Why loss of AP
If loss of airspeed was the only underlying fault in AF447, can anyone explain why the Autopilot needs to disengage? Isnt the AP taking inputs from pitch, roll and yaw only? I can understand that the autothrottle needs to disengage as obviously that needs a reliable airspeed input. But Ive flown plenty of less sophisticated types where the AP will happily keep functioning despite airspeed and many other system failures. This would allow you to focus on the problem whilst AP aviates and you manually set throttle to an appropriate N1 setting.