The history of aviation is full of aircraft designed not for military service, but to test bold ideas. Such aircraft are often designated with an “X”—a sign ...

I’ll say right off the bat that I don’t know the answer to the second part of the title. But since a patent was granted, there must be some element of ...

Although work on tiltrotors is underway in many places, the Bell V-22 Osprey remains the world’s only production aircraft of its kind. However, at the ...