Originally Posted by
CONF iture
If data are known to be corrupted the simplest thing to do would be to cancel automation : Direct law - No autotrim
Every Boeing pilot flies that way in manual flight, is it an issue ?
Not true (ref: Birgenair, Flash Airlines, Turkish 1951 among others).
Remember that Boeing pilots trim manually regularly, whereas FBW Airbus pilots do not. At which point the question must be asked whether a drop to Direct Law - in which pilots are expected to trim manually despite it not being part of their day-to-day operational habits - would be more risky than less.
Failure modes are intended to reflect as close to the normal systems behaviour as possible, not some nebulous definition of what constitutes "real piloting" and what does not.
2) ALT LAW + Autotrim amplify the severity of the stall.
Only if the pilot makes and continues to make inappropriate inputs.
Sidestick neutral, the THS would have rolled the same way.
Not true - or your definition is too loose. If sidestick was neutral from the beginning (i.e. if the PF had not commanded an inappropriate climb and 15 degree NU pitch angle) then autotrim would have never commanded THS to an extreme angle.
It is unacceptable the BEA simply ignores the matter.
They don't - the THS angle in response to PF input is noted in detail. It is not for the BEA to derive conclusions based on that unless autotrim behaved contrary to design.