<<It is not the first time a 727 has disappeared without trace. This one had a fully qualified crew and was a planned ditching in the atlantic in 1990 due to being low on fuel. It has never been found.>>
Very true. What is also strange about this flight is that, not only did the crew have their families on board, there was never a crash investigation or a real concerted effort to find them. There was some debris found but it wasn't certain that it came from the aircraft. Also, as I recall, there was no water survival gear on board.
The plane went down outside Canadian waters and the aircraft position wasn't well known. Since it was outside Canadian waters, the Canadian government did not feel it was up to it to investigate what happened. And because the aircraft was registered in Peru, I'm told it was too expensive and too far from home for them to investigate. Nor did the US investigate. So this is a unique case where, to my knowledge, a large aircraft was lost and there was no serious investigation to learn what happened.
If anybody knows differently, I'd like to know.