Chris Scott wrote:
Is there a possibility that Turbine D is right, and that it is the tail section (by which I think he is referring to the aft fuselage)?
Would the debris field alignment (approximately 070/250) necessarily be roughly indicative of the heading at sea-level impact, despite currents on the way down? If the curved piece in the north-east was the aft fuselage, would that suggest the Hdg 250 rather than the 070?
I think
auv-ee addressed this recently - he suggests it's probably more indicative of the underwater currents. I think it also depends on the degree of fragmentation. We also don't know if this is the entire field (though it looks to be).
My understanding[*] is that if parts are relatively intact, you get a sort of ballistic trajectory that depends on the resistance offered by the falling parts. You can see an indication of this in the HMAS Sydney report -- see the final page of:
http://www.defence.gov.au/sydneyii/f...apter%2016.pdf
and again on p 218 of
http://www.defence.gov.au/sydneyii/f...apter%2012.pdf
"As she continued her plunge she would have tended to level off, and she probably adopted a trim by the stern because the shape of the forward part of the ship offered more resistance to the passing water."
The relative distribution of the parts in turn will be affected by underwater currents pushing on them during the time of descent, but unless they further fragment (eg implosion) what you see in the sonar tends to reflect their original shape.
The question of the relation between resting orientation and orientation at impact is something you'd need expert comment on. My lay impression is that a relatively intact airframe would tend to fall through water nose first, as I presume that would offer least resistance.
However, if the wreckage is heavily fragmented, my understanding is that the final debris field is often spread much further, because each individual fragment behaves differently. The pieces which are both densest and offer least resistance, descend fastest and move least with current. Pieces that are lightest and with the most resistance take the longest to fall and are pushed furthest by the current. Other things fall in between.
The sidescan suggests large parts could be contiguous, but the few photos do show a lot of fragmentation of parts - see at
Oprations de recherche en mer : images du site , especially the one titled "Partie de fuselage".
It's hard to tell without seeing more of the cabin, but I assume it hasn't been shown because human remains were visible. From
mm43's post, it does however look like the main part of the debris field is about 400m long out of the 600m shown, whereas the intact A332 aircraft is about 59m long? Given the amount of internal parts (eg galley parts) found on the surface, from both galleys, I assume there were either multiple breaks in the fuselage, and/or rupturing, to allow them to escape.
nb[*] Several people here have already shown that they have much more knowledge than I on this and I would defer to them if the above is wrong.
Also, compare the tidiness of the HMAS Sydney image with the AF 447 one. I don't know enough to know if this means anything.