Fedja Netjasov

By Tamara Pejovic, Fedja Netjasov and Dusan Crnogorac

Air traffic performance of the European air traffic system depends not only on traffic demand but also on airspace structure and its traffic distribution. These structural (airspace structure) and flow characteristics (factors such as traffic volume, climbing/descending traffic, mix of aircraft type, military area activity) influence airspace complexity, which can affect controller workload and influence the probability of safety occurrence. In other words, all these dynamic and static complexity components can potentially have an impact upon the safety of the air traffic management (ATM) system. Having in mind fluctuation in traffic on daily, seasonal or annual level in certain airspace, a few questions arise: How changes in traffic demand influence complexity and conflict risk? Is there any correlation between traffic demand, conflict risk and complexity? and Are there any differences between seasons? For that purpose, an investigation is performed on FAB Europe Central (FABEC) airspace, based on 2 weeks of operated traffic during the summer and fall of 2017. Air traffic complexity is estimated using the EUROCONTROL complexity metrics, while conflict risk is assessed using the conflict risk assessment simulation tool. Results show that certain positive relationship exists between traffic demand, conflict risk and complexity.

Part of the book: Risk Assessment in Air Traffic Management

By Fedja Netjasov

This chapter presents a conflict risk assessment based framework for airspace planning and design developed for the purpose of preventing aircraft conflicts and collisions. During airspace planning and design process, airspace designers are often guided by the need to increase capacity and/or reduce air traffic controller (ATCo) workload. In order to consider safety risks in a systematic way, the proposed framework contains an additional step—safety risk assessment, performed by safety analysts guided by the risk reduction need. In such a way, they are providing feedback to airspace designers regarding safety issues of their solutions. This chapter presents four conflict risk assessment models, each one developed for different airspace planning level (strategic, tactical, operational, and current day) contained in the proposed framework. Basic development principles for every model were explained together with specific objectives, assumptions, conflict risk concepts, and required input data. Models are illustrated by the simple numerical examples.

Part of the book: Risk Assessment in Air Traffic Management