Quote:
Originally Posted by Machinbird 
Suppose the FACs remained engaged in Normal Law and failed to detect a failure of that system. Could the FAC system then activate overspeed protection without an actual overspeed?
This need not be a design issue, it could also be a maintenance issue. In any case, if the DFDR data continues to point to the FACs, they should probably salvage the cockpit and recover those boxes for examination.
Apart from the fact that the FACs aren't where you think they are, I think you'll also find that the ELACs and SECs are the flight control computers that apply the control laws, and not the FACs.
HeavyMetallist, I'll have to defer to your experience on the actual physical location of the FAC computers.
Guess they will have to grab the piece from ahead of the wing (which may also include the cockpit).
As to the exact manner the FACs interface with the ELACs and SECs, my reading of FCOM indicates that it is the FACs that have the function of monitoring the flight envelope and invoking the protections (among other functions). The ELACs and SECs would then implement the response. Take a look at FCOM 1.22.40 Auto Flight-Flight Augmentation-and see if you read it that way.