This reminds me of that Twilight zone episode where the plane hits the Jet stream and goes back in time and “no trace of her was ever found”. It could have been BOO who blew it up (Brothers of Obama) but I have a funny feeling it’s something else entirely.
I can really only think of one scenario where a plane completely disappears from radar and then existence without any mayday call.
It involves either a surface to air missile, an air to air missile, or a bomb smuggled on board somehow.
if it were the latter, I think someone would have claimed credit for there successful terrorist act by now. If it were the former, I think the responsible government would be very carefully covering things up.