Ralph Nesbitt wrote:
Why the FACS failed to limit flight control inputs & why the rudder limiter
failed to limit rudder travel in this incident are two questions that have
not been addressed.

First question: A300-600 is not FBW and there is no computer interpreting
pilot commands.

Second question: The rudder performed as commanded and did not exceed its own
travel limitations. Under normal circumstances, it would not have broken the
tail. However, it was a combination of rapid complete rudder movement with
side slipping of aircraft which put way too much lateral force on the tail fin
which snapped off.

You need a lot of rudder authority in flight if, for instance, you lose an
engine and need to correct for asymetric thrust. But that doesn't give you
carte blanche to play with the rudder with full left to full right rapid
movements while plane in side slipping and buffeted by turbulence.