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OldEngineer

There is a pages long discussion of the salient design characteristics of the VS and the "36" g arm much earlier than only two pages ago. I'll find it. For now, it was not determined whether the term 36g was used to identify focal stress on the arm at "impact", or as an architectural identifier, nomenclature indexing this part for plans purposes.

As a very general impression, this restraining arm, along with the "Lateral rods" speak to the bandaid approach that may have been applied to mitigating the knocks on the fin from conclusions made about the A300 "weak points" in its VS. As you say, the design is old, my impression is this arm had nothing whatever to do with "planned for" stress of a tail landing in water, but had more to do with retaining the Rudder to the fin in reversal/airspeed events. Not an integral part, but perhaps more like a "leash" in case of hinge failure, or partial failure. As I have said more than once, this is counterintuitive from an aeronautical standpoint; if the Rudder is in danger of pulling the VS completely off its mounts, it would be critical to lose the Rudder rather than both the Rudder and the fin.

An aircraft can be flown with no Rudder (essentially a "trimming device" after all), but without its Vertical Stabilizer, the smoking hole is inside the horizon at best.

If I look closely at the Bolt that fixes the arm tip to the Pinion, I do not see any evidence of failure in tension. Rather, it looks as though whatever bit was lost may well have departed due to vibration (plus tension) or even corrosion, and perhaps not even on this flight. The Bolt is bedded in sealant or resin, and looks absolutely pristine. There is no sign that the bolt was deflected in the direction of the tip.

Beyond this, there is simply no evidence in the photograph of vertical deflection of the Hinges themselves. The Energy needed to pull the VS Rudder assembly vertically and forward completely out of the more robust Fuselage attachments would have deflected each of the seven hinges radically downward, each hinge shows no evidence of this, a vector not designed for, except parenthetically as a follow on to radial strength. The flattened lower 1m of leading edge (VS) could be explained as contact with the top of the Dorsal fin, but that would involve a hesitancy at the forward join in letting go the VS. This leading edge damage is telling. If the fin had parted at altitude, its assumed aspect after "stabilizing" would be LE down, trailing the Rudder. I doubt it fluttered. the weight distribution would suggest the LE impacting the water at speed, and the Resin collapsed in folding fashion, its aft edges held beyond the failure of the Frontal vertical seam.

The forward/bottom corner would enter the water first, explaining the lack of further LE damage upward as the fin tapers in chord and width. This brings us to the relative merits of Two Phase materials v. Metallic.

JD-EE

Howdy. I think the "wave action" was used to explain away the loss of clothing from some of the bodies. I don't recall it being used as support for wave action removing people from seats. At depth, the seat/body would compress, and thus resist reflotation. BEA has not answered the question re: "Seated people" being discovered at all, since seats were not recovered, with the exception of the utility stools attached to the bulkhead cover. I would propose that all who were seated went with their still attached chairs to the place we wish to find.

I think a "full roll" is not required to interrupt signal of the Sat. You would know this. I would say that with the possible exception of the Philippines, a roll past 90 degrees is not at all surely lethal. The a/p can roll the a/c to 50 degrees limit, so the signal break would not need a roll past vertical?

What is your thought re: the transmission of the last reported position? ACARS generated? Pilot/crew input?

mm43

For purposes of discussion, It helps me to picture this accident as one of the most difficult around which to establish a chain of events, least of all a chain of failure. When I suggest the airframe has lost pieces, I am not necessarily attacking the "Intact at impact" postulate. I don't find a fatal fault with "En Ligne de Vol" for that matter, but here is the dilemma: BEA reports a slight rotation at impact. For obvious reasons, this precludes absolutely a "Line" of flight, or "heading". The second problem is this a/c is not anywhere close to what anyone would presume even loosely to be "Flight". It is a ballistic structure falling at an assumed peak rate after calculating drag. The expression is misleading in the extreme, I believe it is not picking at straws to characterize it as such. Again, I am willing to accept a mere "language" misunderstanding. Do you have a thought in re: LRP? Automatic and "Fortuitous" or the calculating mind of a pilot trying to potentiate a rescue after his hopeful Ditch?

Thanks gents,
bear