Originally Posted by Machinbird
#2 Buffeting apparently was not a strong and effective deterrent to the crew of AF447 and the Captain back in the cabin apparently did not recognize it either.
The AF447 pilots probably mistook it for an indication of overspeed. At high altitude there isn't any appreciable difference between high-speed and low-speed buffet as both are caused by the same aerodynamic phenomenon (an oscillatory interaction between local shock waves and airflow separation).
The certification pilots probably considered the buffeting to be "a strong and effective deterrent to further speed reduction". BEA says as much in a note on page 54 of IR#2: "The stall manifests itself particularly through vibrations." (I take it that "vibrations" is franglais for "buffet").
In the video of a TV emission that was posted
a little while ago on the other thread, the AB Chief Test Pilot also seems to talk about "deterrent buffet" (at 34:50), but my understanding of spoken french is not good enough to understand what he says. Maybe one of our french contributors could help?