DJ77:
With this in mind and noting that between 2 h 10 min 16 and 2 h 10 min 50 (citing the report) “The PF made nose-down control inputs”, I venture to submit that it is quite unclear what exactly caused the zoom climb to 37500 ft and this is a hint that BEA intends to closely examine this point.
Whether it was pilot induced or something else, this phase of the accident played a major role in establishing the confusion that followed.
The zoom climb and resulting loss of a/s and increase in AoA was the apparent cause of the stall, which the crew either didn't recognize or was unable to fly out of. So, after the loss of reliable a/s, it was essentially the proximate cause of the accident. And the report gives no real hints as to why the PF commanded nose-up. As the FDR didn't record the a/s displayed on the PF's display, it may, in the end, be unresolvable to a certainty.
Although it appears that this accident was a result of incorrect crew response to a UAS, that hardly absolves anyone else of responsibility. Airbus built a flight control system around critical flight data coming from instrumentation that proved, in the end, insufficiently redundant. Thales designed a pitot tube that, although meeting Airbus specs, proved far more prone to icing than did its competitors. AF did not appear to be sufficiently alarmed by previous instances of pitot icing to act to fix the problem with sufficient urgency. And, of course, the training provided to aircrews to deal with the situation proved inadequate.
Lots of blame to go around, based just on what's known so far. I do find it telling, though, that AF seems better at lining up the holes in the cheese than its competitors. That's not to say AF is unsafe; no major carrier is "unsafe" in comparison to competing modes of transport. But no other carrier has managed to have the first instance of hull loss in revenue service and/or loss of passenger life in
four different aircraft types (Concorde, A320, A330, and A340.)
The French have managed superlative safety records in comparable high-tech enterprises (nuclear and high-speed rail in particular). AF appears an outlier in several ways.