As discussed earlier, the BUSS is no solution for the conditions encountered by AF447. If installed, it can only be made available by switching off the three ADR's, which then remain unavailable for the remainder of the flight. Furthermore, it presents misleading information at altitudes higher than about FL250 because it uses a default stall warning threshold value that does not change with Mach, and (as I understand it) the high speed limit is Vmo but Mmo is not taken into account.