At the end of the year 2024.South Korea's Jeju Air crash shakes the world.The cause of the crash is still under investigation. In the aviation industry, the cleanliness of parts is critical to ensure the safety of the passengers who fly every day. Even a small amount of grease or tiny particles left on an aviation part can lead to unforeseen disasters.
The Boeing 737, for example, consists of about 600,000 parts, while the Boeing 777 contains up to 3 million parts. From the manufacturing plant to the assembly plant, the parts have to go through a number of stringent cleanliness tests to maintain the cleanliness standards.
The Importance of Technical Cleanliness
Technical cleanliness is critical to the proper functioning and longevity of safety-related components. Excessive or large particles can cause failures of turbines, fuel lines, fuel tanks and other critical components, which can lead to equipment downtime or flight accidents. Therefore, it is essential for the aerospace industry to test the cleanliness of new production parts. For example, after a part has been packaged, a random inspection is conducted to verify that it is clean. Similarly, after a certain number of miles of flight, the oil is sampled for cleanliness testing. If there are excessive contaminants in the oil, the condition of the parts will need to be checked further.
Cleanliness Inspection and Quality Assurance
With the advancement of aerospace technology, detecting particle contamination on parts has become a core aspect of quality control and assurance. Currently, there are a number of standards in the aerospace field that are used to regulate cleanliness testing, for example:
- IEST-STD-CC1246: To standardize the cleanliness requirements for aviation components.
- ASTM E1216-11: Describes a method of sampling surface particle contamination using tape and counting particles by microscopy.
- SAE AS4059 (C, D),NAS 1638 up to NF E 48-651: Specification for cleanliness of aviation hydraulic fluids.
These standards combine different contaminant collection methods and test results can be analyzed gravimetrically or optically as required.
Gravimetric analysis evaluates the total amount of contaminants on the surface of a part but does not provide information on the characteristics of a single particle; therefore, theOptical microscopeAnalysis becomes a critical step in identifying the type and size of a single particle.
Cleanliness has a profound impact on the aviation industry
In the aviation industry, the impact of cleanliness is not only limited to the proper functioning of parts, but also involves overall operating costs and environmental impact. When aircraft parts are exposed to contaminants, it accelerates material corrosion and deterioration, leading to more frequent repairs and higher maintenance costs. In addition, small particles in the fuel system can negatively affect combustion efficiency, leading to increased fuel consumption and indirectly affecting the airline's carbon emission targets.
Future Development of Cleanliness Testing
With the further development of aviation technology, cleanliness testing will become more refined and digitalized. The introduction of automated inspection techniques and data analysis tools will significantly improve inspection efficiency and accuracy. In addition, specific cleanliness standards for different materials and processes will be further refined, providing a stronger guarantee for the safety and reliability of aerospace parts.
If you need to know more about the process, equipment or services related to cleanliness testing, please feel free to contact us and we will arrange our professional staff to provide you with detailed explanation and assistance.
Author：Cleanliness Laboratory Engineer Yang Shengkai／EditorEditor: Yeung Nga Tong
