 Located in the vicinity of Mostar, it mostly used the Mostar Airport for test flights.By the 1980s, SOKO was working on the Novi Avion project, intended to develop an indigenous fourth-generation, supersonic multi-role fighter that would enabled the Yugoslav Air Force to be supplied with domestically-built modern fighters.The production was planned to begin around 1991; however, the outbreak of the Yugoslav wars and the enactment of an international arms embargo caused the project to be cancelled.