The simulation-fuzzy method of assessing the risk of air traffic accidents using the fuzzy risk matrix

Modernization efforts in air transport are preceded by analyses to make sure that they do not lead to excessive risk in air operations. The risk assessment methods that have been applied so far are insufficient since their classification of combinations of both the probability and consequences of an event is too rough. The aim of this study was to present a risk assessment method that allows to express risk by using a continuous numeric scale. Therefore, a fuzzy risk matrix is proposed in which both the probability and severity of the consequences are expressed by linguistic variables while the risk assessment is made by the fuzzy inference system. A model based on Petri nets was used to assess the probability of aircraft collision, while computer-implemented expert knowledge in the form of fuzzy inference rules was used to estimate the consequences. Experiments carried out using this tool allowed to assess the risk of a Runway Incursion-type traffic incident transforming into an accident at a tolerable level. Furthermore, it was found that the transition of this assessment to the level of intolerable is possible when unfavorable visibility conditions occur in connection with the delayed reaction of several participants of the incident. The proposed method is general and can be applied in different areas. (C) 2016 Elsevier Ltd. All rights reserved.