fuel control unit failure
Other system faults
T/F: Depending on ambient conditions, the ECU will auto shed bleed air and/or electrical loads to maintain APU speed and EGT margins.
During engine start, which gets shed first, elec or bleed air?
elec first then bleed air.
Other than engine start, which gets shed first, elec or bleed air?
bleed air then elec
In flight if APU is only source of elec power, which buses are auto shed?
GALLEY and MAIN BUSSES. Both IFE busses will shed if elec load is still too high.
T/F: On the ground, the APU will always attempt to carry a full load.
The APU will normally draw fuel from the _____side of the fuel manifold provided AC fuel pumps are operating.
If fuel pumps not operating, the APU will ______feed.
What is the routing for the APU cooling air?
circulates through the APU compartment, passes through oil cooler and then discharges.
The APU won't operate unless:
1. APU fire handle is in
2. APU gnd control panel in
3. APU fire switch on overheat/fire panel-in
4. BAT switch -on
Normal APU starts get AC power from which bus?
AC TRANSFER BUS 1
Blue APU GEN OFF BUS means what?
APU is ready to accept a bleed or electric load. Also shows when APU start cycle is completed.
The APU start cycle can take as long as _______.
Operate the APU for _______ prior to selecting a bleed source
1 full minute
T/F: Run the APU for 1 full minute without a bleed air source before shutting down.