For the aircraft maintenance, repair, and overhaul (MRO) sector, few diagnostic tools are as valuable and wide-ranging as nondestructive testing (NDT). Whether it is through the use of magnetically induced eddy currents, low viscosity fluorescent penetrants, magnetic particles, X-rays, or ultrasonic waves, the goal of these NDT methods are the same; namely to discover problems in aircraft parts and assemblies before they become serious, without causing damage to the aircraft being inspected.
Not surprisingly, the right to conduct NDT procedures isn’t just given; it has to be earned. Still, for those technicians and engineers who attain this certification, the rewards can be substantial.
“NDT inspectors are the people who ultimately make the ‘Accept/Reject’ decision on which parts are good enough to be attached to an airframe,” explains Steve Gaylord, chairman of the Aerospace Industries Association (AIA) National Aerospace Nondestructive Test Work Group, and manager of supplier quality at Eaton Aerospace.
“They get to make some of the final product-quality decisions that matter most to everyone.” Add the levels of financial compensation possible in the upper echelons, plus the fact that “there’s a dire need for qualified NDT personnel” across the entire aerospace industry, and it’s clear that being NDT-certified can be a wise career choice.
NAS 410: THE STANDARD THAT MATTERS
In the aircraft MRO sector, there are a number of NDT standards or recommended practices that can be adhered to. However, the de facto aerospace industry standard is NAS 410. Short for “National Aerospace Standard 410, Certification & Qualification of Nondestructive Test Personnel,” NAS 410 is the civilian derivation of the MIL-STD-410 NDT standard. The AIA is responsible for maintaining NAS-410 and other NDT-related standards.
“NAS 410 is the contractual standard that binds MROs, as maintained by the AIA,” Gaylord says. “However, it is the task of each aerospace company to establish its own NDT programs compliant with NAS 410 and any requirements laid down by equipment manufacturers.
“The AIA doesn’t conduct NDT certification education and testing,” he adds, “that’s the employer’s job.” This said, only a toplevel NAS 410 expert — known as an NAS 410-compliant Level 3 — has the ultimate authority to devise and oversee a given company’s NDT programs.
LEVELS OF NDT CERTIFICATION
Every level of NDT certification requires a successful blend of three elements: classroom education, on-the-job experience, and formal testing. However, this is where the similarities end, because the requirements for an NAS 410 Level 1 NDT are far less than a Level 3. Moreover, although a Level 1 can be certified for a narrow range of procedures directly relevant to their technician job descriptions, Level 2s and 3s are typically trained to use a broad range of NDT methods.
Let’s start at the beginning. An NAS 410 trainee is the entry-level NDT position, operating under the direct supervision of a Level 2 or Level 3. During this process, the trainee must take a minimum of 16 hours of classroom training (and pass tests) at his or her place of employment, plus gain 130 hours of practical, hands-on experience, and then be tested for knowledge and technique. In certain cases, an NDT technician can be certified as a “Level 1 Limited,” meaning that they can execute certain procedures themselves. In most cases, a general Level 1 has more authority than a Level 1 Limited, and when approved by a Level 3, their accept/reject assessments must be based solely on test results.
Airframe Technology Nondestructive Testing Paths to NDT Certification By Joe Escobar August 2004 Nondestructive testing (NDT) is widely used in aviation. It is...
One of the most diverse nondestructive testing (NDT) methods.