Well, I know Yeager has said he thought he'd broken the sound barrier in a Mustang, but I don't think any supersonic flight in a piston-engine plane has ever been confirmed. In any event, he's not the pilot I'm looking for. But here's another clue, which may give it away.
Looking for the name of a pilot.
1. An ace.
2. Not a spectacularly high-scoring ace, but he is one of a small number of pilots to have achieved a particular kind of success during the one war he fought in.
3. He is remembered today not for his score, not primarily for the kind of success mentioned in clue no. 2, but mostly for what he did on one particular flight.
4. He was once shot down behind enemy lines and was captured, but he escaped. (This was not one of the things referred to in earlier clues.)
5. The feat for which he is remembered is one that some pilots have done accidentally. He did it on purpose.
6. One of the planes he flew is now in a museum.
7. If you've seen that plane, or even a picture of it, you almost certainly remember it.