Christy Sweet,
Thanks for posting the link to the list of messages. Don't have a maintainence manual but...
FYI - Auto pilot will disconnect at ALTN LAW activation - involuntary disconnect indicated by "AUTO FLIGHT AP OFF" message. ALTN LAW probably activated by multiple ADR disagree / Flags on PFD (same thing).
Also the first (memory) items on the QRH Unreliable Airspeed Checklist if actioned are: Autopilot/Flight Directors and Auto Thrust off.
NAV TCAS FAULT is just a by-product of the ADR problem.
I doubt the ISIS (3-in-1 Standby Instrument) was fully lost: only the Airspeed part as the Attitude is a separate electric gyro powered by the DC Essential or Hot Battery Bus. ISIS Altitude is raw data from the standby static vents (does not go through Air Data Modules) - While pitot icing is likely I feel it is unlikely that the static vents iced up too. So ISIS attitude and ALT should have been reasonable. At the very least ISIS Attitude should have been good
PRIM 1 Fault and SEC 1 Fault - All PRIMs & SECs have ADIRU input but in the case of the SECs it is only Yaw rate - in anycase PRIM 2,3 and SEC 2 were still OK according to the ACARS messages which should have been ample to fly the aircraft. Bit of a mystery there. BTW - I understand QANTAS Flight 72 had slightly different messages i.e. PRIM 1
PITCH FAULT, then PRIM 2
PITCH fault. After that they tripped to ALTN LAW and had no more control problems as it was NORMAL law (improper activation of low speed protection) that was faulty.
If I am reading the messages correctly the Advisory at 0214z (last message) was ATA 31 meaning pressurisation. The pressurisation Advisories applicable are cabin rate > +/- 1800 fpm or Cabin Alt . >8800' - this could be possible without breakup or structural depressurisation as the CPC's (Cabin pressure controllers) may have been getting incorrect data from the ADIRUs.
Whatever happened they certainly had their hands full
