APU Operation & Emergency Procedures

Question 1

An APU fire is indicated by what?

5 indicators

Answer 1

• MASTER WARNING lights on INSTRUMENT panel
• APU displayed on CUE
• LOOP A and LOOP B lights on ENVIR panel
• Central Aural Warning System and APU warning horns
• FIRE light on APU panel

Question 2

What is the APU fuel consumption rate?

Answer 2

500 lbs/hr

Question 3

What kind of power may be used to start APU’s when external power is not available?

Answer 3

Battery power

Question 4

What should be done if the APU fails to spool up during battery start?

Answer 4

Reset APU START circuit breakers

Question 5

APU operation shall not be accomplished without ____ ____________, and the ability to contact whom?

Answer 5

Radio communication; the fire department

Question 6

The APU will not be operated with what system inoperative?

Answer 6

Fire detection system, loops A&B

Question 7

Under what condition is the aircraft mounted fire extinguishing system not sufficient to to extinguish a fire?

Answer 7

When the APU access doors are open

Question 8

What accommodations are needed when APU must be operated with the access doors open?

Answer 8

Standby assistance from a ground/fire observer equipped with a 150 lb. fire bottle

Question 9

What should be done if a MANIFOLD FAIL light appears on the ENVIR panel, or a “Manifold Fail” Aural Warning sounds anytime during APU operation?
(3 steps)

Answer 9

• ## Immediately press the APU switchlight on the ENVIR panel to extinguish the flow line

Question 10

Flaps/Slats shall be in what position during APU operation?

Answer 10

Full up

Question 11

APU may be started with the flaps/slats down; however, they shall be set to the full up position within how many seconds after APU stabilization?

Answer 11

30 seconds

Question 12

The APU will only be shut down using the AGENT/OFF ARM switches at any location, under what condition?

Answer 12

In the case of actual or perceived emergency

Question 13

The APU shall not be operated when the number __ engine left fan thrust reverser duct is open, and he ambient air temperature is ABOVE __°C (__°F).

Answer 13

3; 32; 90

Question 14

The APU may be operated for __ minutes with the #3 engine left fan thrust reverser duct open and the ambient air temperature is BELOW 32°C (90°F)

Answer 14

15

Question 15

When APU does not start on first attempt with winds above 35 knots, what do you do before attempting another start?
(2 methods)

Answer 15

• Reposition aircraft to keep APU exhaust from being ingested into the inlet
• Wait for winds to decrease below 30 knots

Question 16

True or False:

External air leakage from the APU heat shield area is allowable.

Answer 16

True

Question 17

Why must external electrical power be used instead of APU power to run the Automatic Flight Control System (AFCS)

Answer 17

When using APU power, the weight on wheels simulation causes the APU to shutoff and all the AFCS control panel tests cannot be completed.

Question 18

When aircraft fuel is low, what may be required prior to APU start?

Answer 18

A fuel boost pump