hydraulic forces
So are you guys saying, the over-pressure wave from compressing the inflated balloon of the aircraft is what shatters it into manifold pieces? But that does not explain how pylons become separated from wings, and the engines themselves be torn apart.
-drl
Let me jump into this for a second. For the AF447 impact, Imagine the skin of the belly was made of aluminum foil instead of ~1mm aluminum alloy. (The hydraulic force from below is so overpowering that the actual skin is little better than foil). The stringers and formers are immediately behind this thin surface. As the aircraft impacts, a considerable amount of this "foil" in the belly of the aircraft simply ruptures from the overload and folds back over its supporting structure. The internal pressure upon the remaining structure above could act to distort some structure above until major ruptures from fuselage bending allow the pressure to escape, but moments later the hammer of a surge of water from below will do the bulk of the damage. Mixed into this surge of water from below is the wreckage of the belly of the aircraft being thrown into the structure above and causing localized damage.
So hydraulic pressure tears up the belly skin, and fuselage bending + flying wreckage from below continues the destruction and tears up the things in the top of the aircraft. This is a macroscopic view.
On a local level within the aircraft, Whatever was below greatly influenced the damage pattern above.
The FDR may well have been thrown up into THS structure with the initial hydraulic induced debris flow.
I really suspect that the THS structure was then pushed up and aft out of the aircraft, throwing the aft part of the VS upward and forward and taking a bite out of the rudder bottom as it passed by.
Although this was a violent destruction compared to an automobile accident, it bears none of the hallmarks of a really high speed impact wherein very little of the aircraft is recognizable and the average piece size is hand sized or smaller.
