Originally Posted by
Unhooked
Are you being serious? A faulty AOA vane instructs the flight control computers/stabilizer to pitch the nose down in both the Airbus and the Boeing events, overriding the pilots inputs and you fail to see the similarities. Do you work for Airbus by any chance or are you just being ignorant. In both causes software is attempting to prevent the stall.
Not only Fortissimo but myself being serious, it is like comparing apples and oranges. The Airbus AoA protection is indeed a component of a global envelope protection, in a FBW flight control system. I beg your pardon, my intention is not to give a lecture, but I think I should outline some of the AOA protection features on Airbus for better understanding. If the AoA reaches a value defined as "alphaprot" then the AOA protection activates, and will keep "alphaprot" value without pilot inputs. At this time any stabilizer nose up inputs are inhibited. The pilot's inputs on sidesticks are not anymore a g-load demand but become an AOA demand: the pilot can still increase backpressure on the sisdestick but cannot go beyond the so called "alphaMAX" no matter how much is the pulling: the system keeps the aircraft close at 1 g stall but doesn't exceed it . Let's not talk here about how the autothrust plays the game in "alphaprot". The most important difference that I see is that on Airbus the stabilizer is inhibited in any ANU demand, and gives AND autotrim following the pilot pushing his/her sidestick. That is obviously in a normal condition without mulfunztions.
So there is one big difference: Airbus AOA protection doesn't move the stabilizer at all: it acts on the elevators. It uses three AOA vanes with a voting system. While I am not saying at all that this implementation is the best can be built by the industry, I think it is way different from the path that Boeing has followed with MCAS