During the repair process of the aircraft, it was found that there were several cracks with a length of 125-250mm or so in the splicing of the fuselage skin, all of which were found in the scratches. The investigation found that there were multiple scratches in the skin splicing, which indicated that the aviation scratch detector was caused by the use of shovel or metal sharp tools in the rubber removal. Before the aircraft is overhauled or repainted, it is necessary to remove the sealing glue in the skin lap or joint. When removing glue, use shovel knife, scraper or other metal sharpener, scratch the skin. Scratches on the skin may crack after a certain flight cycle.

Aircraft skin scratch inspection major maintenance applications for spacecraft include aircraft skin and windshield thickness measurements after rounding and removing glass scratches, aircraft scratch detectors, and detection of cracks in the fuselage, landing gear, and engine fixtures. Through the market research, it is found that the main application of ultrasonic flaw detector to crack inspection of aircraft skin.

Mainly engaged in ultrasonic flaw detector of domestic enterprises with foreign enterprises mainly engaged in ultrasonic flaw detector with the domestic product research avic metrological testing technology research institute of Beijing Great Wall the Great Wall in Beijing metrological testing technology research institute was founded in the early 50 s, aviation scratch detector currently he is member of China aviation industry group company, is specialized is engaged in the metrological testing technology, measurement standard and method research and manufacturing measuring instruments research institute. It is a state-level testing institution for testing and appraising scientific and technological achievements of the People's Republic of China, and secretary of the national vibration and shock measurement technical committee.