3
I don't consider it related to this accident (RTLU). I didn't say it was.
I said that as a consequence of degraded Flight Law, the Rudder Limiter prevents extension beyond certain speed (calculated) limits, to prevent damage.
I compared it to a THS which in Alternate Law, is NOT LIMITED in deflection, and in 447's case, migrated to its NoseUp stop.
The comparison was meant to highlight the decision AB made on the one hand to protect a flight control from damage (Rudder/Vertical Stabiliser), and a disregard for potential Attitude problems caused by an unlimited TRIMMING DEVICE.
There are some well established pilots here who have noted this problem with autotrim.
Not only is this autotrim without designed limits, it works without notification to the cockpit. (Sorry, not correct, the pointer on the manual wheel shows the THS' deflection).
So this sets the stage for some (what I would call boneheaded) design that arguably is responsible in a very demonstrable way for the outcome of 447's flight path.
Did the THS prevent RECOVERY FROM STALL? It does not matter, strictly speaking. The fact that it deflected automatically into a position that caused potential threat suggests a serious flaw in the design of the Aircraft.
Now the argument can be had, (and is) that the PF was ___, ____,_____, and _______, but that is a dodge, intended to distract from the fundamental problem.
As to Attitude, the selfsame lack of design can be isolated and criticised. The Displays were "acting up", and one must admit to some possibility for the various displays to be unreliable, or transient, or gone. So an AH driven independently of the system that was in trouble seems a no brainer, at least to me. One would have to have a good argument against it to say it was not necessary. Clearly, if available, it MIGHT have helped.