Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Application of Methods for Evaluation and Prevention of Emergencies in Flight of Unmanned Aircraft A.A. KULIK An analysis of the influence of internal and external infl uencing factors on the flight safety of an unmanned aircraft and a mathematical description of the change in the safety of an aircraft flight is presented using SDC method and fuzzy functions of its variables. The modeling of the assessment of the threat of an aviation accident in case of failures of the onboard equipment of the aircraft and the deterioration of the weather conditions of the flight, which made it possible to identify the threat of an emergency, was carried out. The paper proposes a way to prevent the threat of the emergency under consideration when controlling an unmanned aerial vehicle, taking into account the peculiarities of its operation. The results obtained make it possible to evaluate the possibility of applying methods for assessing and preventing the threat of an aviation accident during the flight of an unmanned aircraft. The proposed methods and simulation results are used in the design of unmanned aerial systems, as well as on-board devices for ensuring aircraft flight safety. Keywords: unmanned aerial vehicle, onboard flight safety management system, assessment of flight conditions, counteracting the threat of an aviation accident, decision support system. DOI: 10.25791/pribor.4.2023.1404 Pp. 39-47.