Well, I guess those are all qualified answers; though I would point out both clues used the term "was". Two of your answers would have to be considered as "still are" and the other is definitely a "maybe will be" kind of thing. IOW; wrong time frame. But I will award not one, but two, bonus clues to reward all the participation. Thanks; Ernie P.
What warbird do I describe?
Clues:
1. This aircraft was fast.
2. In fact, it was the fastest of any aircraft, not only of its type (by designation), but the fastest of any of its category (by type).
3. It was considered to be “uncatchable” by its opponents.
4. Considerable thought and effort was put into slowing the aircraft’s landing speed.