The article is devoted to the modeling of the reliability of the power supply system at civil aviation aerodromes. ICAO standards and recommended practices establish a specific set of requirements for the power supply systems of modern civil aviation aerodromes. Every new project or modernization/reconstruction of aerodrome equipment, on which flight safety depends, must be accompanied by the determination and evaluation of its reliability indicators. This requirement is explained by the fact that failures of such equipment pose threats and can create risks to flight safety during the technological processes with aircrafts at civil aviation aerodromes. In accordance with ICAO safety management standards, all risks at the aerodrome must be controlled and reduced to an acceptable level. The proposed mathematical model of the reliability of the aerodrome lighting system's power supply allows for the determination of its reliability indicators under various failure criteria, assessing the impact of the power supply system on flight safety, and developing a set of organizational and technical measures to ensure and enhance the reliability of the system as a whole, which will undoubtedly have a positive impact on the safety of aircraft during all phases of visual piloting.