Thanks TXFlyboy. Your information on cargo ships' capacity to transport a fuselage has me reconsidering the logistical possibility of a coverup placing the plane found in the Sunda Trench. And sure, if you can port an entire plane secretly, you probably have the ability to find some corpses to plant, betting that decomposition will do its thing. And easing the fake plane into the water would be more likely to result in the consolidated debri field seen in the ROV footage.
I'm still perplexed why the Sunda Trench. It's near one of the busiest shipping lanes in the world. Further, t's not just off the Sydney-LA flight path, it's the wrong direction entirely. Radar control records would surely disprove such an anomaly. If any 'ole deep trench will do, why not the Tonga Trench, which extends north from New Zealand, and lies in the flight path. I wouldn't worry about whether air traffic passing overhead might see- kind of hard to see 5 miles beneath you, especially if they dump the plane at night, possibly during a window when no flights are scheduled to be pass overhead. The bigger worry is avoiding surface search vessels. Easily solved: it's a big ocean.
It's possible that while the writers were crafting the Find 815 website storyline, they came across this '2nd Bermuda Triangle around the Sunda Trench' nugget. Of course there have been lots of ships & planes lost in the area, given the relatively heavy traffic in this busy shipping lane, frequency of cyclones, etc. Anyhow, the writers probably decided to go with the Sunda Trench for the better backstory, thinking that the vast majority of the audience either wouldn't notice the geographical discrepancy, or would be like the typical American who's clueless about geography. I look forward to seeing whether they explain why the Sunda Trench was chosen, if this indeed turns out to be a coverup. Tho, keeping the Orchid video in mind, I'm still holding some hope that during the electromagnetic accident caused by Des, the Island cloned the ENTIRE Flight 815, just like with the failed teleportation/accidental cloning of Bunny #15. Extrapolating, could the Losties be the clones, not meant to ever leave the island, while the original Flight 815 got teleported to the bottom of the Sunda Trench? Egad, it's starting to sound like a Star Trek storyline:
http://www.jammersreviews.com/st-voy/s5/oblivion.php