HazelNuts39;
I wonder if you meant pitch attitude? The AoA at stall is, just guessing, going to be around 14 to 18deg perhaps a bit higher given the wing.
Again, for everyone's information, none of these images "points to cause" - I am providing them only for demonstration and understanding and not for speculation or investigating:
For 212k kg, FL350 the pitch attitude at AlphaProt is almost 9deg; the CBT autoflight software doesn't simulate Alternate law and remains in Normal Law so it correctly pitches down at AlphaProt engaging the autothrust Alpha mode and won't give the pitch attitude at AlphaMax. Snapshot below:
Machinbird;
The 30 knot suggested hidden airspeed dropoff would have been just the beginning. The cavalry charge alarm would announce the remainder.
If I am understanding correcly are you suggesting that crews would not notice (because AoA is not annunciated or THS setting etc?) a 30kt drop in airspeed and "the cavalry charge alarm would announce the remainder"? That's what I'm reading in between the lines. If this is not the thinking perhaps I have misread.
Notwithstanding the one glaring example of a crew not paying attention to airspeed while flying the airplane on approach, a 30kt loss of airspeed in cruise is HUGE; ten knots and the crew is all over it monitoring autothrust response. It's not that uncommon and mountain wave activity is a primary example; speed variations of that order (10 to 15kts sometimes more but less so) are not uncommon in heavy turbulence, but again the crew would be all over it. I've disconnected the autothrust many times and left it at one thrust setting and let the speed wander up and down, within reason of course. In rare, serious displacements such as in substantial up/down drafts in convective or mountain wave activity, one lets the altitude wander just to ensure that a reasonable pitch attitude is maintained; otherwise large excursions and the scenarios outlined by
fdr above can develop. And all this would be open to professional discussion and perhaps disagreement as others may have slightly different approaches but the essentials are what I'm trying to convey here.
In the scenario you're positing, the cavalry charge would signal disconnection of the autopilot long before speed was lost simply because of the loss of the PRIMs. The single chime would announce the disengagement of the autothrust and would also be continuously sounding, announcing new ECAM messages which would be appearing on the lower ECAM and which would be continuously re-prioritizing. As to which ECAM procedure would be prioritized, I have no idea but there would be a lot of them but that's what we train for.
To this end, as I have described before, great discipline would be required under such circumstances waiting until the airplane and warnings settled down so one could do the drills. The absolute first priority is flying the airplane by pitch attitude (which they had) and power both of which should instantly be in the hands of the PF; that is what the Unreliable Airspeed drill is all about. BTW, the unreliable airspeed abnormal does not come up on the ECAM - the first few items are memorized, (which should be obvious) and the entire drill is in the QRH. Examples of the AF drill are shown in the Appendices of the BEA 2nd Interim Report.
PJ2