 Thus, the Avion was intended to be used as a replacement for the Yugoslavian Air Force's fleet of around 120 Mikoyan-Gurevich MiG-21s.Development was a recognised priority programme for the Yugoslavian People's Army and was partly funded by the national government out of general research and development and modernisation funds, as well as being partly provided by industry.The Novi Avion was to be Yugoslavia's first supersonic aircraft, accordingly, the national industry lacked experience in the design and testing of such fighters and sought out external partners to provide assistance.