49 APU Flashcards
When does the APU AVAIL light show?
N >95%
What does the small green triangle above the APU GEN on the APU SD page show?
APU line contactor (closed if green)
Advisory range for APU GEN load?
> 100%
Advisory range for APU GEN voltage?
> 120V or <110V
Advisory range for APU GEN frequency?
> 410Hz or <390Hz
Max EGT for APU on startup?
1090 degC
Max EGT for APU whilst running?
675 degC
When does the APU auto shutdown?
APU shut off switch on external power panel pushed, or
APU FIRE pb pushed, or
APU fire detected on ground, or
APU reaches relevant MAX EGT
Where is the APU fuel fed from?
Left side tank pumps
If the APU SD page shows “FLAP OPEN”, which flap is this?
Air intake flap
How many hours of operation do you have on APU LOW OIL LEVEL?
10
When does the APU MAX EGT turn amber on the APU SD page?
MAX EGT -33 degC
When does the APU N% turn amber and then red on the APU SD page?
102% amber then 107% red
What is the APU battery restart altitude limit?
25000ft
At what altitude is APU bleed air available with 1 pack?
22500ft
At what altitude is APU bleed air available with 2 packs?
15000ft
At what altitude can the APU be used to assist in restarting an engine?
20000ft
What does the ECB set the APU speed to? What about if the ambient temperature is between -18 and +35 degC?
100%
Unless temperature within “normal” range -18 to +35 degC and air conditioning demanded, in which case 99% (APU BLEED ON essentially)
After APU OFF, and APU BLEED was being used, how long will it take for the APU to fully shutdown and the flap to close?
2 minutes
Cooling period after bleed air use is 60s to 120s
