A320 CAT 3 single only with no ECAM
Thread Starter
Joined: Mar 2012
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From: Having a margarita on the beach
A320 CAT 3 single only with no ECAM
Hello folks,
The other day shortly after takeoff we had status displaying cat 3 single only without any prior ECAM caution. It remained like this for the whole flight till after landing when it disappeared. My idea is that it could be related to the failure of the electrical power supply split as you need it only for cat 3 dual but I remember also that there is another failure leading you to the same status, I think it's described in the FCTM but I can't seem to locate it. Any thoughts ?
Cheers.
The other day shortly after takeoff we had status displaying cat 3 single only without any prior ECAM caution. It remained like this for the whole flight till after landing when it disappeared. My idea is that it could be related to the failure of the electrical power supply split as you need it only for cat 3 dual but I remember also that there is another failure leading you to the same status, I think it's described in the FCTM but I can't seem to locate it. Any thoughts ?
Cheers.
Last edited by sonicbum; 14th June 2015 at 06:47. Reason: P.s. Yes both fmgc were operative ;-)
Joined: Mar 2006
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From: AUSTRALIA - CHINA STHN
Guessing but...
Might be an internal IR issue.in the 330 this sometimes happens with no ECAM ... Because there is nothing you can do. It simply changes the aircraft status for autoland... Could be something else entirely of course ... Airbus n all....
We tried to switch APs but no results.
Joined: May 2012
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From: Cairo, Egypt
In the FCOM, Under PRO-SUP-22-10-C "Other abnormal procedures", it says that "CAT 3 DUAL" can be recovered by changing autopilots. If it does not work, recycle the FACs.
Doesn't include all MSNs though.
Doesn't include all MSNs though.
Joined: Mar 2007
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From: Here and there
I have posted about this before as we used to see it in old A320s. On the status page would be a message about Cat 3 Dual inop with no warning message. I remember it was something to do with AoA disagreeing.
Thread Starter
Joined: Mar 2012
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From: Having a margarita on the beach
From the FCTM
ONE ADR OUTPUT IS ERRONEOUS AND THE TWO REMAINING ARE CORRECT
The ELAC and the FAC and/or FMGC eliminate the erroneous ADR. There is no cockpit effect (no caution, normal operation is continued), except that one display is wrong and the autoland capability is downgraded to CAT 3 SINGLE.
What do you think ? Might be the case for ADR 3 ? Both PFD were consistent...
ONE ADR OUTPUT IS ERRONEOUS AND THE TWO REMAINING ARE CORRECT
The ELAC and the FAC and/or FMGC eliminate the erroneous ADR. There is no cockpit effect (no caution, normal operation is continued), except that one display is wrong and the autoland capability is downgraded to CAT 3 SINGLE.
What do you think ? Might be the case for ADR 3 ? Both PFD were consistent...
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From: Nowhere near Shinbone Waterhole
I once checked the AoA during once such encounter Tubby and they were within a tight bull's roar of each other. I think the event may be caused electrically although I'd give consideration to ADR as per FCOM.
Joined: Aug 2007
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From: Middle East
According to memory:
One AOA is voted out and computer is using two AOAs.
The faulty AOA could be any one (1,2 or 3). If the faulty AOA is number 1 or 2 then you will not be able to tell which one is faulty as both PFDs will have normal display.
you can find out the value of AOA 1 or 2 using Mcdu but cannot find AOA 3 unless transferring IR 3 to side 1 or 2 then using the bird to determine AOA 3.
In the unlikely event of the other two AOAs bieng consistent but erroneous, then there will be a problem. In this case apply OEB (can not remember the number) which tells to switch off 2 ADRs
One AOA is voted out and computer is using two AOAs.
The faulty AOA could be any one (1,2 or 3). If the faulty AOA is number 1 or 2 then you will not be able to tell which one is faulty as both PFDs will have normal display.
you can find out the value of AOA 1 or 2 using Mcdu but cannot find AOA 3 unless transferring IR 3 to side 1 or 2 then using the bird to determine AOA 3.
In the unlikely event of the other two AOAs bieng consistent but erroneous, then there will be a problem. In this case apply OEB (can not remember the number) which tells to switch off 2 ADRs
Thread Starter
Joined: Mar 2012
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From: Having a margarita on the beach
Thanks
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From: Vice city
Had the same a couple of weeks ago. Probably rejection of one ADR without warning. We had the same due to a TAT birdstrike which resulted in rejection of ADR 2 due wrong data (TAS, W/V readout and computations)
Once on the ground the cat 3 single status message was gone because the a/c is not sensing airflow anymore so data was correct again and ADR was back in the loop. Worth while crosschecking all the pdf/nd values for all adrs
Once on the ground the cat 3 single status message was gone because the a/c is not sensing airflow anymore so data was correct again and ADR was back in the loop. Worth while crosschecking all the pdf/nd values for all adrs
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From: Depends
Had this occur to us in the past, and as in "The Bird" case it was due to a ADR being rejected after some moderate turbulence. Had us perplexed as well until the engineer on arrival told us it was due to one of the ADR's being rejected by the other two.
