5.1 All materials on exterior aircraft surfaces are subject to abrasion from airborne particles of various sizes and shapes. Transparent materials are particularly vulnerable to abrasion, since their performance is based on their ability to transmit light with a minimal amount of scatter. Scratches, pitting, and coating removal and delamination as a result of abrasion may increase scatter, reduce transmission, and degrade the performance of transparent materials. Visually transparent materials are required for pilot and air crew enclosures, such as canopies, windshields, and viewpoints. Materials transparent in the IR region (8 to 12 μm) are required for tracking, targeting, and navigational instrumentation.

5.2 This test method is intended to provide a calibrated and repeatable means of determining the relative abrasion resistance of materials and coatings for optical and IR transparent materials and coatings. The test parameters for this test method can be directly related to dust cloud densities and velocities to which transparent materials are exposed in the field.

1.1 This test method covers the resistance of transparent plastics and coatings used in aerospace windscreens, canopies, and viewports to surface erosion as a result of dust impingement. This test method simulates flight through a defined particle cloud environment by means of independent control of particle size, velocity, impact angle, mass loading, and test duration.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.