Originally Posted by
bearfoil
Right along with doubts about the climb whilst the PF is represented as commanding it, one must suitably indict the a/c for trimming for maximum Pitch UP. What was he THINKING.......
What was she DOING? Certification is mainly a mystery to me; I trust the system to certify a/c to be safe and reliable.
One understands the need for emphatic NU at TO and landing, but in the arena 447 found herself, why doesn't the THS have a LAW LOCK on it similar to the RTLU?
Curious, what would that achieve exactly ? Based on the info we have (and see the helpful timelines previously posted by others) elevator authority alone was sufficient to get 16deg pitch up and fully stalled. THS simply relieved the elevators.
Had THS
not moved, and elevators held 16deg nose up instead, what benefit results ?
Only (as far as I can see)
perhaps quicker recovery - but THS trims for neutral elevator, so they should, and it appears did, still work if ND is attempted. Unless of course we are into deep stall situation (I would say we don't know if that was the case yet), but in that case THS position quite possibly doesn't matter.
It seems that what you really want is more an attitude-protection law - 10deg pitch up in cruise is silly so sorry dave I can't do that.
But we already have that, in a better way, with AOA & speed protections, but these are lost here - because the planes sensors (or at least some of them) are lying and it doesn't know what is happening with sufficient confidence to apply protections.
Should AOA protections degrade to attitude protections of some sort ? More laws / sub-laws ? More variables combinations to learn and find time to actually be trained on. Does that really help ?