Abstract: A foldable rotor system for a rotorcraft, the foldable rotor system comprising a rotor assembly operably associated with a driveshaft, the driveshaft being operable associated with an engine, the rotor assembly comprising a rotor blade connected to a grip pin. A swashplate is operable associated with the grip pin in order selectively change a pitch of the rotor blade. A blade fold actuator is operably associated with the grip pin such that the blade fold actuator is configured to fold and unfold the rotor blade about a blade fold axis. During an airplane mode, the rotorcraft can stop and fold the rotor blades so that the rotorcraft relies upon thrust from the engine for propulsion. The rotor blades are folded in a spiral fold path so that the rotor blades remain substantially edgewise, or feathered, during the folding process. The spiral fold path minimizes the aerodynamic drag experienced by the rotor blades while being folded during flight of the rotorcraft.

Abstract: A foldable rotor system for a rotorcraft, the foldable rotor system comprising a rotor assembly operably associated with a driveshaft, the driveshaft being operable associated with an engine, the rotor assembly comprising a rotor blade connected to a grip pin. A swashplate is operable associated with the grip pin in order selectively change a pitch of the rotor blade. A blade fold actuator is operably associated with the grip pin such that the blade fold actuator is configured to fold and unfold the rotor blade about a blade fold axis. During an airplane mode, the rotorcraft can stop and fold the rotor blades so that the rotorcraft relies upon thrust from the engine for propulsion. The rotor blades are folded in a spiral fold path so that the rotor blades remain substantially edgewise, or feathered, during the folding process. The spiral fold path minimizes the aerodynamic drag experienced by the rotor blades while being folded during flight of the rotorcraft.