@A0283:
"Before doing that, my line of thinking on water landing (before I read your reply, so there may be some duplication in it) was roughly thinking about two different and both basic scenarios."
I’m not sure how much more I can add to my previous post without getting too far away from the evidence we have seen so far.
Either of your scenarios are possible, though judging by the condition of the fuselage (slightly pancaked – side bulge flattened top) as shown in the latest underwater pics, it would have been at a very high rate of descent – so I think both unlikely. However, I also agree that the damage to the airframe looks less extensive than the pictures I have seen for the AF447 wreckage, though a lot of bits and pieces can separate when a journey of 4k to the seabed is involved.
Like others on this forum, I am minded to believe that QZ8501 experienced a similar aerodynamic event to that which occurred to AF447, with the airframe basically intact and in a stalled attitude until impact with the ocean. The more important questions that need answering are how did the aircraft enter the uncontrolled state, and why was it not possible for the crew to regain control – was it a technical failure, or was crew incapacitation a cause. However, unlike AF447, we do not need to wait 2 years for the data recorders to be recovered. Hopefully this information should be revealed in the coming weeks or months.
The following link is instructive in providing an idea of how an airframe, a B737) in this instance, crumples when subject to a test 30-ft/s impact velocity, albeit that in this case the impact is on a hard surface.
http://www.cs.odu.edu/~mln/ltrs-pdfs...-3ikus-elf.pdf