APU

Question 1

The APU pull fuel from which fuel cell?

Answer 1

AFT

Question 2

What is the average fuel burn rate for the APU?

Answer 2

Approximately 175 lbs per hour

Question 3

What provides starting power for the APU and what pressure should it be during Pre-flight?

Answer 3

Utility Hydraulic Accumulator, 2600 psi

Question 4

What drive shaft connects the APU to the Transmission?

Answer 4

Number 7

Question 5

In addition to turning the accessory section of the trans mission the APU also provides _________ and that is control by the __________.

Answer 5

IPAS air, Load Control Valve

Question 6

During an APU start, the _____ is closed, which closes off the APU bleed air port to the IPAS manifold. The Electronic Control Unit (ECU) opens the _____ when the APU reaches ___ Ng.

Answer 6

LCV, LCV, 95%

Question 7

Normal PTO clutch engagement occurs at _____% APU speed. Cold weather (__°F read from the transmission temperature transducers) or main rotor speed above _______% Ng, PTO clutch engagement will automatically occur at _____% APU speed.

Answer 7

60%, 0 , 94-96%, 95%

Question 8

When does the “on” light up on the APU start Button?

Answer 8

95% Ng

Question 9

Do not operate the APU for more than ____ minutes at a main transmission oil temperature of ____°C. Shutdown APU to prevent damaging the transmission accessory gearbox.

Answer 9

5 , 120-130

Question 10

APU compartment fire

Answer 10

(1) On Ground:
(a) APU — OFF.
(b) Illuminated APU FIRE button — Press and RDY light illuminates.
(c) FIRE DISCH button(s) — Press.

(2) In Flight:
(a) Illuminated APU FIRE button — Press and RDY light illuminates.
(b) FIRE DISCH button(s) — Press.
(c) LAND AS SOON AS POSSIBLE

Question 11

Extended APU Ground Operations. During prolonged ground operations greater than __ minutes, observe XMSN TEMP 1 and XMSN TEMP 2 on the SYS page. If the temperatures exceed ______° C. The APU shall be shut down and allow the oil to cool for ____ minutes

Answer 11

30, 130, 30

Question 12

APU Operating Limitations. APU operation is prohibited during normal flight. After a fault or aborted start, wait ___ seconds after APU has stopped before attempting another start. After___ consecutive start attempts, wait ___ minutes before third start attempt. No more than 3 start attempts are permitted in one hour.

Answer 12

30, 2, 20

Question 13

Avoid prolonged operation at _________% NR with the APU running.

Answer 13

94-96% Nr

Question 14

Do not operate the APU for more than __ minutes at a XMSN TEMP1 or 2 of ________° C.

Answer 14

5, 120-130

Question 15

The APU consists of an ________powered driven APU boost pump which draws fuel from the _____ cell.

Answer 15

electrically, AFT

Question 16

What is the purpose of the APU?

Answer 16

Drives the transmission accessory gear box and provides IPAS air.

Question 17

To prevent accidental APU start during maintains what should be done.

Answer 17

The APU ECU PWR/START circuit breaker located on ELC2 should be pulled.

Question 18

Is electrical power required for an APU start?

Answer 18

Yes, although the utility HYD ACC provide starting pressure, the APU fuel boost pump requires DC power to start.