The Venegono plant of the Leonardo Aircraft Division, in collaboration with Competence Industry Manufacturing 4.0 of Turin, is studying a new Engine Nacelles Assembly Line. The assembly line intends to exploit the synergy between reconfigurable tooling and collaborative robots (cobots) to position the components, and an automatic drilling and fastening system. A demonstration cell is currently being designed. The aeronautical components, known for their flexibility and complex geometries, require precise assembly processes to meet the tight tolerance requirements typical of aerospace applications. The inlet cowl, the nacelle assembly focus of this paper, well represents such characteristics of the aeronautical product. The assembly relies on jigs and fixtures, widely used tools in aircraft manufacturing.