What approach is used in non-destructive inspection?

Non-destructive inspection (NDI) is crucial in aviation since it allows for the evaluation of the integrity and condition of components without causing any damage that would affect their serviceability. The practice of NDI involves a variety of techniques, such as ultrasonic testing, radiographic testing, and eddy current testing, all designed to detect flaws or defects while preserving the functionality and overall integrity of the parts being examined.

Through this approach, inspectors can identify cracks, corrosion, and other wear without removing parts from service or causing any harm. This is essential for maintaining safety and reliability in aviation operations, as it enables timely maintenance actions based on accurate assessments of structural integrity without sacrificing the availability of critical components.

The other choices do not align with the principles of NDI. Approaches that involve damaging components conflict with the fundamental goal of maintaining serviceability. Visual assessments might be a part of NDI, but they do not encompass the full range of techniques available. Examination focused solely on external appearances can miss internal defects, which can be critical for aircraft safety.