APU

Question 1

What is the purpose of the APU?

Answer 1

allows autonomous ground ops without the use of external services

Question 2

What are the 2 main functions of the APU?

Answer 2

1. Provides pneumatic power to the ECS sys and ATS for engine starting
2. Drives the 28V DC, 5kW generator to provide electrical power

Question 3

When will the APU auto shut-down?

Answer 3

when gear lever is moved from down to up

Question 4

What controls APU ops?

Answer 4

Electronic Control Unit (ECU)

Question 5

Where is the APU located? Intake and exhaust locations?

Answer 5

In the rear fuselage above the engines
intake is on L side, exhaust is on R side

Question 6

T/F: APU draws fuel directly from the A/C fuel supply

Answer 6

True

Question 7

T/F: APU draws oil from the A/C oil supply

Answer 7

False, it has its own self contained oil system

Question 8

L/R ATS LIMIT caution

Answer 8

ATS speed > 12500rpm

Question 9

L/R ATS OVSPD caution

Answer 9

ATS speed > 9500rpm and has not stopped OR speed signal failed

Question 10

L/R ATS VALVE caution

Answer 10

control valve open on the ground

Question 11

APU caution

Answer 11

APU inop

Question 12

APU FUEL caution

Answer 12

APU fuel sys inop

Question 13

APU GEN caution

Answer 13

APU GEN inop or disconnected