apu engines

Question 1

how many alternators and kva?
kva for engines?

Answer 1

3 - 30kva
2 - 30kva
Above 35,000 25kva

Question 2

what speed and alt can apu be used?

Answer 2

up to 20,000’
141 and 290kias

Question 3

during apu start before you turn on the generator, what cas illuminates?

Answer 3

apu gen off

Question 4

what happens when you press apu pwr/fuel?

Answer 4

1. apu fuel pump energies right tank
2. apu ecu pwr on & run self test
3. 2 fuel sov’s open (fuel and neg g)
4. eicas lights au egt & rpm

Question 5

where does apu get it’s fuel?

Answer 5

primary from right main tank which helps cool the apu generator

secondary from left engine motive flow system in case of blockage, apu pump failure, or neg g’s

Question 6

how many start attempts for the APU?

Answer 6

3 start attempts 30 seconds each
then 20 minutes cooling
2 more attempts 30 seconds each

nj 3 starts in one hour

Question 7

max altitude for start?
min start for start on the ground?
max temp during start?
max altitude for bleed?
max speed for start and operation?
hung start?

Answer 7

20,000’
-40c
974c
15,000
290kts
<30% for 1 minute

Question 8

how long should you wait until you turn on bleeds for the apu?

Answer 8

2 minutes

Question 11

Normal engine start limitations?

Answer 11

3 consecutive starts 60 seconds each. Then 5 minutes cooking between additional starts.

ITT < 120
N2 <= 55%

Question 12

How to dry motor and dry motor limits?

Answer 12

Ignition and thrust levers - off
First attempt 90 seconds
Each additional 30 seconds
5 minutes cooking between all attempts

Question 13

Thrust rev limitations?

Answer 13

Ground only
No more than 60% N1 below 60kts
Not for use in flight
No touch n goes
Do not back up the airplane with tr
No takeoff for
-REV in N1
-rev unlock message
-rev u safe message