Originally Posted by
GarageYears
....
I will give you the lack of positional feedback for the PNF, does, on the surface, seem to be an issue worth inspection ....
But, really, were not all the required indications available to both PNF and Captain - surely the ADI and altitude readout alone should have been the only two instruments necessary to figure out the situation, along with the fact the engines were working:
The stick status and its handling was important, as it was a main cause, in two phases, (a) from the beginning of the climb to stall, (b)from stall all the way to the minimum altitude from where the recovery would have been possible.
Seeing, or perceiving directly the handling of the active stick would have been the very easy, unambiguous way, and the very fundamental direct information needed.
The instruments are ONLY AN INDIRECT indicator of the actions on the stick, and are in the same time indicators of other causal elements, and therefore can be ambiguous, and even hide the very cause of a certain behavior.
From a system architecture perspective, the instruments are at one end in "a chain of elements" that among other things do a transfer of information. The "chain" includes further, the "state of the a/c" in space, then the status of the "control surfaces", etc..... The "position/handling of the stick" is at the other end in the chain, the very opposite one.
This "chain" in its function of transferring information, represents from an abstract system architecture perspective several levels of indirection, and translation/conversion of information, which can ambiguate or hide from one end to the other, the information that is really needed, as the AF 447 clearly has shown.