The pilot did it deliberately. It crashed in the ocean. The Ocean is very very big. It will probably remain lost for decades.
You are correct. Watch “Drain the oceans on National Geographic” So deep.
Nah. Not any evidence for that.
But lots of things have been lost forever. Just watched a new Titanic show which was terrific, including mention of a ship that had been lost without trace just years prior. Latest efforts to find it were in the ‘90s, some teaser debris found but not trace of the wreck.
Aircraft from WW11 era are still turning up in strange places.
Likely will be found when someone is looking for something else