This study presents a probabilistic method for assessing the safety and reliability of aviation systems based on modeling transitions between functional and failed elementary states. The analysis includes five core components of the aircraft system: crew, engines, avionics, power supply, and structural elements. Using failure and recovery flow intensities derived from realworld data for various aircraft types in 2022, the authors construct a system of differential equations to calculate dynamic safety indicators. The method applies state-transition graphs and formal mathematical models to describe the system’s behavior under different conditions. Particular attention is given to the non-technical elementary state representing crew condition, with a refined classification of critical human factor events such as specific headache types. The study performs calculations in MATLAB and provides comparative safety assessments for multiple aircraft models, such as Airbus (A-319 and A-320), Bombardier CRJ200, Boeing (737, 747 and 777), Sukhoi Superjet 100 (RRJ-95) and An-26B-100.