FWIW, aircraft do occasionally vanish without trace.
G-AGWH was found after 50 years.
A russian built freigter was recently discovered in the Congo jungle +/- 20 years after going missing.
A 737 is believed to have sunk into a swamp.
There are several other similar mysteries, it does happen but hopefully this one will be found soon, until wreckage is found the circumstances and causes will remain a mystery.