Gimbal lock systems having rotatable hub locks

A tiltrotor aircraft comprising:

• a fuselage;
• a wing coupled to the fuselage;
• a pylon assembly tiltably coupled to the wing;
• a mast rotatable relative to the pylon assembly about an axis of rotation;
• a hub assembly coupled to and rotatable with the mast, the hub assembly having a gimballing degree of freedom relative to the mast;
• and
• a gimbal lock system positioned about and rotatable with the mast, the gimbal lock system including a hub lock and an actuation assembly that is operably coupled to the hub lock;
• wherein, the hub lock is translatable relative to the mast between a disengaged position with the hub assembly to enable the gimballing degree of freedom and an engaged position with the hub assembly to disable the gimballing degree of freedom;
• and
• wherein, the hub lock is rotatable about the axis of rotation relative to the mast and the actuation assembly.