View Full Version : A350 ENG FAIL
Airbus2012
30th Nov 2018, 14:22
After ENG FAIL on A320 and A330, when going through ECAM procedures, secondary failures, at ELEC , generally the APU is started.
A350 has 2 generators per engine so you have 2 generators remaining. What do most airlines recommend? Start APU or not. Airbus is silent on the matter and we have instructors who argue that 2 generators is just fine and others that argue for starting APU given that aircraft is designed to have 4 functioning generators, why not recover at least one? Thoughts?
Thank you.
spannersatcx
30th Nov 2018, 19:25
The APU will autostart in a TEFO situation, the RAT or APU are only required in loss of both engines (TEFO) or loss of main electrical system, ALL 4 busbars.
Loss of 2 VFG's the FCOM says 'consider' the APU. You can actually dispatch with 2 GEN's inop (1 per side).
So no need to start the APU at all.
Airbus2012
30th Nov 2018, 22:47
Thank you.
Fursty Ferret
2nd Dec 2018, 21:23
It costs nothing to start the APU in this scenario, and if nothing else minimises load shedding.
Your aim is to make life easy for yourself. Should one of your remaining generators drop offline then you'll massively increase your workload, which you could have avoided entirely by starting the APU.
iceman50
3rd Dec 2018, 04:28
F F
Don't you think Airbus would have recommended starting the APU if they thought it was desirable? You do not need to turn the A350 into an A330.
Jetjock330
3rd Dec 2018, 04:38
You could dispatch with APU inop under MEL and the aircraft will have the same outcome, continued safe flight to an alternate. So APU is an advantage and not compulsory.
Fursty Ferret
3rd Dec 2018, 06:52
Don't you think Airbus would have recommended starting the APU if they thought it was desirable? You do not need to turn the A350 into an A330.
Presumably for the same reason they don't recommend it on the A320 or A330 series, yet nearly everyone does it anyway? I'm guessing that if it becomes a recommended line of the ECAM (eg "APU (IF AVAIL)... START"), it might have presented problems when writing the MMEL.
Don't have the A350 FCOM or MEL - can you dispatch with APU and 2 VFGs inop?
iceman50
3rd Dec 2018, 07:14
Airbus have "Consider APU GEN" use in the A330, they don't in the A350.