xcitation;
There is no evidence either in the ACARS series or any of the BEA Reports and Update that failure(s) of the attitude display(s) occurred.
Initially, (before the pitch-up), this was a simple loss of airspeed data, from which all messages from 02:10:05 until the apogee of the climb may ultimately be traced. In other words, there are no ACARS messages which indicate failure of the IRUs, which supply all attitude information, before the pitch-up.
The ADIRU to which
takata's schematic shows is a dual "ADR"/"IRU" installation. As shown in the schematics below, the ADR part may be separated and otherwise shut off separately from its IRU, (as per standard fault actions set out in the FCOM or on the ECAM).
At the time you claim the "possible" effect (of loss of attitude information) to have occurred (which "causes" the pitch-up), the 3 IRUs remained unaffected by the pitot failure/airspeed loss and would have continued to display correct attitude information after the pitch-up. A change in altitude information would require that the Static ports were affected which would in turn affect both the ADR and the IRU incoming data. By all indications, this did not occur.
Therefore the "original cause" that is claimed to have caused the PF to pitch the aircraft up, is not present.
By the time the IR1 & IR2 FLR messages appear in the ACARS series, the aircraft is seriously stalled and descending at > 10,000fpm.
In different words, if IRU #1 or IRU #2 or both were functioning (we have no messages
before the pitch-up that they weren't), and DMC #1 or DMC #2 or both, were functioning (again, no messages, no comments in the BEA Reports), then attitude information would be displayed normally, very likely on all three indicators.
From this, there is no basis for believing or even positing that any attitude indicator failed, causing the PF to pitch the aircraft up.
Merely saying that it is possible has no relation to whether it actually occurred or not, but the statements above show that normal attitude indications were very likely available.
I'm not dismissing your ideas outright here. I am demonstrating the way an investigative process might function.
A claim that any or all attitude indications were lost requires that the above statements be refuted.
PJ2
Here are the schematics:
ADIRS Control Panel:
ADIRS Schematic - information flow:
For comparison to the ADIRS schematic - the Pitot-Static ADM/ADIRU system. Pitot-static data is fed to the ADIRS for use by both the IRU (
baro altitude, and rate of baro altitude change) and the ADR:
