Originally posted by MountainBear
It's unusual but neither unheard of nor impossible for a crash to destroy the FDR. Most unfortunate..
I would point out one obvious thing which you seemed to have overlooked. Outside of a plane crash of this magnitude, can you think of anything in Nigeria capable of generating enough heat to melt an FDR. I can't.
It wasn't the FDR itself that melted, but only the tape inside, and it doesn't take much for that to happen. Two examples are Lauda Air and Mont St. Odile, where rescue forces arrived only hours after the crash, and recorders just aren't designed to provide heat protection for such a long time.
That still leaves the question why it happened in this case, when locating the crash site and getting there was no problem at all. But I could imagine several reasons, and malicious intent to prevent a thorough investigation would not be at the top of my list.