APU

Question 1

T/F: The APU can be used during flight.

Answer 1

FALSE, Ground Only operation

Question 2

T/F: The APU can only be used on the ground.

Answer 2

TRUE

Question 3

On which side of the fuselage is the APU air intake located?

Answer 3

Right rear side of the tailcone

Question 4

Which of the following combinations causes the highest fuel burn while operating the APU?

Answer 4

Highest fuel burn is Generator ON and Bleed Air ON (270 lbs/hr)

Question 5

When will the fuel shut off valve automatically close on the APU?

Answer 5

PWR switchlight pushed OFF
Airplane airborne
Fire detected in tailcone
EXTG (Extinguish) pushlight is pushed
APU fire test button is pushed
Starter-Generator overheats
APU fault is detected

Question 6

The APU is started with _____.

Answer 6

Main & Aux batteries
or
External power

Question 7

Pressing the PWR switchlight on the APU control panel, in preparation for APU start, does which of the following?

Answer 7

Opens APU fuel shut off valve
Arms start circuits
Performs a brief self-test

Question 8

T/F: The APU cannot be used as a source of bleed air on the ground.

Answer 8

FALSE, it can be used as a bleed air source

Question 9

T/F: APU bleed air can operate in conjunction with engine bleed air.

Answer 9

FALSE, it cannot be used in conjunction

Question 10

T/F: APU bleed air cannot operate in conjunction with engine bleed air.

Answer 10

TRUE

Question 11

T/F: The APU can be used while the aircraft is airborne.

Answer 11

FALSE, the APU is limited to ground operations only

Question 12

T/F: The APU can be used on the ground for electrical, pneumatic, and hydraulic power.

Answer 12

FALSE, the APU does not provide hydraulic power

Question 13

When ready to start the APU, what should be accomplished after pressing the PWR switchlight?

Answer 13

Verify green APU fuel valve open advisory light illuminates

Question 14

The green ON light illuminates on the APU GEN switchlight when the APU is running at full speed and can supply which of the following?

Answer 14

28VDC power

Question 15

Where can the APU’s electrical load be monitored?

Answer 15

MFD electrical page

Question 16

T/F: Once the APU is at normal operating speed, APU bleed air is automatically supplied with no pilot input.

Answer 16

FALSE, the APU BL AIR switchlight must be pressed and “OPEN” illuminated

Question 17

What color is the light that illuminates when the APU Fuel valve is OPEN?

Answer 17

Green advisory light on APU fire protection panel

Question 18

T/F: If the APU generator overheats, the APU will automatically shut down.

Answer 18

TRUE

Question 19

What will happen if an APU generator fault is detected?

Answer 19

Generator disconnected from DC electrical system,
ON light extinguishes from switchlight,
GEN WARN advisory light illuminates on switchlight

Question 20

Fuel for the APU operation is supplied from which fuel tank?

Answer 20

Left wing collector bay

Question 21

What does the APU GEN WARN light indicate?

Answer 21

Any of the following:
Generator has not been selected with the APU running
Generator is selected on but does not come on-line
Generator is taken off line due to a malfunction