US Patent 10933992 Blade fold system using flap hinge

A rotor system of a tail-sitter aerial vehicle configured to rotate about an axis of rotation is provided including a rotor hub which rotates about the axis of rotation and at least one rotor blade operably coupled to the rotor hub. The at least one rotor blade is configured to rotate about a folding axis between an extended position where the at least one rotor blade is substantially within a plane perpendicular to the axis of rotation and a stowed position where the rotor blade is arranged out of the plane of at an angle less than ninety degrees to the axis of rotation.