APU

Question 1

Max load on the APU generator?

Answer 1

40 KVA

Question 2

Max altitude for APU starting?

Answer 2

37,000 ft

Question 3

Max altitude for APU operation?

Answer 3

41,000 ft

Question 4

Max altitude for APU bleed air extraction?

Answer 4

25,000 ft

Question 5

Max speed with APU door open?

Answer 5

220 KIAS if APU not operating

No speed restriction when operating

Question 6

What battery voltage is required before starting the APU?

Answer 6

22 volts on both batteries

Question 7

What does the Main Battery power during APU start?

Answer 7

APU ECU

Question 8

What does the APU Battery power during APU start?

Answer 8

Cranking the 28 VDC start motor

Question 9

When the AVAIL switchlight illuminate?

Answer 9

99% rpm + 2 seconds

Question 10

The APU’s primary function is what?

Answer 10

To power the 40 KVA generator mounted on the gearbox

Question 11

What does the APU door provide air for?

Answer 11

compressor & air/oil heat exchanger

Question 12

How is the APU door actuated?

Answer 12

Electrically

Question 13

Where does the APU receive fuel from?

Answer 13

Left collector tank

Question 14

What is the electrical power source for the ECU?

The starter?

Answer 14

Battery Bus

APU Battery Direct Bus

Question 15

What is the max rpm the starter will cutout by?

Answer 15

60%

Question 16

Start Attempts (on ground)
1
2
3

Answer 16

Max Time on—-Cool Down
ECU —-30 secs
ECU —-30 secs
ECU —-1 hr

Question 17

Start Attempts (in flight)
1
2
3

Answer 17

Max Time on—-Cool Down
ECU —-1 min
ECU —-1 min
ECU —-1 hr

Question 18

Was the APU designed to run unattended during ground operations?

Answer 18

Yes

Question 19

What is the rpm overspeed that will auto shutdown the APU?

Answer 19

> 106%

Question 20

What valve opens to allow bleed air to the engines & PACKS?

Answer 20

LCV (load control valve)

Question 21

Max altitude for main engine starting with APU?

Using the APU for A/C?

Answer 21

25,000 ft

25,000 ft

Question 22

If APU door is open in flight with the APU off, slow the airplane down until the rpm is ___.

Answer 22

<12%