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View Full Version : Eng 1+2 bleed inop, QRH and ECAM,


Jimmy Hoffa Rocks
8th Jan 2017, 18:29
Ok so the scenario is you take off with bleed 1 fault deferred MEL.

In cruise you get the CAB PRESS ALT excess warning.

suspecting the other Bleed you go to the ENG 1 + ENG 2 bleed QRH procedure which tells you to go back to complete the ECAM, then to go back to the QRH procedure.

(The bleed abnormal was a OEB item, you used to be able to go to the OEB first but now Airbus says you must do the ECAM first.
Yet you must be sure you cannot reset the bleed before descending right, or you would descend right away, with a mayday with traffic below in congested euro airspace?)

Then after you must go back to the QRH, when exactly?

The QRH procedure enables us to reset a bleed and start the APU.

AIRBUS says do the ECAM and then QRH right?

but before initiating a rapid descent with two bleeds inop dont you want to try to reset the bleed and possibly get a bleed back first?
Starting the apu asap

FlightDetent
8th Jan 2017, 19:12
The narrative seems strange to me.
. What caused the CAB ALT?
. Why not OEB before ECAM?
. Is the A/C affected by the OEB (which was not written to support case with MEL bleed, BTW)?

Jonty
8th Jan 2017, 19:23
Not sure about the narrative on this either.

However, a depressurisation will kill you, so a decent should be started.

If the QRH/OEB subsequently sort it out, great.

Jimmy Hoffa Rocks
8th Jan 2017, 21:28
Have a look at the AIR ENG 1 + 2 BLEED FAULT QRH procedure. Also some aircraft have the bleed OEB others, not. Airbus says do the ECAM first then the QRH, in certain situations may be better to do the QRH procedure then to the ECAM , first. If you agree(?)

Bear in mind Airbus has changed the QRH procedure.

There were flaws in the dual bleed procedure, and unecessary emergency descents with dual bleeds that had a bleed reset.

Interested also a critique of the Airbus procedures. As we are trained to do the ECAM first.

FlightDetent
8th Jan 2017, 22:12
Let's take the MEL config out of the equation first.

Then,
. OEBs substitute any other procedures and shall be executed first.
. if no OEB applicable, then _for dual bleed fault_
-> no applicable ECAM is available
-> use the paper QRH procedure provided for this particular case
. eventually you may get CAB ALT,
-> stop troubleshooting the bleeds and sort this new, top priority issue
-> by following applicable ECAM proc (displayed)
-> possibly actioning full blown EMERG DES

Apply this procedure when both engine bleed supply systems are failed. In this configuration, the CAB PR EXCESS CAB ALT may trigger. In this case, apply the ECAM procedure associated to the CAB PR EXCESS CAB ALT before continuing this paper procedure.

Jimmy Hoffa Rocks
11th Jan 2017, 14:57
Thanks FDetent,

In the event of a eng 1+2 Bleed failure, and the ECAM PR EXCESS CAB ALT annunciation, and a Red cab alt +9500, reset the bleed(s), start the APU.

Declare a mayday as it is a dual bleed, failure, does your company have a different procedure for a emergency descent or a rapid descent ? A rapid descent with a PAN PAN may also work as well?

In this scenario, you are over the Alps, so you choose, Fl 180, as per the apu bleed limitations, why not use 1 pack only ( 22,500 feet ) until you descent to
15000 feet, where you check the terrain MORA, ETC. and can use 2 packs?


Also We know it is not a structural failure, a bleed failure(s) in this scenario, why not increase descent speed in the descent to 300 knots or as required ?
Cheers

sonicbum
12th Jan 2017, 08:19
Hi Jimmy,

If you lose the other bleed after having dispatched with 1 bleed u/s it will take some time before the cabin reaches 9550 ft or so. Consider cruising with a cab alt of somewhere around 7550 ft, the cabin will start to climb at around 5-700 ft/min (depending on the sealing deterioration) that will give you about 1 min 30 sec to try and reset the bleed and if that doesn't work ask for descent with a PAN initially. You will most likely hit the excessive cabin altitude during your descent especially if you were cruising at high altitude and then you transition to the emergency descent memory items and procedure. If the above happens at lower FL with lower cab altitudes you will most likely not get the excessive cab alt.

Jimmy Hoffa Rocks
12th Jan 2017, 10:55
Thanks Sonic, appreciated.

Good info. Thanks Sonicb, cool,

Not all companies, have it, ( in their MEL, does yours ?) but if you have one bleed inop better the captain limits flight at 31500, ( if not in MEL up to the crew and company policy but safer )and not to strain the only good bleed . Also to see if they have the bleed modification kit done on the older 320s.

To quite right to calculate the cabin altitude and therefore at 31000 ( limit ) would start at 6000 feet.
]

vilas
12th Jan 2017, 11:32
Jimmy Hoffa Rocks
I think you are confusing between OEB for Bleed AIR ENG1(2) BLEED FAULT, AIR ENG 1+2 FAULT and ECAM EXCESS CAB ALT. If you get ECAM CAB PRESS EXCESS CAB ALTITUDE it means you cabin altitude is higher than 9550 and it will ask you to EMER descent. No trouble shooting you just do that.
If you only get AIR ENG 1(2) BLEED FAULT then apply the OEB first. The logic of the OEB is to get single bleed two packs operation to cater for pack fault of the existing bleed, by switching off the faulty bleed, opening the cross bleed and monitoring the pre cooler outlet temperature. If the temperature crosses 240C then use only single pack. There is no OEB for BLEED 1+2 fault.
If you get only ECAM AIR ENG 1+2 BLEED FAULT(No EMER DES) then apply ECAM procedure which is also given in QRH. It is basically reset procedure to recover one or both packs. If it doesn't then you need to do emergency descent to FL100 and during descent start APU and if you get APU bleed you can fly at 200.