An automated apparatus comprising: a chassis configured to be mounted on an airfoil-shaped body without contacting its trailing edge; a carriage translatably coupled to the chassis; and an end effector pivotably coupled to the carriage. The chassis comprises: a frame; a motorized drive rolling element rotatably coupled to the frame; a rocker mechanism pivotably coupled to the frame; first and second ball and socket bearings mounted to opposing ends of the rocker arm; and a third ball and socket bearing mounted to the frame. During a maintenance procedure, the airfoil-shaped body is oriented at a non-zero angle of attack with the leading edge higher than the trailing edge and with the balls of the ball and socket bearings in contact with the airfoil-shaped body. A gravitational force exerted urges the chassis toward the trailing edge of the airfoil-shaped body for all chordwise positions of the carriage.