A320 APU bleed use with engine damaged or not damaged

[Black Pudding]

Airbus 320, use of APU bleed with or without engine damaged. Is there anywhere in FCOM that explains this in simple terms.

[dirk85]

Read ECAM (http://www.ipadecam.co.uk/index.html#inbrowser)

page 2, bleed configuration-eng malfunction

Easier to try all the combinations than reading the FCOM, assuming that you can find it there (the important things are usually well hidden).

Hope it helps.

[Ollie Onion]

Abnormal procedures ‘Eng Shutdown’ Procedure has a little explanation of when you can use the APU bleed after engine shutdown. Without damage there is no restriction, with damage you have to be careful which engine you use it with to prevent contamination from the fire suppressant. If ENG 1 is shutdown with damage you can’t use the bleed at all, if ENG 2 is shutdown then you can shut the bleed crossfeed and use the app bleed to take some load off the good eng.

[vilas]

BP
It's simple if you remember APU bleed architecture. APU bleed is connected to the left of the cross bleed. So if no.2 engine is damaged you can use the APU Ableed for no 1 pack keeping the cross bleed closed. But if no.1 engine is damaged APU bleed cannot be used as the cross bleed has to be kept closed to avoid contamination.

[Black Pudding]

dirk, Ollie and vilas

Thank you for your replies

i am already aware of the scenarios regarding when I can, but I was asked by a trainee to show where in the manuals it explains this and apart from the ECAM display in Abnormal ENG SHUT DOWN, which by the way does not explain if number 1 or 2, I can’t seem to locate any other information. How does ECAM know if there is damage, would it be if the fire push button has been used, then the x bleed open option will not appear. I can’t seem to remember any display saying close x bleed. Does a status ever say close x bleed. If we have used engine 2 fire push button, will it then say close x bleed. Will status always correctly instruct you.

[Cak]

dirk, Ollie and vilas

Thank you for your replies

i am already aware of the scenarios regarding when I can, but I was asked by a trainee to show where in the manuals it explains this and apart from the ECAM display in Abnormal ENG SHUT DOWN, which by the way does not explain if number 1 or 2, I can’t seem to locate any other information. How does ECAM know if there is damage, would it be if the fire push button has been used, then the x bleed open option will not appear. I can’t seem to remember any display saying close x bleed. Does a status ever say close x bleed. If we have used engine 2 fire push button, will it then say close x bleed. Will status always correctly instruct you.

I believe that Ollie just gave you the reference and Villas explanation :)
It's not on ECAM, but look for it in FCOM, ABN, ENG SHUT DOWN......there is a note at the end of that procedure

[vilas]

How does ECAM know if there is damage, would it be if the fire push button has been used, then the x bleed open option will not appear. You got it.

[Black Pudding]

You got it.

would it know if engine 2 fire push button has been pushed to closed x bleed ?

[Goldenrivett]

would it know if engine 2 fire push button has been pushed to closed x bleed ?
It's not that smart.
Despite any fire push button been pushed, the X Bleed valve will open when you introduce APU bleed air. You have to select the X bleed valve closed before opening APU bleed valve (in anticipation - Avoid) or subsequently when you observe the X bleed valve has opened when you look at the pneumatics page (reactionary - Trap).

[vilas]

would it know if engine 2 fire push button has been pushed to closed x bleed ? ECAM will ask you to shut the cross bleed. FCOM will tell you in case of No.2 fail APU bleed can be opened keeping cross bleed shut.

[Goldenrivett]

Hi vilas,
ECAM will ask you to shut the cross bleed.
I've only seen that when Wing Anti-ice is in use. I've not seen ECAM direct to close X Bleed when Wing Anti-ice is off and APU bleed is on.

[vilas]

Hi Golden
This is what I see in FCOM:
 If ENG FIRE pb-sw pushed:
X BLEED ...........SHUT
WING ANTI ICE..............OFF
AVOID ICING CONDITIONS

[Goldenrivett]

Hi vilas,
Correct. That's all I can find also.
I'm confident there is no ECAM advice if X bleed opens with the introduction of APU bleed air - despite Eng Fire PB having been pushed.

[vilas]

GoldenSince ECAM asked you to shut cross bleed manually then APU bleed cannot open it automatically.

[lurkio]

Hi Vilas, I don't recall seeing the line to close it when wing anti-ice is not in use. All I can find is a note at the end of Eng shut down in FCOM.

- If the ENG 1 FIRE pb-sw is pushed, APU bleed must not be used.
- If ENG 2 FIRE pb-sw is pushed, APU bleed may be used, provided the X BLEED rotary selector is set at SHUT.

The implication there seems to be that it is not automatically inhibited by pushing the Fire p/b.

[vilas]

The implication there seems to be that it is not automatically inhibited by pushing the Fire p/b.
Quote (https://www.pprune.org/newreply.php?do=newreply&p=10393883) Off course it isn't automatically inhibited but ECAM asks you to shut the cross bleed. And that's why APU bleed will not automatically open it. FCOM explains when APU bleed can be used.

[vilas]

In short, ECAM senses damage by the pushed Fire button. Then it asks you to shut the Cross bleed manually. Since Anti ice should be symetrically used it asks you to close it. If engine 2 is damaged APU bleed can be used keeping the cross bleed shut.

[Goldenrivett]

In short, ECAM senses damage by the pushed Fire button. Then it asks you to shut the Cross bleed manually. Since Anti ice should be symetrically used it asks you to close it.
That is all provided the first condition is met i.e. "If wing anti-ice ON:" - hence the request to switch "WING ANT ICE .... OFF"
If wing anti-ice is not on - non of that logic is displayed.

If you get a chance, please investigate your simulator ECAM logic with WING ANT ICE OFF, APU Bleed ON & ENG FIRE pb-sw pushed.

[vilas]

There's a whole page about engine shut down. Do you think everything is linked to Anti ice?
 If wing Anti-ice ON:
 If Elec Emer Config:
PACK1........OFF
L2 In Emer Elec, only Pack 1 pb-sw can be controlled off.
L1  If not Elec Emer Config:
PACK (AFFECTED SIDE) ...............OFF
L2 One pack must be closed when wing anti-ice is in use due to precooler performance.
L1 X BLEED (IF ENG FIRE PB NOT PUSHED)...............OPEN
L2 X BLEED pb-sw must be opened to have symmetrical wing anti-icing.
L1 ENG MODE SEL.............IGN
L2 Continuous ignition is selected, in order to protect the remaining engine.
L1  IF NO FUEL LEAK:
IMBALANCE................MONITOR
TCAS MODE SEL  .......TA
 If REV unlocked:
 IF BUFFET:
MAX SPEED ............................................................ .................................................. 240 KT
 If ENG FIRE pb-sw pushed:
XBLEED ............. SHUT
WING ANTI ICE............OFF
AVOID ICING CONDITIONS

[Goldenrivett]

Do you think everything is linked to Anti ice?
No.
Only those lines which include mentions to
"One pack must be closed when wing anti-ice is in use due to precooler performance.
L1 X BLEED (IF ENG FIRE PB NOT PUSHED)...............OPEN
L2 X BLEED pb-sw must be opened to have symmetrical wing anti-icing."
&
"If ENG FIRE pb-sw pushed:
XBLEED ............. SHUT
WING ANTI ICE............OFF
AVOID ICING CONDITIONS"

I don't have access to a simulator any more - if you get a chance please investigate.
I was caught out once by this so won't forget.

[vilas]

[QUOTE] - if you get a chance please investigate[/QUOTE Will do so.

[vilas]

Goldenrivett
You were right. I checked in the sim. The FCOM write up is confusing. With damage the line if performance permits open cross bleed doesn't come. And without icing ECAM doesn't tell you to shut the cross bleed. So you got to remember the APU bleed architecture to know whether APU bleed can be opened.

[Goldenrivett]

Hi vilas,
Thanks very much for your research. I'm glad I wasn't completely dozy that time when I was caught out.