Quote: ADR DISAGREE : TOOK IT A LONG TIME TO APPEAR NOW !
Not surprising; there must be a built in time lag to be able to sample speed trends; otherwise we be seeing ADR DISAGREE with every bit of turbulence.
Re my earlier post on pitot icing and safetypee's helpful comments, a possible senario could be:-
(1) Icing of the pitot drains causes an apparent speed increase, a/c slows toward the stall.
(2) PHC 'catches up' with deicing the pitots, speed decreases.
(3) Software senses imminent stall; pitch down.
(4) Cascade of ACARS messages ...
I don't know what the time lag is on the ADR sampling is, but this could be happening in that time. It could also account for other occurences, such as Qantas.
I'm not saying this is what happened, but it fits what little evidence we have.