AF447

[Will Fraser]

447

0135 established, stable cruise, M.82 FL350

0210 a/p auto disconnect, to include A/THR and ALT LAW 2

0214 last ACARS, last anything.

UNK Entered the Sea per description by BEA

Hypotheticals:

Prior to a/p disc. the pilots noted turbulence. If so, they made a decision to allow the a/p to continue. In this case, they would have been prepared for 'handback'. If they either didn't notice turbulence, or there was none, the a/p disconnected 'suddenly' with a sudden onset of a/c response that was above programmed limits. In other words, the decision was likely made to allow the a/p to continue to fly. It would take a series of coincidences to have occurred (faults) that were simultaneous with a/p disconnect; if not, then a/p disconnect was a result of something that happened prior, e.g. pitot problems.

With Unreliable a/s, my assumption would be that Pitch would be the instantly necessary mitigation (probably to lower the nose if IAS was 'low'.) If the a/p lowered the nose to its limit then dropped out, wouldn't the 'sudden loss' of autoflight call for some time lapse for pilots to get up to 'speed'? Also, without a/p and a nose trending down, (what's to arrest the Nose Down momentum?) could the Nose be quite low, speed building rapidly, and the a/s still indicating 'low'? Overspeed alerts, low IAS, loud slipstream, a handful of other demanding issues, etc. etc.

What would AB Alt Law 2 be doing at this point relative to recovering, especially the controls, arresting overspeed, etc. What is the pilot's expectation of the a/c's behaviour, given that his own SA is limited?

edit. : LeandroSecundo In your translation it is said "the distance is only 119 nm. and the arrow is negligible over such a short distance". Wouldn't any course deviation be enhanced as distance shortens? Isn't three nm 3 degrees in 119 nm? edit. that isn't 'on course'.