AF447 final crew conversation - Thread No. 1

[A33Zab]

@BOAC.

"A// If two ADR outputs are erroneous, but different, and the remaining ADR is correct, or if B// all three are erroneous, but different"


Ref A//. equals Ref B//.


You can not leave this to software (software programmers uses the same human logica,
but humans can add parameters - on the fly - to make a more proper selection.
The reason this NAV ADR DISAGREE and associated drill, is presented to the
crew is to prevent software of outvoting the only GOOD source (if any).

If "2 of the 3 ADRs were giving apparently 'normal' readings" as you stated, this NAV ADR DISAGREE
message would not have been presented on the ECAM!

@Mac the Knife:

10 minutes is 'ages' in flight, so much can change in so little time,
10s is nearly the max. to look back as reference.

For FCPC ADR voting principle see Page 54/55 in BEA Interim #1.