The application of endoscope inspection method can reduce unnecessary disassembly and assembly of aircraft and engines during maintenance/repair, reduce the consumption of maintenance personnel, working hours and equipment, improve the efficiency and quality of aircraft maintenance, and reduce the maintenance cost. This method USES optical fiber as the light source, and USES rigid or soft endoscope hole detector and photographic equipment, etc., to detect the internal surface of aircraft and engines through the inspection holes reserved on aircraft and engines.

The use of fluorescent (or dyed) penetrant on the surface of metal objects to check for tiny cracks and defects is the traditional non-destructive testing method used by industry in various countries. At present some advanced countries in front of the aircraft manufacturing and repairing the manufacturer will introduce the endoscopic technique with traditional fluid seepage detection method, developed the uv remote viewing detection (Ultraviolet - RVI) system, also known as fluorescence optical fiber endoscope borescope instrument, used to check the general eyes could not (or not) see tiny crack defects inside the aircraft/engine.

The basic principle of a fluorescent fiber-optic endoscope is that when something is irradiated by ultraviolet light, it fluoresces and can be easily observed. Using this principle, in the detection, the fluorescent (dyeing) liquid infiltration agent daub on the surface of the object, in the removal of excessive infiltration agent and coated with developer, with a black light illuminate the place, can be seen on the surface hair filamentous fine cracks. In addition to the above mentioned functions of the endoscope hole detector system, the compressed air, water, fluorescent osmosis, developer and other materials needed for fluorescence detection can be ejected from the front end of the objective lens, as well as the light source of the black light lamp.