Originally Posted by takata
So, in fact, the reason should be simply because all ADRs were rejected by they respective IRs (this 0211 FLR ACARS discussed previously). It will become NCD and replaced by ADR source V/S on PFDs.
On a speed base, the IRs decide to reject the ADRs, but still prefer to be replaced by them on a V/S base ... it is getting complex again ...
The IR brings its better behaviour in dynamic maneuvers while the ADR brings its stability in time (no drift of the outputs like in IR).
Now, how to qualify the AF447 event ... ?
Anyway, thanks for your research
takata, that's interesting documentation.