AstraMike - Re your # 3179 - "Flat Spin"
Thank you; excellent post.
It seems to me we are pretty close to saying much the same thing, certainly there are many big ifs involved at this stage and maybe always will be. My point was and is to take what seems to be judged as “known” or believed by competent authority and see if it fits anything known in the world of aerodynamics. If there is a fit, and it seems to me that there might be, surely it is interesting and should lead one to wonder about less sure assumptions.
[Emphasis by S1]
The idea is to suggest a solution that allows the evidence to fit, not manipulate the evidence to fit a solution.
That was precisely my intent. Obviously I do not know if a "flat spin" occured. I suggested the hypothesis only because the BEA opined that the aircraft struck the ocean in a level flight attitude with a near vertical trajectory. If that did happen a "flat spin" seemed (to me) to be the only thing that could make it so. It goes without saying that a flat spin or any other type of spin - did not cause the upset but is only a
possible aftermath that
might fit the evidence of a touch down on the belly.
Your description of a flat spin is quite on the mark. The one place we might differ is on what would keep the aircraft in a sustained flat spin. I do not think that possible unless there is a failure of some kind in the tail section or the separation of engines from their mounts, or both. Otherwise, I believe, the "flat spin" would change to a normal spin or a spiral.
The stated impact evidence in the BEA report appears to preclude a normal spin or a spiral.