Smart cities, the complex systems of sub-systems (SoS) become reality. Numerous research stated that smart city transportation systems are a key part of what makes a smart city smart. One of the recent research projects predicted that those transportation systems could be saving cities as much as $277 billion as soon as 2025. The use of Information and Communication Technology (ICT) and urban innovation are the main mechanisms for smart cities to ameliorate problems concomitant with inadequate transportation infrastructure. The paper aim is to explore the smart airport as a decisive subsystem in the smart city. Authors addressed the importance of urban security network needed to enable critical collaboration between interested parties for proactive approach to possible issues. Using a methodology adequate for social research, authors present study case from Australia related to the innovation of current air traffic. In brief, is explained the ongoing importance of building the Western Sydney Airport at Badgerys Creek. The Serbian Government plan to reshape the Surčin municipality by project: "Leap into the Future - Serbia EXPO 2027" is a great chance for creating the first smart airport city. Following the smart airport city planning best practices is possible to strengthen existing public private partnership and improve urban security. The results offer an adequate solution for the current obstacles in Serbia related to the strategic planning and inadequate communication in the process of the realization city smart concept. This paper is a base for further discussion how Serbia can achieve socioeconomic uplift through increased aviation capacity and complementary nonaviation activities in Belgrade, and at the same time respond adequately to the urban security needs before and during the Belgrade EXPO 2027.