APU的主要功用是在地面代替发动机提供飞机电源和气源,并可以用于空中或地面启动大发。APU启动故障的结局则常常是启动失败,这不仅增加了机务人员的维护工作,同时对于缺乏地面保障设备的航站还影响航班正常,因此准确、迅速的排故具有重要意义。 The primary function of the APU is to provide aircraft power and air supplies on the ground instead of the engine and to launch big hair in the air or on the ground. The failure of an APU start-up usually results in a failed start-up, which not only increases maintenance work for the crew, but also affects the normal operation of a flight without ground support equipment. Therefore, it is of great importance to accurately and promptly troubleshoot the APU.