Airbus Alpha Floor Protection
The system automatically increases the thrust of the aircraft when speed is predicted to reach or exceed the critical angle of attack.
Airbus alpha floor protection. The flight controls on the airbus a330 for example are all electronically controlled and hydraulically activated. A low energy warning alerts pilots when airplane energy is insufficient to achieve a climbing flight path through pitch control alone. If alpha prot is reached and the pilot still maintains aft sidestick alpha floor protection set between alpha prot and alpha max will be reached. Alpha floor is a low speed protection in normal law which is purely an autothrust mode.
Air france flight 296 was a chartered flight of a new airbus a320 111 operated by air france for air charter. The speed speed speed voice alert repeats every 5 seconds while the condition exists. The alpha floor function is not available below 100 feet ra or during single engine operation with flaps at conf 1 or greater. These newer aircraft including the a320 a330 a340 a350 and a380 operate under airbus flight control laws.
If high angle of attack protection is active the bank angle is limited to. Most of the crash sequence which occurred in front of several thousand spectators was caught on video. On 26 june 1988 it crashed while making a low pass over mulhouse habsheim airport icao airport code lfgb as part of the habsheim air show. High angle of attack protection alpha.
When activated it provides toga thrust. Alpha floor protection a system designed to prevent an aircraft from reaching very near its critical angle of attack because of slowing down too much. From the airbus fast magazine 20 refer to flight manuals for latest info. As the aircraft decelerates into the alpha protection range the alpha floor is activated even if the autothrust is disengaged.
Airbus aircraft designs after the a300 a310 are almost completely controlled by fly by wire equipment. When alpha exceeds alpha prot elevator control switches to alpha protection mode in which angle of attack is proportional to sidestick deflection. Alpha max will not be exceeded even if the pilot applies full aft deflection. Alpha floor protection is inhibited in some cases.