1. Ensuring Quality Control: NDT Level 3 personnel are responsible for ensuring that the NDT procedures are performed correctly and that the results are accurate. They are responsible for the overall quality control of the NDT process, and their expertise is critical in ensuring that the components and structures being tested meet the required standards.
2. Safety: NDT Level 3 personnel are also responsible for ensuring the safety of the aerospace structures and components by identifying issues early on the process, they can prevent catastrophic failures and ensure that the aircraft is safe to operate.
3. Cost Savings: NDT Level 3 personnel can also help save costs by identifying the proper inspection method and techniques and by detecting and addressing issues before they become major problems. They can prevent costly repairs and reduce the risk of downtime. This can ultimately save the aerospace companies a significant amount of money in the long run.
4. Compliance: The aerospace industry is highly regulated, and NDT Level 3 play a critical role in ensuring that the industry meets all the necessary regulations and standards. They are responsible for ensuring that the NDT procedures comply with all applicable regulations and that the results are accurate and reliable.

Overall, having NDT Level 3 personnel in the aerospace industry is crucial for ensuring quality.