Originally Posted by Clandestino
However, I believe 1g to be a typo in both French and English versions.
BEA#3 page 17:
Note 1: The appearance of buffet (buffet onset) is defined by an oscillatory vertical acceleration whose amplitude reaches 0.2 g from peak to peak at the pilot’s seat. The notion of deterrent buffet is subjective.
BEA#3 page 44:
Note: Examination of flight test data revealed, based on the frequency and amplitude, that this signature could in fact be that of buffeting. By drawing analogies with the flight tests, the amplitude of 0.1 g at the centre of gravity suggests that the amplitude of the buffeting at the pilot seat is high (approximately 0.6 g peak to peak).
I don't think it is a typo. Buffet onset is defined as 0.2 g and is considered the lowest level of perceptible buffet. The buffet onset boundary is scheduled in the FCOM and QRH. In the conditions of AF447 it occurred at M=0.64 and AoA=7.7 degrees. The 'deterrent' buffet described on page 93 of the Final Report is so severe that it is considered an effective deterrent to further speed reduction, so that in certification stall tests the airplane would be considered 'stalled' and recovery would be initiated as soon as that condition is reached.
P.S. Sequence of AF447 events:
02:10:51 AoA=6 deg, stall warning triggered
02:10:53 AoA=7.5 deg, buffet onset
02:10:57 AoA=10 deg, deterrent level of buffet reached