The subject matter of this specification can be embodied in, among other things, a rotary lock assembly that includes an epicyclic gear assembly that includes a sun gear assembly having a sun gear axial aperture defined therein, a ring gear assembly, and a planet gear assembly mechanically engaged to the sun gear assembly and to the ring gear assembly, a lock motor configured to urge rotation of the sun gear assembly, and a screw lead extending axially through the sun gear axial aperture.