Clandestino, your conclusion “
Both pilots commented that speed display was faulty” (#819) assumes a particular interpretation. The absence of airspeed does not imply URA as depicted by the abnormal drill. Also, if the speed display had disappeared off-scale low this may have reinforced the idea of a stall because of the decreasing speed.
Note similar difficulties in determining an UAS situation in the previous events.
Re “
Stall...recovery...in...normal...law...was...never...trained”.
You may have overlooked the nuance of my hypothesis, in that because stall ‘wasn’t possible’ in normal law there was a mental conflict with a stall warning and low speed / decreasing speed, before any appreciation (if at all) that the aircraft was in Alt Law. The erroneous mental model might also have been reinforced by the concern over turbulence from adjacent Cbs.
Thus whether trained or not, the PF chose a course of action closest to the perceived situation based on previous experiences / bias. This was to fly a stall recovery based on a false mental model, and with both supportive and conflicting indications of that model.
Therefore the dismissal of the ‘alternative view’ (#816) might be premature. This may involve
fundamental surprise - when events occur that challenge existing beliefs. Here there is a strong temptation to find situational solutions which fit the information (check Pprune), and thereby miss the opportunity to learn from a wider (fundamental) view of the accident.