Suggestion to reduce the speculations
Why not make a short summary and simply repost it from time to time since many do not bother to read the whole xxx posts?
Sort of like this- but by someone more qualified than this oldie
1) Copilot deliberately flew plane into CFIT by dialing in 100 foot altitude into computer and ? reducing thrust. Plane automatically flew into mountain.
2) Copilot deliberately locked pilot out by more than one action, not accidental ,pushing lock switch more than once
3) Copilot breathing sounded normal until end
4) Pilot tried to open door, tried to communicate with copilot, was unsuccessful.
5) Questions as to WHY copilot did this remain.
6) Absent FDR, no mechanical or structural failures are apparent.
7) All else is uninformed speculation
8 ) passengers were unaware until very last seconds.