As part of an ongoing effort to automate air-frame assembly at the McDonnell Aircraft Company, an Automated Drilling System has been implemented to perform outer mold-line fastener hole preparation for the AV-8B, Harrier, wing assembly. The skin must be secured to the substructure as the hole preparation progresses in order to assure consistent hole quality and skin to structure fit-up. The development of this capability posed a challenging production engineering problem for McDonnell Aircraft manufacturing engineers to solve. Ultimately, a semi-automatic fastening subsystem was developed to temporarily secure the skin to the structure. This paper outlines the engineering studies and decisions that led to the development of this technology and those that determined its final form.