Surplus1 your comment below got uneducated little me thinking:
I would suggest that a ‘near vertical trajectory’ (descent) – in a level or flat attitude - is not possible unless both wings are fully stalled – the aircraft isn’t flying, it is falling and there is very little ‘forward motion’. I would postulate further that in such a prolonged “stall” condition a spin of some type, would almost certainly develop. If there was a “spin” there would also be rotation. If there was a conventional spin, the nose would be down – unless the ‘spin’ was a “flat spin” – in which the tail could be down and the nose up with reference to the horizon. The BEA made no mention of “rotation” on impact.
You also mentioned the T-tail shadowing. I know enough to be dangerous so I immediately flashed on T-tail shadowing when reading the above paragraph. In a nose high attitude with the wings stalled creating a lot of turbulence might that provide some degree of shadowing that would prevent the VS from doing its job and straightening the plane out?
I'm wondering more than thinking I've solved anything. It might explain why the VS stayed attached until contact with the water, as the BEA report suggests.
JD-EE