Takata :
That is what I understand from Lemurian "musical chair" ballet.
Or
- the junior F/O was on the RHS and the senior one comes from his rest -->
- Senior F/O takes over RHS
- junior F/O takes over LHS from the captain.
now the Pilot Flying would become the 1st FO from the RHS (not optimum).
This is ok as he's occupying a seat he's used to.
What is not optimum will be the assistance he'd expect from the LHS as all abnormal / emergency procedures require one pilot assuming piloting and communication functions and in our case, that falls on the guy on the RHS, and ther other one operating the systems to deal with the checklist, again from a position he's not used to.
Whatever happened during the first period, at the moment of the first ACARS transmission, we can say with quasi total certainty that the two F/Os were in charge of the airplane, the least experienced one on the LHS...( and that in the most ideal conditions... )
What is quite apparent to me in these instants just preceding the accident is the feeling of a *routine* atmosphere :
- normal OPS, crew not concerned with weather
- as too many passengers were found outside the plane, seat belts signs were not on
- captain ready to take his rest ( in the middle of the ITCZ, that's a sign of confidence in his crew and the weather that I have'nt shown in all my career !)
A picture that drastically changed in the following minutes, as they were just four minutes before the end.