...and how to get rid of alpha floor?
Beside the facts of circumstances which led an Airbus to enter this regime, its not unimportant to know how to leave this flight regime.
Sadly Iberia learnt this lesson on Feb. 7th 2001 in Bilbao on Flight IB 1456.
To state the official Accident Report from the CIAIAC:
"...De-activation of the AOA protection To de-active the AOA protection the sidestick has to be pushed either to 8° nose down for at least 0.2 seconds or to 0.5° nose down for more than 0.5 seconds with α < αmax.
As a consequence of this logic in the activation of the elevator flight control, imple- mented on the ELAC L80 standard computers, it can be stated that: While in flight, if the angle of attack is high, or its value is increasing fast, and at that specific moment the sidestick is pulled fully backwards, the system will detect a very high anticipated angle of attack and, if it is higher than αprot, will activate the AOA protection. Once this protection has been activated, the system will preclude the aircraft from exceeding the maximum angle of attack but, if it also detects that airspeed is diminishing, it will lim- it even further the possible angle of attack, pitching the aircraft nose down to dampen an eventual phugoid movement..."