Some thoughts after the final report
I've been following the AF447 case from the beginning.
PPRuNe has been very valuable to get deeper understanding of what has happened.
Very knowledegable and professional people, and I wish to say thank you.
After reading the final report of BEA, mixing it with the nine or more threads of PPRunE, I still have some question marks in my head.
First of all, if I have understood correctly, if the pilots did not do anything, all this could have not happened. If so, what was the reason the pilots started to, IMHO, degenerate the situation with bad "moves". The plane was stable and weather was not really that bad.
Was there something in the displays the saw that made them to decide to make "corrective" measures? I can understand that many ECAM messages, AP/ATHR disengagement can be disturbing but usually doing nothing is a must until you understand the situation. The pilots seemed not to understand what was happening and still they started to react. Nose up? What indicator or information would warrant a pilot to do that? The only indication of trouble I have read was UAS with some detail low level "nonsense" messages.
Which leads me to the second point. It seems that the pilots (PF, PNF) did not understand that they have a UAS situation. The plane did really nothing to help them to get understand what was really the trouble (non working pitot tube) and instead sent out a load of different low level information that the pilots could not digest in that, for them "critical" situation. Now, when the situation is confusing, the last thing you need is more details. The plane "knew" what was wrong (ADR disagree -> UAS) but did not inform the pilots in a quick, clear manner. It would have been the planes job to analyze those lower level detail problems and to build up a better message to the pilots "One pitot is malfunctioning. Apply UAS/ADR disagree procedure". Now it was left to the pilots to build up that info, from all the confusion and other ECAM messages. Also the messages are quite cryptic, with lot of acronyms and ohter things that puts pilots brains in even more pressure in a situation where the brains are already overloaded. I don't understand, from the engineering point, what is the reason, if not economical, to raise the level of the information in the planes for more easier diagnosis.
Just my humble opinion.