Airspace control and protection is extremely significant task for every state from security, political, economic and other points of view. However, airspace control requires engagement of technology and people. This, in turn, generates certain costs. This paper presents the research results of long-term financial sustainability of the performance of airspace control and protection on the example of the Republic of Serbia. Cost analysis of this task was realized on the basis of information available from open sources, and the KOSTMOD software was applied for the calculation of the long-term financial sustainability. The results of this research are presented in the paper as the credibility scientific solutions. In addition, this research offers a practical method solution of long-term analysis and evaluation, which can be applied in solving this and similar problems, and provides an overview of the importance of the airspace control and protection, not only from military, but also, from economic aspects.