A320 CAT 3 single only with no ECAM
Thread Starter
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,420
Likes: 0
Received 0 Likes
on
0 Posts
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 Jun 2015 at 06:47. Reason: P.s. Yes both fmgc were operative ;-)
Join Date: Mar 2006
Location: AUSTRALIA - CHINA STHN
Age: 59
Posts: 261
Likes: 0
Received 0 Likes
on
0 Posts
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....
Join Date: May 2012
Location: Cairo, Egypt
Posts: 36
Likes: 0
Received 0 Likes
on
0 Posts
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.
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
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,420
Likes: 0
Received 0 Likes
on
0 Posts
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...
Join Date: Sep 2012
Location: Nowhere near Shinbone Waterhole
Posts: 201
Likes: 0
Received 0 Likes
on
0 Posts
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.
Join Date: Aug 2007
Location: Middle East
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
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
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,420
Likes: 0
Received 0 Likes
on
0 Posts
Thanks
Join Date: Mar 2013
Location: Vice city
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
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
Join Date: Jul 2006
Location: Depends
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
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.