AKA, the Osprey V-22 tiltrotor aircraft
I saw my first Osprey in the wild several months ago from my office window. Commuting home last night, I saw another. On this morning's commute, I saw two flying together.
So far, only the Marine Corps uses them operationally. My office is about halfway between DC and the Pentagon to the north, and Quantico Marine Corps base to the south.