A mechanism for transitioning a tiltrotor aircraft between rotary and non rotary flight modes. The mechanism includes a gimbal lock positioned about a mast that is operable to selectively enable and disable a gimballing degree of freedom of a rotor assembly relative to the mast. A blade stop assembly, positioned about the mast, includes a plurality of arms having a radially contracted orientation and a radially extended orientation. A blade lock assembly is operably associated with each rotor blade assembly. Each blade lock assembly is operable to selectively enable and disable a folding degree of freedom and a pitching degree of freedom of the respective rotor blade assembly. A swash plate is operable to change the pitch of the rotor blade assemblies in the rotary flight mode and fold the rotor blade assemblies in the non rotary flight mode.