On the example of helicopters, the topical issues of systematization and mathematical processing of statistical information taking from fault log sheetsto assess the level of reliability and flight safety of state aviation equipment are considered. The reliability of all helicopter systems must meet the pressing needs of defense capabilities and support the capabilities of the state aviation of Ukraine to carry out combat missions at the current level. Improving preparedness for assigned tasks will facilitate participation in combined operations with peacekeeping and NATO forces. The considered model of the system of aviation equipment on the example of helicopters consists of interdependent, jointly functioning, united by a single purpose of five subsystems of the corresponding type of specialty: “helicopter and engine”, “aircraft armament”,“aircraftequipment”, “avionics equipment”,“navigation and target acquisition system”. Realization and methodical approaches to the development of complex failuremodels of the elements of “helicopter and engine” system by types of helicopters are substantiated. The paper proposes to address on the example of helicopters the lines of approach the problem of assessing the real level of operational reliability and flight safety of aircraft to maintain their serviceable condition. When putting military aviation assets into operation according to the technical condition, using statistical models of reliability and flight safety, the important task of increasing resource indicators is solved, which requires improving the system of collecting, processing and analyzing information from fault log sheets.

The aim of the study is to develop and determine the maximum acceptable reliability factor of state aviation helicopters based on statistics on malfunctions that occur during the operation of the aviation materiel, taking into account the recommendations of ICAO. The paper defines the general criteria for calculating the limit values of reliability (operational reliability and flight safety). For their implementation it is necessary: to carry out constant monitoring of flight safety and the general reasons which cause emergence of malfunctions of helicopters, their systems and subsystems; to use the proposed combined model on the principle of "traffic light" to determine the level of flight safety indicators at their standard deviation when justifying decisions on the forecast for future periods of operation and establishing certain values of forecast indicators of the "upper control limit" of operational Based on the adopted conceptual approach to determining the dynamics of change in failure rates, quantitative criteria are developed. Proposals to determine the indicators of the technical condition during the military operation of the aircraft will maintain high combat readiness of state aviation at a given level, predict the need for maintenance and repair and predict the timing and direction of modernization of aircraft.