BEA Final Report:
When airspeeds are below 60 kt, the stall warning is no longer available, even though it may be beneficial for it to be available at all times.
Consequently, the BEA recommends that:
EASA require a review of the conditions for the functioning of the stall warning in flight when speed measurements are very low. [Recommendation FRAN-2012-051]
With BUSS activated the SW complies to this recommendation.
this option is still not installed on AF fleet (except on A380 because it is standard equipment)
The BUSS option was available BEFORE AF447.
It seems that requiring an action from the crew to re-engage this automatic system would, on the one hand, lead to a consistency with the autopilot and the autothrust, and on the other hand stimulate a check on the modes and the consistency of the commands presented at the time of the re-engagement.
Consequently, the BEA recommends that:
EASA require a review of the re-display and reconnection logic of the flight directors after their disappearance, in particular to review the conditions in which an action by the crew would be necessary to re-engage them; [Recommendation FRAN-2012-047]
FD will not re-display without crew intervention.