Aerospace NDT Certification Requirements: Level I, Level II and the Level III Behind Them

Which Edition of SNT-TC-1A Does Your Purchase Order Name?

The current ASNT document is SNT-TC-1A (2024), with an addendum that took effect in May 2025. The 2024 edition adds the ASNT 9712 Program to the recognised examination routes, restricts eye drops used to improve vision, tells employers to assess whether externally referenced examinations meet their requirements, and expects the proctors of written examinations to be trained. ASNT recommends using it with ANSI/ASNT CP-105 (2024), the topical outlines that training content is traced to.

Aerospace purchase orders and process specifications do not always cite the latest edition, so read what yours names before building a training plan or revising the written practice. A firm that audits itself against a different edition from the one its purchase order names collects a finding before anyone looks at a technician. The full requirement set, documents and common findings are on our SNT-TC-1A compliance page, and the aerospace view is collected in the aerospace NDT compliance hub.

Level I and Level II Hours Are Method-Specific

SNT-TC-1A's recommended minimums are not uniform across methods, and a hiring plan that treats them as one number fails in both directions. Direct entry to Level II in penetrant is 12 training hours and 210 hours of experience in the method. Magnetic particle is 20 and 280. Visual is 24 and 210. Ultrasonic, radiography and eddy current each sit at 80 training hours and 840 hours of experience. Level II figures are in addition to Level I, so a newcomer going straight to Level II owes the sum of both.

Experience means hours worked in the method, documented in experience letters and logs. Training hours, practical course hours and simulator time do not count, however realistic the simulator. The written practice may also set a minimum of total NDT experience across all methods, and an aerospace written practice should say exactly how that total is accounted. Our SNT-TC-1A eligibility checker compares a candidate's documented hours with the recommended minimums, and the training hours guide breaks them down by technique.

The aerospace question is which of these figures the customer accepts as written. The surface methods carry the lowest recommended hours and are often where fracture-critical work lives: fluorescent penetrant on rotating engine parts, magnetic particle on landing gear. Where a purchase order or prime process specification asks for more, the written practice has to carry the higher figure for that method, and the training record has to prove it was delivered.

Recommended in the Standard, Binding in Your Written Practice

SNT-TC-1A is a recommended practice, not law. It becomes binding when a code, customer or regulator invokes it, and for an aerospace supplier that is typically the prime's purchase order. The instrument that gives it force inside the company is the written practice: the employer's own document covering training, examination, experience, vision and recertification for every method and level it certifies, approved by its NDT Level III and retained on file.

Customers then audit the firm against its own written practice rather than against SNT-TC-1A directly. That cuts both ways. A written practice that copies the recommended tables without making the choices the employer is supposed to make is the most common finding against the document. One that promises more hours or a tighter interval than the shop actually delivers turns every certification file into a nonconformance, because the auditor compares the file with your text, not with ASNT's.

This is why hour-for-hour equivalence arguments rarely help in aerospace audits. The auditor is confirming that the figure your written practice states was met, that the training content matched the method and traced to the CP-105 outlines, and that any outside training provider was assessed against the written practice before its certificates were accepted. Identical totals assembled from unassessed courses do not survive that check.

Examinations: General, Specific, Practical and the 80 Percent Composite

Each level needs a general examination on the principles of the method, a specific examination on the procedures, codes and equipment the person will use, and a practical examination on real specimens, administered by a Level III. SNT-TC-1A recommends a composite grade of at least 80 percent with no single examination below 70. A candidate can clear every part at 70 or 75 and still fail on composite, so training plans aimed at the per-part minimum produce failed certifications.

In no case is a certification examination administered by the candidate or by someone the candidate supervises. The question bank is approved by the NDT Level III and kept under control rather than reused without revision. The 2024 edition adds two points aerospace shops feel quickly: written-examination proctors are expected to be trained, and the employer must assess whether externally referenced examinations meet its requirements before relying on them.

Aerospace adds content, not a different structure. The specific examination should test the prime's process specification and the shop's own procedures and technique sheets. The practical should be run on specimens representative of the parts, alloys and discontinuities the technician will actually inspect, with a documented key. Weld coupons in carbon steel prove little about a technician who will sign off turbine discs or bolt holes in aluminium wing structure.

The Level III Behind the Programme

SNT-TC-1A requires the written practice to be approved by an NDT Level III, and aerospace programmes often call the person who carries that duty the Responsible Level III. In practice the role writes or approves the written practice, approves procedures and technique sheets, controls the examination question bank, administers or oversees examinations, and recommends certification. The employer's Level III is the signature an auditor traces back from every certificate.

Method scope is where organisations get it wrong. The Level III must be qualified in each method they sign for; a Level III in ultrasonics cannot sign for radiography, and a Level III in penetrant does not cover magnetic particle. Auditors ask for the Level III's qualification records: ASNT NDT Level III certificates, or the outside-agency agreement plus that person's credentials.

A firm with no Level III on staff can engage an outside agency Level III under a written agreement. That contracted Level III can write and approve the written practice, build and grade examinations and recommend certification; the employer still signs and issues the certificate. Atlantis provides ASNT Level III consulting for aerospace programmes on that basis in UT, RT, MT, PT and VT, supporting the employer's Level III role while the certification decision stays with the employer. The general service is described under outsourced ASNT Level III consulting.

Vision Records Are a Recurring Audit Finding

Near vision is examined natural or corrected, in at least one eye, reading a minimum of Jaeger Number 2 or an equivalent type and size letter at not less than 12 inches (30.5 cm). The written practice sets how often it is repeated, and the 2024 edition restricts eye drops used to improve vision. The record belongs in each person's certification file, dated and signed.

The second half is colour contrast. The examination has to show that the person can distinguish and differentiate contrast among the colours or shades of grey used in the method, as the written practice specifies. A fluorescent penetrant inspector reading indications under UV-A and a digital radiography interpreter reading greyscale are doing different visual tasks, and a generic screening that ignores the method is weak evidence.

Findings cluster in the same places. Vision records expired or missing, with no mechanism that stops the technician working. A colour record taken once at hire and never repeated when the written practice says it should be. A record that does not show who gave the examination. All three are file-keeping failures rather than technical ones, and all three are avoidable with a tracker keyed to each person's own examination date.

What an ASNT-Certified Technician Keeps When Moving to Aerospace

SNT-TC-1A does not produce a portable certificate. The employer certifies, and where the individual holds no third-party certification the credential is revoked on termination of employment. A technician arriving from a refinery or a fabrication shop arrives uncertified as far as the new aerospace employer's written practice is concerned.

What survives is documentation, and it is worth a great deal. Training certificates showing hours, syllabus and instructor. Experience letters and logs on company letterhead with dates, method and supervisor attestation. Prior examination results. The receiving Level III evaluates that record against the written practice for the specific method and credits what is verifiable. An ultrasonic technician with 840 documented hours in the method has already met the recommended direct-entry Level II experience figure on paper.

The gap is rarely total hours. It is content and specimens. Aerospace practical examinations belong on aerospace hardware with representative discontinuities in aerospace alloys and geometries, evaluated against the acceptance criteria in the prime's specification. Weld inspection experience on carbon steel pipe does not prepare a technician for bolt-hole eddy current or turbine blade penetrant, and the practical is where that shows. Our aerospace NDT training and ultrasonic testing training for aerospace are built around that gap.

Level III Qualification and the ASNT NDT Level III Certificate

ASNT NDT Level III eligibility depends on education and experience rather than a fixed number of method hours, and ASNT publishes those requirements. The ASNT NDT Level III certificate is the conventional basis for the employer's Level III, and auditors look for it in the Level III's qualification file alongside evidence for every method signed.

Holding the certificate does not by itself make a person the employer's Level III, or anyone's Responsible Level III. The employer designates the role, the written practice names the person, and the method scope has to match. A Level III who left the company and is still named in the current written practice is a finding on its own.

Techniques that sit on top of a method, such as phased array and TOFD, are set by the written practice and usually build on UT Level II. Atlantis offers ASNT Level III exam preparation for candidates working toward the role and phased array training for technicians adding the technique.

Recertification and the Interval Your Written Practice Sets

ASNT describes a recommended maximum interval of five years; the employer's written practice sets the actual interval. Recertification requires evidence of continued competence, either re-examination or documented continuing activity, plus current vision records. A written practice that states one interval and then recertifies on a different one is a finding regardless of which interval is better.

The years between are not idle. Aerospace customers and assessors read the file for evidence that the person stayed current: continuing work in the method, vision records within the interval the written practice sets, and any proficiency checks the customer requires. A file with a valid certificate and gaps in that evidence is still a nonconformance.

Certification also ends with employment. For contract technicians moving between aerospace employers, the receiving employer runs its own qualification and certification cycle each time, working from the technician's documented history. Building that history into a clean, auditable record is the most valuable thing an aerospace NDT technician can do for their own career.

Where SNT-TC-1A Sits Against Nadcap AC7114, AS9100 and Prime Specifications

Nadcap accreditation for NDT, administered by the Performance Review Institute, is the audit layer most aerospace suppliers actually experience. AC7114 is the audit criteria: a baseline covering the quality system, personnel and process control, plus method slash sheets for penetrant, magnetic particle, ultrasonic, radiography and eddy current. Nadcap does not replace the written practice; it verifies that the supplier's NDT special process, including personnel qualification, meets the requirements its customers impose. Assessors sample personnel files early, and each nonconformance is closed with root cause and corrective action before accreditation.

AS9100 asks the supplier to determine and evidence competence and to control documented information; for NDT, the written practice and the certification files are that evidence. FAA-certificated repair stations add 14 CFR Part 145, including the employee training programme required by §145.163, and the NDT qualification scheme has to sit consistently alongside it. Our Nadcap AC7114 audit readiness and aerospace Level III audit support pages cover the audit side in detail.

Above all of this sit the primes' own process specifications. Airframe and engine primes and their tier ones publish specifications that set personnel qualification requirements and then add more: approved procedures, specific reference standards, technique-level qualification and part-specific acceptance criteria. SNT-TC-1A is the baseline; the customer specification is the actual requirement. Read both before designing a training programme.

Building a Written Practice and Records System That Survives an Audit

Most aerospace NDT nonconformances found in audits are documentation failures, not technical ones. Hours logged in a spreadsheet nobody reconciles. Vision records filed by year rather than by person, so a lapse is invisible. Examination papers with no Level III approval behind the question bank. Training certificates that name a course but not the syllabus, instructor or hour count. Each is preventable and each is a finding.

The fix is treating personnel qualification as a controlled data problem: one record per person per method, carrying the training hours with their source, the running experience total, examination scores by part and composite, vision dates against the written-practice interval, recertification due dates and any technique limits. When those fields are queryable, an audit becomes an export instead of a fire drill.

Atlantis provides ASNT NDT Level III consulting for aerospace and aviation programmes: written practice development, procedures, technique sheets, examinations and preparation for Nadcap AC7114, customer and FAA Part 145 audits, with the option of acting as the employer's outside agency Level III in UT, RT, MT, PT and VT. We deliver ASNT SNT-TC-1A-based Level I and II method training for aerospace and aviation teams, and NDT inspection services for aerospace and aviation. Our NDT reporting software and ERP for NDT firms carry certification tracking, expiry alerts and calibration control. Quote on request: request a consultation.

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