This paper provides a novel contribution for specifying the role of demand for technological competition. The focus is on the analysis of the mechanisms of technological learning and spillovers occurring in different structures of networks of vertically-related industries. The paper offers a detailed and original empirical analysis of technological competition among suppliers and structure of the network of two vertically related-industries, namely the commercial jet and turboprop aero-engine and aircraft industries. Technological performances of actors are measured through measures of output of the technological activity.