What is a common method used to test the integrity of composite materials on LO aircraft?

Ultrasonic testing is a widely recognized method for evaluating the integrity of composite materials on low observable (LO) aircraft. This technique uses high-frequency sound waves that are transmitted into the material. When these sound waves encounter boundaries and imperfections within the material, they are reflected back to the transducer. By analyzing these echoes, inspectors can identify internal defects such as delaminations, voids, or inclusions, which are critical for ensuring the structural soundness of composite materials.

Composites are often used in LO aircraft due to their strength and low weight, but they can be susceptible to unique types of failure not typically seen in metals. Ultrasonic testing provides a non-destructive way to assess these materials without causing any damage, making it an essential tool in the maintenance and inspection of LO aircraft.

Other methods such as X-ray inspection or magnetic particle testing, while useful for certain materials and applications, are not as effective for the layered and intricate nature of composites. Visual inspection also plays a role in assessing surface conditions but does not provide information about subsurface defects that could compromise the structural integrity of the material. Therefore, ultrasonic testing stands out as the most appropriate method for this specific context.