The Mule, a logistics UAV uses a Fancraft louvered internal-rotor lift and propulsion system. Far less expensive than the V-22 Osprey tiltrotor aircraft. http://en.wikipedia.org/wiki/V-22_Osprey
The Mule, a logistics UAV uses a Fancraft louvered internal-rotor lift and propulsion system. Far less expensive than the V-22 Osprey tiltrotor aircraft. http://en.wikipedia.org/wiki/V-22_Osprey