I agree you'd think they would have found some wreckage by now
Why? Needle in a haystack doesn't even come close. And actually, I don't think it's come down in the ocean. Why hijack it, just to take it miles off course and crash it? If you want that, nose-dive it straightaway.
There's "strange goings-on afoot" and I reckon it's been landed, and the authorities have got a good idea where.