With two FCC involved, (not exactly sure why), additional failure modes may be detected and again, the function disabled.
I understand how they did this, as it is easier to compare one FCC to another as the AOA vanes are wired one right and one left. What concerns me is this seems like reducing redundancy in some ways, as now you have lost the redundancy of 2 independent FCC's. There must be a whole Fton of cascading scenarios by tying the 2 together.
Doesnt it seem much more difficult to trace a fault through 2 FCC's? Comparing 3 versus 2 seems like far better redundancy and error trapping. Still the same with comparing 2, which one do you pick?