bonjour Olivier
Had it not been in parents, I would have included it. "Mostly", then, I take your meaning.
takata
"What is a very rare is the fact that long hauls airliners could be affected at cruise levels and lose more than one probe, or all of them, in a very short window of time (as generaly, it doesn't last more than few dozens of seconds, it is erratic for a short while, then return to normal)."
You may be missing my point. It matters not whether it is B or A. If, (When), pitots crap out, it should be no more notable than other transient failures that must not be allowed to endanger a flight. It may be the way it is presented here, but UAS drill seems a bit more of an event than it needs to be. If FMS can quench the 'fire', fine, if it gets wippy and cannot, also fine; there is a critical point, seemingly accentuated by indecision, at which the safety of the a/c and its people seem in doubt.
FIX IT.