ref Takata's post
2694
As for the pernicious contamination from the ground, I do not share your point because:
1. the system reacted and disconnected the flight envelope protections, showing that it was an abrupt change of air data stream at 0210.
2. the flightpath doesn't show any acceleration of F-GZCP during her whole flight.
3. GPS altitude could be used to control Indicated altitude at any time.
4. Your premise being "loss of control between 0210-0214" is based on nothing acertained until now; this is by far not the only possibility behind this catastrophe.
I think that UNCTUOUS was inferring that the water present in the static lines froze and expanded in the lines at height - blocking the static line and locking in the static pressure. That can happen as a function of:
a. water pooling (flowing from another area after the climb and due to angle of incidence in the cruise)
b. thermal soak (cooling time - explaining why it took around 3 hours)
.
If, in consequence, the sudden ADIRS disagreement precipitated an autopilot disconnect, then it's possible that a loss of control ensued (due to Alternate Law coupled to heavy handed inputs at a height at which pilots aren't used to hand-flying anyway). Very few pilots would have hand-flown at FL300 and above.
If pitch protection is still in force in Alternate Law, during an upset it may well work AGAINST a successful recovery. Anybody who's practiced unusual attitudes knows that once a jet's nose drops significantly below the horizon at speed, you are then battling to not exceed VNE/max Mach by a wide margin. Success there is tied to generating drag via g, after (but not whilst) rapidly finding wings level then pitching back up to the horizon (and using idle thrust/speedbrakes to control the rate of speed increase). All this depends upon having a valid attitude source. If you don't, then the LOC becomes terminal due to disorientation. If pitch protection affects the rate at which you can pitch, then likewise you are probably going to exceed VNE by a VERY wide margin.
That's what likely happened in the 4 minutes immediately prior to the final ACARS msg. Any less rapid a sequence would have permitted at least a Mayday call to have been transmitted.