A SESAR project has completed a 30-month investigation into how to effectively monitor air traffic management systems in order to check if their resilience is adequate and maintained over time. The project consortium designed a framework for measuring indicators of resilience and successfully validated it in extensive trials with operational experts.
The SCALES (Resilience potential and early warnings for air traffic management) project was carried out over 30 months, with SINTEF (Norway) as coordinator and Deep Blue (Italy) as partner. Several operational experts from air navigation service providers (e.g. ENAV, AVINOR, Norwegian Civil Aviation Authorities, Eurocontrol) and pilots from commercial airlines (e.g. SAS, Alitalia), contributed to the project at different stages providing real field data, revising its results and formulating recommendations for its activities.
Resilience is an essential characteristic of ATM since it ensures that the system can maintain service continuity and safety under any circumstance. Several characteristics of an ATM system are key for ensuring resilience (e.g. the level of shared knowledge of its operational people), and these characteristics can be measured and monitored through a set of indicators (e.g. the amount of day by day experiences shared between the operational people). However, these key characteristics for ensuring resilience are different for each system, are not independent from each other and often difficult to identify.
Mindful of the challenges, the SCALES consortium developed a tool to evaluate resilience by identifying and monitoring an adequate set of characteristics and indicators. Using the enterprise architecture (EA) framework, the tool enables an ATM system to be considered from multiple viewpoints . In doing so, the tool facilitates an understanding of how the system works during operations, providing information about its behaviour and about what is important in order to adapt to disturbances and maintain essential functionalities.
The SCALES tool was validated in extensive trials with operational experts, using a set of real events as case studies. In particular, the project considered several instances of challenging “go around” situations to investigate the ability of different systems to handle the resulting events and continue to provide air traffic services to the aircraft involved in the “go around” and to the surrounding traffic. The indication coming from the case studies and from the operational experts involved were used to refine and improve the tool.