Unauthorized guest
Re. Lemurian's post 1555,
"---- The first possibility is frightful : we are talking about a major safety breach here and way beyond my theory of a less-than-optimum operating flight deck crew.
The only thought that comes to my mind is, that close to the crew change-over, that there was only one pilot up front when the chips went down. In this speculation, the flight deck door is locked, without any possibility for the other pilots to regain their seat as the one left on his own was too busy .
Why am I thinking about that possibility ?
It was a theory, one among others, said a long time ago when it was learned that one of the pilots was traveling with his wife in J."
This speculation seems to fit much of the circumstances reported by Le Figaro - A330 exonerated, crew and AF security the causation, and dovetails with other subsequent post speculation. i.e. post 1580.
Sadly, as mentioned in prior posts, there is/are precedent(s) of an "unauthorized guest" in the cockpit contributing to the loss of an aircraft.
Speculating further - perhaps in the case of AF 447 there is a coincidence with an undetected weather event occurring immediately after a crew change with the "guest" in other than the jump seat.