Phased Array Ultrasonics (PAUT) Requirements Under Aerospace NDT (SNT-TC-1A)
Procedure qualification usually requires a demonstration on a representative flawed sample, and the scan plan forms part of the approved procedure rather than a field decision. In an aerospace programme the employer certifies the PAUT technician under its SNT-TC-1A written practice, a Level III certified in PAUT approves the procedure, and Nadcap audits the job against the method's AC7114 slash checklist.
An auditor examining PAUT asks for the phased array unit, wedges, encoders, and the calibration blocks used for wedge delay, sensitivity and TCG. For aerospace NDT the personnel standard is the employer's written practice. Built on ASNT SNT-TC-1A (2024), it qualifies Level I, Level II and Level III personnel through training, documented experience, General, Specific and Practical examinations and vision examinations, approved by an NDT Level III. Aerospace work adds what the customer flows down: prime process specifications, ASTM E1417, E1444 and E2375 technique requirements and practical examinations on representative parts. Nadcap AC7114 then audits whether the written practice, the certification files and the job records agree.
Source: ASNT Recommended Practice No. SNT-TC-1A (2024) with Addendum, ASNT standards listing (asnt.org), for personnel qualification, certification and the recommended recertification interval. PRI Nadcap programme material and AC7114 for the audit sequence, the 30-day pre-audit package, recurring nonconformances, the Responsible Level 3 questions (5.5.1 to 5.5.4) and the Supplier Merit Program 12/18/24-month intervals (p-r-i.org), plus Quality Magazine's Nadcap NDT audit perspective. 14 CFR Part 145 and FAA Advisory Circular 65-31B for repair-station NDI personnel and outside agencies. Research checked August 2026.
| Item | What applies | Why it matters |
|---|---|---|
| Regime | Aerospace NDT personnel qualification and certification under an employer written practice built on ASNT SNT-TC-1A, audited through customer flow-down, Nadcap AC7114 and FAA Part 145 | Enforced through customer flow-down, Nadcap AC7114 audits and, for repair stations, the FAA under Part 145 |
| Method | Phased Array Ultrasonics (PAUT) | Needs its own procedure and its own qualified personnel |
| Procedure approval | The employer's Level III, qualified in this method | The signature an auditor traces |
| Other methods in scope | PT, MT, UT, RT (film), RT-D / digital radiography, ET | Each needs separate qualification |
| Renewal | Personnel recertification follows the employer's written practice. ASNT describes a recommended maximum interval of five years between renewals, and an aerospace customer can set a shorter interval or extra practical re-examination through its flow-down. Vision examination records must be current on the day of work. The company-level cycle is set by Nadcap: the first reaccreditation audit falls within twelve months of the initial audit, after which the Supplier Merit Program can extend the interval to 18 or 24 months depending on audit performance. | Applies to the personnel certification behind this method |
Does Aerospace NDT (SNT-TC-1A) require a separate procedure for PAUT?
Yes. Every method in scope needs its own written procedure, approved by someone qualified in that method, describing technique, equipment, calibration, scanning or coverage, acceptance criteria and reporting. A single combined "NDT procedure" covering several methods is a finding under every regime that names procedures individually.
Who can approve a PAUT procedure under Aerospace NDT (SNT-TC-1A)?
A Level III qualified in PAUT. Because Aerospace NDT (SNT-TC-1A) accepts employer-based certification, that Level III may be contracted rather than employed — but their own qualification must cover PAUT, and an auditor will check that before accepting the signature.
What PAUT records does an Aerospace NDT (SNT-TC-1A) audit sample?
The approved procedure, the technician's PAUT certification on the date of work, and the equipment evidence — the phased array unit, wedges, encoders, and the calibration blocks used for wedge delay, sensitivity and TCG. The auditor works backwards from a finished job, so every item has to reconcile with the report and its stated acceptance criteria.
What is the most common PAUT finding at audit?
Data acquired outside the scan plan the procedure qualified, or encoder position not recorded. It is a records failure rather than a technique failure — the examination was performed correctly and the evidence supporting it cannot be produced, which under Aerospace NDT (SNT-TC-1A) is recorded the same way as not having done the work.
Can a technician certified elsewhere perform PAUT under Aerospace NDT (SNT-TC-1A)?
Not automatically. Employer-based certification ends when the holder leaves, so the new employer must certify them under its own written practice. Prior training and documented experience transfer as evidence; the certificate itself does not.
What equipment evidence does PAUT need under Aerospace NDT (SNT-TC-1A)?
Calibration status traceable to the day of use, covering the instrument and its accessories — probes, cables, blocks and reference standards for ultrasonics; sources and densitometers for radiography. An in-calibration instrument with an out-of-calibration reference block fails the same way as an uncalibrated one.
How do PAUT requirements differ from the other methods in Aerospace NDT (SNT-TC-1A)?
Scope, qualification and evidence are method-specific, so the differences are real rather than administrative. Aerospace NDT (SNT-TC-1A) also covers PT, MT, UT, RT (film), RT-D / digital radiography, and each carries its own procedure, its own personnel qualification and its own equipment evidence.
Personnel certification for PAUT
Employer-based. The employer certifies its own NDT personnel under a written practice built on ASNT SNT-TC-1A and approved by an NDT Level III, and names in writing the Level III responsible for the programme. Nadcap AC7114 calls that person the Responsible Level 3 and accepts an internal or an external (outside agency) Level III, provided documentation on file shows the Level III meets the customer's specified requirements. Aerospace customers add their own conditions through the purchase order, such as practical examinations on representative parts and prime process specifications, so the written practice has to carry them. Atlantis provides ASNT NDT Level III consulting for aerospace written practices, procedures, examinations and audit preparation, can act as the outside agency Level III in UT, RT, MT, PT and VT, and delivers ASNT SNT-TC-1A-based training and NDT inspection for aerospace and aviation work.
Related: the aerospace NDT compliance overview, ASNT Level III consulting for aerospace, aerospace written practice development, SNT-TC-1A-based aerospace NDT training, aerospace NDT inspection, Nadcap AC7114, the SNT-TC-1A overview.
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Atlantis writes the procedure to this requirement, qualifies and demonstrates it, carries out the examination and trains technicians in the method. Atlantis ERP keeps the approved revision in front of the crew.
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