In Australia, even the most serious events have not resulted in a loss of control, and were
generally well managed by flight crew. About 70 per cent of stall warnings reported to the ATSB
were genuine indications that the aircraft was approaching the point of stall if the flight crew did
not reduce the aircraft’s angle of attack. The remaining 30 per cent of occurrences were related to
stall warning system problems, although very few of those reported resulted in false stick shaker
activation. Most of the 169 stall warnings reported to the ATSB in the last 5 years that resulted in
genuine stall warning events (usually stick shaker activations) were momentary in duration (lasting
for 2 seconds or less). There were no occurrences reported in this period where a stall occurred,
and no occurrences where the stick pusher activated to prevent a stall occurring. As might be
expected, stall warnings happened in situations where the stall speed increased (due to a
particular (and often unexpected) combination of environmental conditions and flight profile), and
the buffer between the stall speed and the aircraft’s airspeed reduced. The majority of reported
stall warnings (81 per cent) were associated with aircraft tracks in the vicinity of thunderstorms or
other turbulent regions of air, and the greatest proportion of these occurred when the aircraft was
operating at an airspeed close to (or below) the minimum for the current configuration (VRef), at a
bank angle greater than 20°, or when there were sudden and rapid changes in pitch angle or
airspeed.
http://www.atsb.gov.au/media/4359010...-172_final.pdf