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Flashcards in APU Deck (21)
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1
Q

The APU EGT indicator remains powered for ____ minutes after shutdown to provide display of residual EPU EGT.

A

5 minutes

2
Q

APU: amber OVERSPEED light?

A

APU RPM has been exceeded and APU has shut down automatically.

3
Q

APU: amber FAULT light?

A

auto shut down due to malfunction.

4
Q

APU: amber LOW OIL PRESSURE light?

A

normal during APU start. If on after start, APU will shut down automatically.

5
Q

Blue APU MAINT light?

A

mx issue with APU but can still be operated.

6
Q

APU ECU provides protection for what?

A
Overspeed
Low oil pressure
High oil temp
APU fire
fuel control unit failure
EGT exceedance
Other system faults
7
Q

T/F: Depending on ambient conditions, the ECU will auto shed bleed air and/or electrical loads to maintain APU speed and EGT margins.

A

true.

8
Q

During engine start, which gets shed first, elec or bleed air?

A

elec first then bleed air.

9
Q

Other than engine start, which gets shed first, elec or bleed air?

A

bleed air then elec

10
Q

In flight if APU is only source of elec power, which buses are auto shed?

A

GALLEY and MAIN BUSSES. Both IFE busses will shed if elec load is still too high.

11
Q

T/F: On the ground, the APU will always attempt to carry a full load.

A

True

12
Q

The APU will normally draw fuel from the _____side of the fuel manifold provided AC fuel pumps are operating.

A

Left side

13
Q

If fuel pumps not operating, the APU will ______feed.

A

suction.

14
Q

What is the routing for the APU cooling air?

A

circulates through the APU compartment, passes through oil cooler and then discharges.

15
Q

The APU won’t operate unless:

A
  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
16
Q

Normal APU starts get AC power from which bus?

A

AC TRANSFER BUS 1

17
Q

Blue APU GEN OFF BUS means what?

A

APU is ready to accept a bleed or electric load. Also shows when APU start cycle is completed.

18
Q

The APU start cycle can take as long as _______.

A

120 seconds

19
Q

Operate the APU for _______ prior to selecting a bleed source

A

1 full minute

20
Q

T/F: Run the APU for 1 full minute without a bleed air source before shutting down.

A

True.

21
Q

T/F: The APU auto shuts down 60 seconds after positioning the switch to OFF.

A

True