Answer:
I'm not sure exactly what u mean, but I do know the famous unsolved mystery of Amelia Airheart.
She was a pilot for one thing, one day she decided to embark on an adventure to fly all around the world. But her plane vanished, along with her. She most likely crashed into the ocean, but the remains of her and her airplane are no where to be found amongst the ocean. That is the mystery of Amelia Airheart.
- Hope I helped :D