Thanks mm43, seems that idea that AP was permanently lost stems from interpreting: 1. "This condition is latched until a PRIM reset is performed on ground without any hydraulic pressure." to be applicable to AP inhibit and not just to flight controls law 2. "the AP and A/THR can be re-engaged when the NAV ADR DISAGREE message has disappeared." to mean that AP is inhibited rather than "can" indicates it is possible yet inadvisable to engage the AP before ADR DISAGREE has cleared.
Unfortunately, comprehensive list of A330/40 UAS incidents, such as
posted by Takata is absent from final report. It is obvious that all of the incidents involved blockade of at least two pitot probes, so not much difference from AF447 there. 1.16.2 of the report further refers to automation behaviour. ALTN law mostly remained latched for the duration of the flight yet AP and ATHR were recovered, there were even cases of engaging the autopilot while UAS was underway and following the wrong but agreeing air data.
Gums, pusher and shaker are only really meant for the aeroplanes that don't have acceptable natural stalling tendencies. If you don't need pusher - you don't install it as there's always risk of untimely activation. To mitigate it, pusher must push positively but not with such a force that it cant be manually overridden. That's the difference between alpha protection and pusher - alpha prot can not be overridden, that's why it is designed to shut itself down when there is doubt about the integrity of the air data feeding it and that's what we, very technically, call "alternate law". Perhaps tihs is the reason why it is apparent to you that FBW ignored the AoA - it got ignored because FBW is based on unintelligent computers, it detected that there is discrepancy between AoA and speed but it cannot see the whole aeroplane energy picture and has no memory to remember what was the aeroplane doing for last couple of seconds to make a judgment what is right and what is false. The decision must be made by the system both possessing and properly using intelligence.
Regarding the "flying near the edge" and "absence of G trim", I have to return to the teleological discussion regarding the passenger transport aeroplanes. G trim is useful on fighters, to set it to 1 when cruising to decrease the workload and set it to zero while maneuvering to achieve prompt unload with stick neutral. For aeroplanes designed to spend most of their lifetime in straight and level flight, it would be completely superfluous. Flightpath stability makes much more sense. As for the edge:
Originally Posted by BEA final report, page 44
In cruise at Mach 0.8, the margin between the flight angle of attack and the angle of
attack of the stall warning is of the order of 1.5 degrees, but the stall warning speed
displayed on the air speed tape (in alternate or direct law) will be around 40 kt below
the current speed.
40 knots indicated for the aeroplane that makes only gentle heading corrections while cruising is actually quite enough.
Originally Posted by lyman
No solid facts were in evidence, merely a retort that a shaker had on occasion been ignored.
That a shaker had on occasion been ignored, which resulted in stall, loss of control and subsequent fatal injuries and damage to the property is a solid fact.
That a stall warning was heard and heeded in some cases of A330/340 UAS is a solid fact.
That there were A330/340 crews who believed that stall warning is false but they didn't pull, kept AoA under control and lived to tell the story is a solid fact.