Edition12
I hesitate to add to pure speculation; but assuming this large object is part of the aircraft, this would mean we're looking at an impact gentle enough to not send big bits to the bottom, less than 12G to not set the ELT off, but solid enough not let anyone on board switch on the ELT if inclined to do so, nor deploy slides/rafts and trail an EPIRB. Does that sound about right?
Can aviation experts make an educated guess regarding the descent pattern followed by a fully loaded B777 as a result of fuel starvation. Does the typical nose up, one wing pointed down, corkscrew rotation hold in such cases. Might explain what kind of debris can be expected at the crash site. Where would be the center of gravity of a fully loaded B777 with empty fuel tanks? Any estimate of terminal velocity ?