JD-EE
I had acquired the impression that all three flight officers aboard AF447 were fully qualified for the left hand seat of an A330-200.
No. Only captains and pilots on their command course qualify for the left-hand seat.
If it is the case your junior/senior distinctions don't quite fit AF447.
I'm afraid it does. The F/O elected by the captain as the pilot-in-charge - and the captain would be a fool not to choose the most senior one - occupies the RHS. The junior one ,the LHS;
That system, which is rather common with quite a few airlines has a few pernicious aspects :
1/- The PF /PM system is severely disrupted : the PM is not able to offer the optimum aid as every system is - from his new position - reversed, and it's not easy to operate switches that are not in the positions one is familiar with. Even more so in the dark or in periods of heavy stress.
2/- Supposing - it's a speculation - that the RHS has lost his flight instruments, the only available pilot is the least experienced one, operating with controls he's not used to...
Furthermore the senior most crew member was not the man in charge.
That happens a lot more often than you'd apparently think.
But it doesn't matter, the one in charge has four bars on his/her shoulders and expects loyalty from his/her crew.