Aircraft striking water and disintegration
A high calibre bullet fired into water gets about three feet. The idea that a 777 would have enough energy to get through 200 feet of water with enough energy to bury itself in the bottom seems surprising to me, especially as it is highly unlikely to be actually vertical at the moment of impact. Perhaps someone with a better understanding of fluid dynamics or, heaven forbid, some empirical data, could explain?
The aircraft is not a solid object; it is a skeleton structure. Water, when impacted at speed, has the effective resistance of concrete. Water is an incompressible fluid; it has no "give." The aircraft will NOT penetrate through the water surface; instead, the skeleton will collapse and disintegrate (the point loads on the skeleton members are way above the points of deformation and failure). To understand this, look at photos of the re-assembled TWA 800 in that hangar on Long Island. Thousands of pieces.
You end up with a large debris field. The denser items will sink; structures where the density of the whole is less than water (which is conveniently calibrated as 1.00) will float. You might be surprised at how much of the aircraft components are less dense than water: all the plastics, the seats, carpeting, various thermoformed panels, clothing, most luggage, the fuel, and so forth. Even sections with aluminum may float if less dense items remain attached, or air becomes trapped in a pocket section. Also, invariably a large number of the bodies will be floating. In both TWA 800 and Iran Air shoot-down in the Persian Gulf by the USS Vincennes, large numbers of bodies floated and were recovered.
The suggestion is made that fishermen would not recognize aircraft parts as being from an aircraft. Perhaps. Yet, fishermen are not going to misunderstand that bodies floating about are from anything other than some disaster. That, at least, would be reported. It is because of these two aspects - large debris field and over 100 bodies, perhaps 200 floating bodies - that it is implausible to me that this aircraft, after six days of searching by over 100 units in calm seas, went down where the search is going on. And if the A/C did not go down on the water, then my conclusion is that it continued North on its flight path and crashed on land. And if on land, then assuredly not in a populated area; the further conclusion is that it bored a hole in the jungle, at a 70-degree (inverted?) angle, making a 30-ft diameter bore hole, and you don't find it. Gone.
Unless, it really did make that 90-degree turn to the West, and kept on flying, and .....