Aerospace NDT (SNT-TC-1A) Audit Preparation for Inspection Companies

An aerospace NDT audit runs in six stages, from confirming which requirements apply (the prime's flow-down, the AC7114 base checklist and the method slash checklists) to the Nadcap Task Group vote. Auditors sample finished jobs back to the written practice, certification files and calibration records, so preparation means reconciling records to jobs rather than rewriting manuals.

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. What separates firms that clear an audit from firms that collect findings is not the quality of the documentation but whether it describes what actually happens. The finding recorded most often is: Self-audit not performed, or performed without all applicable job audits, consistently among the most-cited AC7114 nonconformances

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.

Aerospace NDT (SNT-TC-1A) audit — stages and what each tests
Stage	What happens	What it tests
Stage 1	Confirm which requirements apply: the prime's flow-down, the AC7114 base checklist and the slash checklists for the methods and techniques.	Where the paperwork is tested against itself
Stage 2	Apply through PRI's eAuditNet and complete the self-audit against those checklists, including all applicable job audits; send the required package.	Where the paperwork is tested against practice
Stage 3	On-site audit covering customer and procurement requirements, internal NDT audits, the written practice and certification files, examinations and vision testing,.	Where the paperwork is tested against practice
Stage 4	Auditor raises nonconformance reports; the supplier responds with root cause and corrective action, reviewed by PRI staff engineers	Where the paperwork is tested against practice
Stage 5	The Nadcap NDT Task Group votes on accreditation	Where the paperwork is tested against practice
Stage 6	First reaccreditation audit within twelve months of the initial audit; the Supplier Merit Program can extend later intervals to 18.	Where the paperwork is tested against practice
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.	Tracked from the dates the regime sets, not the last audit

How long does Aerospace NDT (SNT-TC-1A) audit preparation take?

Document work — the written practice, procedures and quality manual — takes weeks. What cannot be compressed is documented experience and records history: on-the-job hours accrue in real time, and calibration and certification history cannot be back-filled. Firms that start when the audit is scheduled rather than announced clear it without findings.

What does an Aerospace NDT (SNT-TC-1A) auditor look at first?

Records, not manuals. A manual states intent; records show practice. The usual opening move is to take a completed job and trace it back to the technician's certification, the instrument's calibration, the approved procedure and the report — and see whether all four reconcile.

What are the most common Aerospace NDT (SNT-TC-1A) findings?

Self-audit not performed, or performed without all applicable job audits, consistently among the most-cited AC7114 nonconformances, Required pre-audit package not sent to the auditor 30 days before the audit, Corrective actions from the previous Nadcap audit no longer implemented at the following audit, Calibration requirements not flowed down to subcontracted calibration or subcontracted NDT services. Almost all of them are evidence problems rather than capability problems: the work was done correctly and the proof was not kept, or was kept somewhere the firm could not retrieve during the audit.

Can a consultant attend the Aerospace NDT (SNT-TC-1A) audit?

Yes, and it changes the outcome. Someone who has sat through the same audit at other firms answers in the auditor's own terms, produces the right record without a search, and stops a clarification turning into a finding. The firm still owns every answer — the consultant does not speak for it.

What happens after an Aerospace NDT (SNT-TC-1A) finding?

A corrective action with a deadline, and evidence of closure at the next audit. Repeat findings are treated far more seriously than first ones, because they show the corrective-action system itself is not working.

Does Aerospace NDT (SNT-TC-1A) require a pre-audit or gap assessment?

Not as a requirement, but the arithmetic favours it: a gap assessment finds the same evidence problems the auditor would, without the finding attached, and while there is still time to fix them. Firms entering their first Aerospace NDT (SNT-TC-1A) audit blind typically collect findings that a sampling exercise would have caught.

What the auditor asks to see

Written practice for the training, qualification and certification of NDT personnel, built on ASNT SNT-TC-1A (2024), approved by the employer's NDT Level III and carrying the customer's aerospace flow-down requirements
Written designation of the Level III responsible for the programme, with that person's ASNT NDT Level III certificates or the outside-agency agreement and credentials
Individual certification files: training hours, documented experience, General, Specific and Practical examination results on representative aerospace parts, and current vision examination results
NDT procedures and technique sheets for each method, approved by a Level III certified in that method and traceable to the prime specification and to ASTM E1417, E1444 or E2375 as applicable
Records retention schedule covering certification files, examination papers and job records for the period the customer contract and the written practice require
Customer and procurement requirement flow-down records showing which prime specifications apply to which part numbers and jobs
Internal NDT audit records, plus evidence that corrective actions from the previous Nadcap or customer audit remain implemented
Equipment calibration, system performance check and process control records, including calibration requirements flowed down to subcontractors
The completed AC7114 self-audit package, including all applicable job audits, sent to the auditor before a Nadcap audit

Findings to close before the audit

Self-audit not performed, or performed without all applicable job audits, consistently among the most-cited AC7114 nonconformances
Required pre-audit package not sent to the auditor 30 days before the audit
Corrective actions from the previous Nadcap audit no longer implemented at the following audit
Calibration requirements not flowed down to subcontracted calibration or subcontracted NDT services
Written procedure and observed practice disagree during a job audit: the technique the operator ran is not the technique the procedure specifies
Experience carried in from a prior employer accepted without the Level III's documented evaluation
Written practice not re-approved by the current Level III after a personnel change
Process timing steps missed during a job audit; PRI's published lists cite eddy current step-one timing among the recurring job-audit nonconformances
A customer flow-down requirement, such as a practical examination on the customer's own parts, missing from the written practice, so certifications meet SNT-TC-1A but not the purchase order

Get audit-ready, and stay that way

Auditors read the documents before they watch the work. Atlantis prepares the evidence pack and the Level III documentation behind it, trains the technicians, and Atlantis ERP keeps the records current between audits.

Speak to an ASNT NDT Level III

Discuss your inspection requirements with Atlantis NDT. Include the asset, method, location and documents you need reviewed.