Originally Posted by henra
Originally Posted by takata
In case of (d), ECAM messages (FLR) are compiled into Current Flight Report (CFR) sent by ACARS when they are linked to the same fault (having the same ATA). The priority would simply be PROBE-PITOT fault over ADR fault during the correlation window.
In this case, ADR 1+2+3, being not displayed (no BUSS), it would nonetheless trigger three ECAMs:
- ADR 1+2
- ADR 1+3
- ADR 2+3
Wouldn't there have been also ECAM messages in case b) or c) if during the correlation window of 10s the speeds would have fallen more than 30kts (which was very likely the case) ?
The correlation window that I was talking about is the one lasting 1 minute for PROBE-PITOT 1X2/1X3/2X3 and the four other "FLR" ACARS that were reported during the flight. When a failure (FLR) is detected, independently of what the ECAM is displaying in real time in the cockpit, the Central Maintenance System (CMS) opens a 1 minute window during which all the correlated failures (same ATA) are compiled into the same CFR (Curent Flight Report) and a single ACARS is queued for sending when it is closed - in between, each message header could change during this compilation following a particular logic. The full details about such a failure message are only available by accessing the PFR (post flight report).
This system is for maintenance, not investigation. What really matter is that, at arrival, the maintenance must look at the PITOTs and not waste its time for troubleshooting ADRs or the flight Computers which reported in fact this pitot's failure.
This particular "FLR" ACARS was sourced/correlated with:
- EFCS2 & EFCS1 = Electronic Flight Control System 1 & 2 = Flight Control Data Concentrator (FCDC) 1 & 2
- AFS = Auto Flight System = Fault Isolation and Detection System (FIDS).
Hence, during this minute, those systems could have reported other "FLR" with the same ATA that could have been compiled within this reported ACARS.
The CAS falling suddenly triggered two other CAS monitoring functions different from this ADR self-monitoring discussed here. Beside PROBE-PITOT ECAM, the other Flags and Warnings time stamped 0210 were correlated with this sudden fall of speed, whatever ADR (external) fault was or wasn't reported. The second class 2 "FLR" at 0210 (27-93-34) points at FCPC#2 (PRIM2)
OR a connection between FCPC2 and ADR1; BEA correlated also the two Maintenance messages (FCDC1 & FCDC2) to this fault. Maybe we'll got more details from their last findings about system fault logic and cockpit ECAM.