Aug 262012
A photo of a Bell Fold-Rotor concept. The Fold-Rotor was a tiltrotor design that used the props for vertical flight and to get moving forward, but for high speed used other propulsion systems (in this case, the turboshaft engines mounted in the fuselage that drove the wingtip props would disengage and become straight turbojets), and the rotors would stop and fold back to reduce drag. It was an interesting idea, but it still had all the weight of a tiltrotor system, and then some, but with added complexity.
