NAS410: What Changed in the Current Revision

NAS410 is the National Aerospace Standard for qualifying and certifying nondestructive testing personnel. If you perform NDT on aircraft, engines, spacecraft or their support equipment, your employer almost certainly certifies you to it.

We first wrote about NAS410 in 2015, when Revision 4 was new. Two revisions have followed. This page now covers the current one, NAS410 Revision 6, and what it changes for technicians, Level 3s and the people who maintain a written practice.

The seven headline changes

AIA lists these as the significant changes from the previous revision:

1. An updated list of the NDT methods the standard covers in detail.
2. More terms and definitions.
3. Updated education requirements for Level 3.
4. Revised vision requirements, including a new vision-test option.
5. A new basic examination that every Level 3 candidate must pass.
6. Updated rules for reinstating a certification.
7. A new appendix giving a credit-based route to Level 3.

Here is what each one means in practice. This is our summary, in our own words; it is not a substitute for the standard, which you can buy from AIA.

1. A basic exam for every new Level 3

This is the change most programs will notice first. Before a candidate can sit the method exams for their first Level 3 certification, they must now pass a basic examination with three parts:

• closed-book questions on at least four NDT methods, including the ones the employer uses;
• closed-book questions on materials and manufacturing processes;
• open-book questions on the NAS410 / EN 4179 requirements themselves.

Each part has a minimum number of questions and needs a score of at least 80%. The basic exam is taken once per candidate, not once per method, and its score is not averaged into the certification exams. A current Level 3 from ASNT, ISO 9712 or a national aerospace NDT board can be offered as evidence of the basic exam, but the candidate still takes a supplemental exam on the NAS410 / EN 4179 requirements.

2. A credit-based route to Level 3

A new appendix lets a certified Level 2 qualify for Level 3 in the same method by building up documented, supervised Level 3-type work instead of meeting the time-based experience requirement. Points are earned in categories such as writing procedures and work instructions, training and supervising trainees, audits and technical control, and continuing education, with a minimum in each of the main categories. A candidate needs 36 points in total, and at least one year must pass before becoming eligible this way.

The route does not skip anything else: the candidate still takes every exam, and the points have to be recorded in the certification file. It is a good fit for capable Level 2s who are already doing Level 3 work under supervision.

3. Level 3 education and experience

The time-based route to Level 3 still ties experience to education. You must be a certified Level 2 in the method first, then work at Level 2 for:

• 4 years with no qualifying college study;
• 2 years after completing a two-year engineering or physical science program;
• 1 year with a three- to four-year engineering or physical science degree.

The wording of these requirements, and of the separate table for an employer's first Level 3 in a method the standard does not cover in detail, was updated in this revision. If your written practice paraphrases the old wording, compare it line by line.

4. Vision requirements

Near vision can now be checked with a Tumbling E test to ISO 18490:2015, as well as the familiar Snellen and Jaeger charts at set reading distances. The acuity must be met in at least one eye, natural or corrected, and simulated tests or distances are not allowed. Near vision is still tested every year and color perception at least every five years. After any condition or procedure that could affect vision, the Responsible Level 3 must be told and the person re-tested.

5. Reinstating a certification

The revision spells out what it takes to bring a certification back:

• Suspended (for example, an expired eye exam or a year without working in the method): reinstated once the cause is fixed and proficiency is verified, keeping the original certification date.
• Expired: reinstated only by passing the specific and practical exams.
• Revoked: reinstated only by passing the general, specific and practical exams, after the cause is fixed.

6. More definitions

The definitions section is larger. Among the terms now defined are the basic examination, automated equipment, and non-film radiography, which is described as including computed radiography, digital radiography, radioscopy and computed tomography. Definitions settle arguments during audits, so it is worth reading this section in full.

7. Methods covered

The standard gives detailed requirements for eddy current, penetrant, magnetic particle, radiographic, shearography, thermographic and ultrasonic testing. Other methods, such as acoustic emission, neutron radiography, leak testing and holography, fall under it when a customer or engineering authority invokes it, with hours set by comparison with a method of similar complexity.

What has not changed since Revision 4

• You must hold Level 2 in a method before certifying to Level 3 in it. The old "equivalent to Level 2" shortcut is still gone.
• Experience hours are recorded method by method. The same hours cannot be claimed for two methods at once.
• Radiography is still split into film and non-film, with higher minimums for people certified in both.
• Levels 1, 2 and 3 are recertified at least every five years, and anyone who processes or inspects product has an annual proficiency review.

For the current Level 1 and Level 2 hour minimums side by side with SNT-TC-1A, see our guide to NDT certification after your military career.

What to do now

1. Get the current revision and compare it with your written practice.
2. Add the basic exam to your Level 3 process, and decide how you will handle candidates who already hold an outside Level 3.
3. Decide whether you will offer the credit-based Level 3 route, and if so how points will be approved and recorded.
4. Update vision-test procedures and forms, including any Tumbling E option.
5. Rewrite your suspension, expiry, revocation and reinstatement section to match.
6. Brief your examiners and update your certification records to hold the new information.

Midgard Scientific provides Responsible Level 3 support, program development and audits for aerospace NDT programs. If you would like a second set of eyes on your update, contact us.