This thesis performs a factual reliability analysis of the electrical power system for an airplane repair and maintenance hangar. This analysis conforms to the overall system reliability/safety requirement of the actual operations. Under the normal and emergency operational conditions, the system reliability of the airplane repair and maintenance hangar power system was analyzed. The related new technologies and their applications were considered and evaluated for increasing the system reliability. This thesis utilizes the system failure and breakdown records data for the past ten years for the electrical power system. These data were also used to carry out the electrical power system reliability analysis. Generally speaking, the longer the operating time of the electrical power system is, the system reliability will drop as a result. This analysis and research results will provide as a good basis and reference for the repair maintenance staff and workers. It also can be used to improve the overall airplane repair and maintenance hangar electrical power system operations and to increase its system reliability.