The Bell X-1 was the first manned airplane to exceed the speed of sound in level flight and was the first of the X-planes.
References
List of X-1 flights Wikipedia(Text) CC BY-SA
List of X 1 flights
Updated on
Edit
Like
Comment
Similar Topics
The Bell X-1 was the first manned airplane to exceed the speed of sound in level flight and was the first of the X-planes.