[quote flinger]By configuring the aircraft as described, it will remain in the flight envelope and not stall. The linked article explains that in ‘normal’ law, the A330 will remain in the flight envelope regardless of the pilot inputs to the controls (autopilot or not). Since airspeed had failed, the aircraft was operating in ‘alternate’ law, and all control inputs were taken literally.[/quote]This ‘normal law’/’alternate law’ behavior is something I find kind of freaky. There should be some sort of ‘audible’ or ‘visual cue’ that it is operating in ‘alternate law’, not just a warning for something else. It is like driving a car that behaves one way under ‘computer assistance’ and another without – (Stabilitrak works this way – and is kind of freaky in adverse conditions.).
What gets me is the following:
It looks like no-one looked at the artificial horizon, so they didn’t seem to notice the extremely high AOA. This device functions separately from the pitot tube.
It also doesn’t seem that they paid attention to the dive-climb and altitude indicators. Combined with high AOA and the altitude spinning downward with a high decent rate – should have clued everybody as to what was going on. Commercial pilots are supposed to be IFR rated. The pitot tube is used for altitude, but only the side vent, not impact pressure. They did get the pitot tube working part way through (giving them good airspeed indication and altitude indication).. and started flying normally.. then with all instruments working, they crashed the plane with poor flight decisions.
The youngest pilot, the one in control, seems to have his driven more by panic than conscious rational decisions. When told by the superior in the cockpit to release the stick from full-back position, that this was part of the problem, this individual grabs the stick and slams it into full-back position again after hearing that they are nearing the ground. If the plane kept horizontal and made contact with the water, it would have been more of a pancake landing – and more people may have survived.
I am amazed that the A330 flight control system doesn’t consider having wildly differing inputs on the flight control as an unusual condition and proceeds to ‘average’ the controls instead. There should be some kind of feedback to the other pilots stick as well as the ability to disable one of the ‘seats’ (imagine a control that decides to fail – would want to disable it). The old systems had the yoke move together.. so you could tell if the other pilot was giving irrational input.
