APU

Question 1

The APU provides ____.

a. electrical power
b. pneumatic air
c. both electrical power and pneumatic air
d. preconditioned air

Answer 1

C. both electrical power and pneumatic air

Question 2

The APU start cycle may take as long as ____.

a. 120 seconds
b. 25 seconds
c. 60 seconds
d. 180 seconds

Answer 2

A. 120 seconds

Question 3

With the APU operating, turning OFF the battery switch will cause the APU to ____.

a. continue running without supplying electrical power or bleed air
b. unload the APU generator
c. begin a 60 second cool down period
d. shutdown immediately

Answer 3

D. shutdown immediately

Question 4

Fire protection for the APU is provided by ____ fire extinguishing bottle(s)

a. 1
b. 2
c. 3
d. 4

Answer 4

A. 1

Question 5

The APU fire extinguishing agent discharges ____.

a. either automatically or manually
b. manually only
c. automatically only
d. both automatically and manually

Answer 5

B. manually only

Question 6

The APU can be started with electrical power from ____.

a. AC Emergency Bus or the airplane battery
b. TR Bus 1 and the AC Emergency Transfer Bus
c. AC Transfer Bus 1 or the airplane battery
d. its own internal battery

Answer 6

C. AC Transfer Bus 1 or the airplane battery

Question 7

With the APU blue MAINT light illuminated, the crew ____.

a. should move the start switch to OFF momentarily
b. should restart the APU after the auto shutdown
c. pull the APU fire handle
d. may continue to use the APU if needed

Answer 7

D. may continue to use the APU if needed

Question 8

The APU EGT is displayed on the ____.

a. not displayed
b. lower MFD screen
c. forward overhead panel
d. upper MFD screen

Answer 8

C. forward overhead panel

Question 9

In order to start the APU on a cold, dark airplane, the ____.

a. Battery switch must be ON and the cockpit APU fire handle must be IN. The ground control panel fire handle may be PULLED
b. battery switch must be ON, the cockpit APU fire handle must be IN, and the ground control panel fire handle must be IN
c. Battery switch must be OFF. The cockpit APU fire handle and the ground control panel fire handle may be IN or PULLED
d. Ground Service Bus must be powered by an external power source

Answer 9

B. battery switch must be ON, the cockpit APU fire handle must be IN, and the ground control panel fire handle must be IN

Question 10

The APU can be started at altitudes up to ____ feet

a. 17,000
b. 41,000
c. 10,000
d. 25,000

Answer 10

B. 41,000

Question 11

The APU Start Switch has ____ positions labeled.

a. OFF and ON
b. OFF, RUN, and START
c. OFF, ON, and START
d. OFF, ON and RUN

Answer 11

C. OFF, ON, and START

Question 12

An automatic APU shutdown will occur for ____.

a. overspeed, fire, high oil pressure
b. low oil pressure, fault, overspeed
c. fault, overheat, low oil quantity
d. fire, high oil pressure, fault

Answer 12

B. low oil pressure, fault, overspeed

Question 13

Which of the following will cause the APU to shut down?

a. Overspeed
b. High oil temperature
c. Fault
d. All of the above

Answer 13

D. All of the above

a. Overspeed
b. High oil temperature
c. Fault
d. All of the above

Question 14

The maximum altitude for use of APU bleed air and electrical power is _____ feet.

a. 17,000
b. 25,000
c. 10,000
d. 14,000

Answer 14

C. 10,000

Question 15

The maximum altitude for use of APU bleed air only is _____ feet.

a. 25,000
b. 14,000
c. 10,000
d. 17,000

Answer 15

D. 17,000

Question 16

If airborne and the battery is the only available power source, APU start attempts are not recommended above ____ feet.

a. 25,000
b. 17,000
c. 10,000
d. 32,000

Answer 16

A. 25,000

Question 17

On the ground, the APU ____.

a. attempts to carry a partial electrical load
b. cannot shed the galley
c. will power both transfer busses
d. will not power the main busses

Answer 17

C. will power both transfer busses

Question 18

You observe these lights on after starting the APU, and they were not on prior to start. Which statement is the most correct?

a. The APU failed a self-check overspeed test and should not be used.
b. The APU had an overspeed fault and shut down automatically.
c. The APU overspeed light comes on during start and should extinguish shortly, indicating a good test.
d. You should shut down the APU for five minutes, and then attempt a second start.

Answer 18

B. The APU had an overspeed fault and shut down automatically.

Question 19

If this light came on shortly after placing the APU start switch to on, __.

a. this is normal and the light will extinguish after the APU cooling time has commenced
b. this indicates the APU has overspeed and shut down
c. the overspeed shutdown protection feature has failed a self-test during a normal APU shutdown
d. this light informs the crew that overspeed protection is lost and the APU may be used if they monitor the EGT and Frequency meter

Answer 19

C. the overspeed shutdown protection feature has failed a self-test during a normal APU shutdown

Question 20

After shutting off the APU that has an illuminated Overspeed light, the light will __.

a. extinguish immediately
b. remain on for five minutes and then extinguish
c. not extinguish until maintenance resets the system
d. blink to indicate that the system needs to be reset

Answer 20

B. remain on for five minutes and then extinguish

Question 21

After 3 consecutive aborted start attempts on the APU, how long of a cooling period must be observed?

a. 15 mins
b. 10 mins
c. 3 mins
d. No limitations

Answer 21

A. 15 mins

Question 22

(MAX) The blue MAINT light:

a. DOOR light has replaced the MAINT light on the control panel.
b. Has not changed in function.
c. Monitors APU door only.
d. Now monitors Exhaust Gas Temperature since the gauge has been removed.

Answer 22

A. DOOR light has replaced the MAINT light on the control panel.