After some very interesting offline discussions (by “offline” I mean via PM’s and emails, rather than open fora) I’m wondering if there are any techies (AB / ACARS), or other knowledgeable folks, out there who can contribute information and ideas to this discussion.
Proposition: The initial ACARS messages relating to a “pitot-static” fault (34111506) were said to indicate “faulty airspeed sensors.” As far as is (publicly) known there is no information that can establish the “origin” of the fault (or “disagreement”). Much has been said and written about ice accretion, super-cooled water droplets, etc, but there seems to be no basis for a factual conclusion that “ice accretion” was the reason for the fault.
This leads to two immediate questions:
1 What other circumstances (i.e. disagreement among the pitot-static sources) could have generated those same messages?
2 (Flowing from question 1) Could those particular messages have been (for instance) the result of airspeed disagreement due to an unusual attitude of the aircraft?
According to BEA, AF, and AB, there is some ambiguity with regard to timing of events v/s timing of transmission of specific ACARS messages. I suggest that, given that uncertainty, along with the uncertainty of “causes v/s effects” within the actual chain of events, we are left with a still very large realm of possibilities – and very few “probabilities".
Discussion?