Machinbird says: (of post 4426/4427 -
link)
"....Why not a simple deceleration into a stall with heavy turbulence and a cockpit full of warning lights as a distraction? It seems to fit the event time line better."
.
Seems to fail the logic test for Occam's Razor. Up until the A/P disconnect, as far as the ADIRS and PRIM were concerned, everything was nominal. The auto-thrust would have been doing its job in maintaining the sched speed. ........ as the three pitots iced up internally and indicated, to a gullible system, that the aircraft was tending to slow (just as the autothrust would respond, say, if it was picking up a load of wing and fuselage ice).
That means that the speed observed on both the L&R PFD's was (misleadingly), and continued to be,
exactly what the pilots expected to see, but in actuality the aircraft speed through the air was somewhat in excess of that (and increasing as the pitot blockage increased towards, but not necessarily TO, a total blockage). Then the autopilot disconnected and the TCAS dropped out - because the two different sources of static pressure were now in total disagreement. .... and parametrically unacceptable for RVSM flight. Why the TCAS? It needs the static pressure to be in agreement (and good) for a highly accurate RVSM flight level maintenance.
That's what I'm getting from those two links. Suggest you re-read them both.
So the case for it having been a Mach Crit encounter is there (IMHO - and unless some of the cognoscenti have a contrary argument).