APU Certification Written Test Guide

Question 1

What is the minimum amount of fuel required to operate the APU and from which tank?

Answer 1

1000lbs in the left tank

Question 2

You must push and hold the FIRE/OVHT TEST switch for approximately __ seconds

Answer 2

7

Question 3

What is the outside observer looking for during APU start-up with access door open?

Answer 3

Fire

Question 4

Releasing the APU control switch from the START position to the ON position can cause damage to what?

Answer 4

Internal parts of the Switch

Question 5

What is the start duty cycle for the APU?

Answer 5

3 starts in 60 minutes

Question 6

You must hold the APU control switch to the START position for approximately __ seconds before manually moving the switch to the ON position.

Answer 6

1

Question 7

Approximately how many seconds does the APU continue to operate during its cool-down cycle?

Answer 7

100

Question 8

What position must the BAT switch be in until after the APU cool-down cycle and the APU engine stops its operations?

Answer 8

ON

Question 9

What secondary panel can you operate the APU from and where is it located?

Answer 9

P40 Panel on the Nose Landing Gear

Question 10

Max EGT will be what degrees when APU Operation-No Bleed Air is on?

Answer 10

716

Question 11

Max EGT will be what degrees when APU Operation Pressure Mode-Duct?

Answer 11

663

Question 12

If the APU has not been operated for over a month, operate the APU for a minimum of minutes under a No-Load condition.

Answer 12

5

Question 13

What happens when the Main Battery Bus is ON and there is NO AC power?

Answer 13

Warning Horn

Question 14

When APU speeds reach 95 percent what light comes on?

Answer 14

RUN Light

Question 15

The APU can be restarted once the APU speed is below _ percent.

Answer 15

7

Question 16

If there is refuel operations in the area during APU start/operation, you must obey with Warnings, Cautions, and Notes for the Pressure Refuel?

Answer 16

True

Question 17

The APU starter motor disengages from the starter clutch at these conditions?

Answer 17

APU speed is 50 percent and the starter motor is energized for 90 seconds

Question 18

The Air-Intake Door actuates open in less than how many seconds?

Answer 18

115

Question 19

Shut-down the APU if what light comes on and fuel quantity is under limits?

Answer 19

Low Pressure Light

Question 20

If you are operating the APU with more than 1000lbs of fuel, what is the standard procedure?

Answer 20

Permitted to NOT have an observer as long as you calculate the time to get back to the flight compartment when the fuel reaches below these limits.

Question 21

If the quantity of fuel is below the minimum limits for normal APU operation and the fuel boost pumps must be operated, what must be done?

Answer 21

A maintenance person or observer is in the flight compartment to continuously monitor the LOW PRESSURE lights and fuel quantity indicator

Question 22

Observer should be in ______ contact with aircraft personnel when starting APU with doors open.

Answer 22

Aural

Question 23

How many times will the RUN LIGHT flash when the APU electronic control unit completes its APU BITE power-up test?

Answer 23

Once

Question 24

Before applying pneumatic load, bleed duct pressure must be more than 50 psig on the DUCT PRESS indicator

Answer 24

False. Pressure must be more than 20 psig.

Question 25

During shutdown the Air-Intake Door and APU Fuel Shutoff Valve must close in approx.______?

Answer 25

60 seconds

Question 26

Emergency Procedures Inside Aircraft

Answer 26

• Push the manual override and pull APU fire switch
  (Note: Handle located on AFT Electronics Control Panel)
• If there is a fire turn the handle
• Make sure APU immediately stops operation

Question 27

Emergency Procedures Outside Aircraft

Answer 27

• Push APU FIRE SHUTDOWN on P40 Panel

-Make sure amber APU BOTTLE ARMED light comes on

-If fire press APU BOTTLE DISCHARGE SWITCH and APU Stop switch together

-Make sure APU immediately stops operation

Question 28

How many magnetic chip detectors does the APU have?

Answer 28

4