Savrin, this is from the June 2009 report:
Quote:
FCPC2(2CE2)/WRG:ADIRU1 BUS ADR1-2 TO FCPC2 (2 h 10)
ATA: 279334
Source: *EFCS1
Identifiers: *EFCS2
Class 2, HARD
This message indicates that FCPC 2 no longer considers as valid the information that is delivered to it by ADR 1 (via bus 2). The ATA code beginning with 27 indicates that the fault was not detected by any other FCPC during the three seconds that followed (otherwise this message would have been classified ATA 34). This message has not been fully explained at this stage of the investigation.
This is from the 30 November 2009 report: Quote:FCPC2 (2CE2)/WRG:ADIRU1 BUS ADR1-2 TO FCPC2 (2 h 10)
ATA: 279334
Sou rce: *EFCS1
Identifiers: *EFCS2 Class 2, HARD
It is possible to explain this message by the rejection of ADR 1 by FCPC 2. It is correlated with the MAINTENANCE STATUS EFCS 1 and EFCS 2 messages.
Neither believes this is a wiring problem. What makes you insist WRG means wiring rather than warning? I realize there are WRN and WRG messages. There does not seem to be a distinction between them as listed by BEA.
A coincidence that would cause an AIRINC bus to quit working in only one direction would be surprising. And if it's not an AIRINC bus (or multiple AIRINC busses) then it's a multipin connector with inputs and outputs on the same connector. Why would only one direction fail? Why would it fail only in modest turbulence and not be discovered before that turbulence? That's too many hard failures at once for my tastes.
No doubt this is a wiring (WRG) problem, either internal in the PRIM2 or in the wiring from ADR1 ARINC BUS 1-2 from terminal to PRIM2 (includes, as JD-EE is correctly stated: the multi-connector). Wiring problems are rather easy to detect, send a test signal and compare with what is returned. It’s all day routine and takes place all the time, devices in control or in standby.
This is a class 2 maintenance message, no big deal if solely reported, it’s still receiving input data from ADR2 & 3
Trouble Shooting Manual is clear, replace FCPC2 = (PRIM2) and if fault persist check wiring from terminal to FCPC21]
Not easy to say in relation to the other problems. [B]“Need more data to compute!” e.g. what was crew-action on ECAM warnings, They should X-check speed and isolate ADR in error. Though job with 3 unreliable speeds but had to make a decision otherwise PRIM (in control) will make a decision which data to be used. BEA report doesn’t mention crew action on warnings neither which PRIM was in control. They only stated ADR 1 was rejected by PRIM in control.
Although only 1 PRIM is in control at a time, other PRIMS do X-check each other, if they disagree with output they will report (not mentioned in ACARS List) and probably transfer control to another consistent PRIM. PRIM 1 and SEC 1 messages most proberly be due to crew action, no correlated fault)
Could PRIM2 be in NORMAL LAW and others in ALTERNATE LAW, Very unlikely because ADR DISAGREE (due to PROBE PITOT 1+2,2+3,1+3) results in ALTERNATE LAW for all PRIMS.
And even when PRIM2 was in control and the only one in NORMAL LAW, ADR data is used for protection, IR/ accelerometers for feedback and control is by AP or SS both in NORMAL as in ALTERNATE.
Software or even program bugs? Very unlikely after all those years! few incidents where reported due to intermix of mod status ADIRUs and/or PRIMs, as far as I know never with disastrous outcome.