ASSESSMENT OF ACCIDENT AND COLLISION RISKS IN PRESENCE OF FUZZY THREATS TO FLIGHT SAFETY

The article substantiates the principles of developing a single approach to solving the problem of evaluating the risks of accidents and collisions not only in the field of aircraft safety, but also in areas of military operations, ecology, finance, industrial projects, in air traffic control systems and in counter-terrorism activities. The interpretation of the notion of “risk” as formulated by NASA as “a measure of the forecasted amount of danger” (similar to the Russian Academy of Sciences) is adopted on the basis of the provisions of the risk-oriented approach in the development of the ICAO-recommended safety management systems for aviation safety such as the Safety Management System (SMS). Adjustments have been made to the probabilistic interpretation of rare events. Classical probabilistic indicators may be unreliable in case of insufficient amounts of statistical data on events; therefore a scheme for the analysis of rare events from the Berkeley School (USA) – the Fuzzy Sets approach – has been adopted. The concept of “indicator” provides some tools for “weighing risks and chances”. It is shown that promising developments are based on the Boolean logic of constructing event chains in systems when creating a “collision equation” for a system with a given structure and a predictable risk event, for creating an SMS without the Monte Carlo method and using a new NASA interpretation of the risk of negative consequences. The tool for solving these problems is the method of fuzzy sets for assessing the aviation safety levels without probabilistic indicators. This enables development of procedures and mathematical models for determining integrated levels of safety based on the concept of the functional failure risk. The paper provides examples of constructing the collision equation and defining the risk area and vulnerability points.