Which of the following is not an FAA approved method of testing?

The statement that IA visual and NDT (Non-Destructive Testing) inspection method is not an FAA approved method of testing reflects a misunderstanding of the types of inspections that are recognized and approved by the FAA.

Each of the first three listed methods—visual inspection, NDT inspection methods, and the combination of IA visual and NDT inspection—are recognized practices within the framework of aircraft maintenance and safety checks. Visual inspections are fundamental, allowing an inspector to visually assess the integrity and condition of aircraft surfaces and parts. NDT methods, which include techniques such as ultrasonic testing, magnetic particle testing, and dye penetrant testing, are essential in ensuring the structural integrity of critical components without causing damage.

In contrast, destructive testing refers to methods where the test specimen is subjected to conditions that lead to failure or damage, making it unsuitable for further use. While destructive testing can provide valuable insight into material properties, it is typically not compatible with aircraft inspection protocols. The focus of FAA approved testing methods is often on maintaining the aircraft's usability and safety.

Thus, recognizing a combination of visual inspection performed by an IA along with NDT as an approved method would typically be valid, making the assertion that it is not approved incorrect.