APU

Question 1

Q1: What systems are supported by the APU?

Answer 1

A: It provides an alternate source of AC electrical power and bleed air for main engine starting and air conditioning.

Question 2

Q2: Where are the APU indications displayed?

Answer 2

A: On the STATUS, AIR, ELEC, and FUEL synoptic pages.

Question 3

Q3: What happens if an APU BITE test fails?

Answer 3

A: The FAIL light on the APU panel illuminates and an APU FAULT advisory message is displayed on the EICAS page.

Question 4

Q4: How is the APU inlet door controlled?

Answer 4

A: By the APU ECU.

Question 5

Q5: What is the power output of the APU generator?

Answer 5

A: 115 VA

Question 6

Q6: At what percent RPM is the APU ready for electrical and pneumatic loading?

Answer 6

A:95%

Question 7

Q7: How many APU starts may be attempted in one hour?

Answer 7

A:3

Question 8

Q8: What happens when the APU switch is selected OFF: A- under load? B-When not under load?

Answer 8

A: The ECU starts a 60 second cool down period then shuts down.
B: The ECU immediately shuts down the APU

Question 9

Q9: When the 60 second APU cool down period has finished, what happens?

Answer 9

A: The ECU shuts down the APU and closes the inlet door

Question 10

Q10: Will an APU FIRE in flight cause the APU to automatically shut down?

Answer 10

A: No.

Question 11

Q11: What two external APU shutoff switches allow the APU to be shut off from the outside?

Answer 11

A: The guarded APU SHUTOFF switch on the external service panel & The shutdown switch located in the APU compartment