For an aerospace supplier, Nadcap accreditation for nondestructive testing (NDT) is often the difference between being on a prime contractor's approved list and not. It is also one of the most record-heavy audits an NDT shop will face. The auditor is not there to watch you inspect one part well. They are there to see whether your system would make every part come out right, and the evidence for that is almost entirely on paper.
This guide explains how the program works in outline, what the audit cycle looks like, how findings are handled, and the records you should have in order before the auditor arrives. It deliberately does not describe the audit checklist itself.
How Nadcap works
Nadcap is an industry-managed accreditation program administered by the Performance Review Institute (PRI). The distinctive part is who sits on the other side of the table. Instead of a single certification body deciding for itself, the prime contractors who subscribe to the program define the audit criteria for each special process, PRI schedules the audits and assigns qualified auditors, and a task group for each process reviews the audit reports and the supplier's responses. PRI's own summary of the cycle ends with the accreditation decision being made by the subscribers, and ongoing oversight through periodic audits.
NDT has its own task group, and the audit is scoped to the methods you actually hold accreditation for. A shop doing penetrant and magnetic particle inspection is audited against the general NDT criteria plus the criteria for those methods, not against radiography it does not perform. The same shop may also be audited against supplements that individual primes add for their own parts.
The audit cycle
PRI's public getting-started page lays out the path to a first accreditation, and it is worth reading in full. In outline:
- Register in eAuditNet, PRI's platform, where the audit criteria, your audit and your responses all live.
- Review the audit criteria for every method you want accredited, along with any customer supplements.
- Complete the self-audit. PRI lists it as a required step, and it is the single best preparation there is: answer every criterion against your own procedures and records, honestly, and fix what you find before anyone else finds it.
- Request a quote and schedule the audit. PRI's page puts the audit typically three to six months after scheduling, and the on-site audit itself at two to five days.
- Close the non-conformances. Each finding becomes a non-conformance report (NCR) that you answer in eAuditNet. PRI's page estimates one to three months for NCR closure, varying with the findings.
- Task group review and decision, after which the accreditation is granted and you move onto the reaccreditation cycle.
PRI describes a first accreditation as taking roughly six to twelve months end to end, and reaccreditation audits as typically every 12 to 24 months after that. Where you fall in that range depends on your record.
PRI also offers a pre-assessment: a voluntary on-site review by a Nadcap auditor ahead of the real audit. PRI is clear that its results are for your own preparation and play no part in the accreditation decision. It can be worth the cost for a first audit or a new method; it is no substitute for the self-audit.
Findings and the corrective-action clock
An NCR is not a verdict. It is the start of a structured exchange. For each one you are expected to show that you understand what went wrong and why, that you have dealt with the immediate problem (including any product that may have been affected), and that you have changed the system so it cannot happen again. A PRI staff engineer reviews the responses and may send them back for more; the task group gives the final review.
Every round of that exchange runs against a deadline set in PRI's procedures, and missing deadlines has consequences. PRI's own page warns that repeated delays or excessive non-conformances can lead to suspension or a failed audit. We do not quote the day counts here because they are PRI's to set; read them in eAuditNet at the start of the audit, and put the dates in your calendar the day the NCRs arrive.
The responses that pass first time tend to share a few habits:
- The root cause is a cause, not a restatement.“Technician did not follow the procedure” is where the investigation starts. Why was it possible not to follow it?
- Correction and corrective action are kept apart. Fixing this record is a correction. Changing the process so the next record cannot go wrong is the corrective action.
- The scope is checked. If one certification was out of date, the response shows that you looked at all of them.
- The evidence is attached: the revised procedure, the training record, the new log, not a promise of them.
Merit
Merit status is how a supplier with a consistently strong audit record earns a longer interval between audits. The criteria are set per task group and are built around audit performance, which in practice means few findings and responses that close cleanly and on time. Check the current criteria for the NDT task group in eAuditNet or with PRI rather than relying on what another supplier was told a few years ago.
The practical point: merit is lost in the NCR response as much as in the audit. A late or rejected response counts against you even when the underlying finding was minor.
The records auditors ask to see
An NDT audit moves between the shop floor and the files, and most of the time is spent in the files. Have these ready and retrievable without hunting.
Personnel
For aerospace NDT, personnel are certified to your written practice under NAS410, or its European twin, and the auditor will trace a sample of names from the shop floor back to the records. NAS410 Revision 6 sets the minimum personnel record in section 8.2.1: the method and level held, the latest exams and scores, the dates of the current certification and any suspension, training and experience history, education where it was used, the current vision and color results, the name and signature of whoever authorised the certification, and the most recent annual proficiency review.
Section 8.3.2 is the one to check before the audit: a certification is suspended when the vision exam or the annual proficiency review has expired, among other triggers, even if the certification itself has years left. An expired eye exam on a technician who signed yesterday's acceptance is a finding that reaches back into product. See the NAS410 guide for the full picture.
- The current written practice, approved as your practice requires.
- Who your Responsible Level 3 is, and evidence of their own certification.
- Each technician's file, complete to section 8.2.1, including outside agencies' certificates you relied on.
- Current vision exams and annual proficiency reviews for everyone who inspects.
Procedures and technique
Expect the auditor to compare your procedures and technique sheets with the specifications your customers invoke, and then compare what the technician does with your procedure. Keep the approved revision of each procedure, the record of who approved it, and the customer specification revision it was written to. When a specification revises, the auditor will want to know you noticed. The standard revisions guide covers how.
Equipment calibration
Every instrument, meter and gauge that makes a measurement the inspection depends on needs a calibration record, a due date that has not passed, and traceability to a recognised standard. Auditors routinely pick an item off the shelf and ask for its certificate, so the label on the gauge and the record in the file need to agree. When something is found out of tolerance, they will want to see what you did about the work it touched. More in the calibration guide.
Process control checks
The daily, weekly and periodic checks that prove a penetrant line or magnetic particle bench is working, set out in the process specifications your customers invoke, such as ASTM E1417 for penetrant and ASTM E1444 for magnetic particle, are some of the most heavily sampled records in an NDT audit. Auditors look for three things: that each check was done at its frequency, that the reading was within the limit, and that a failed check stopped production and led somewhere. A log with a gap on a working day, or a failing reading marked as a pass, is a finding waiting to happen.
The quality system around it
Internal audits, the corrective-action register, management review, supplier control and training records sit around the NDT-specific files. They are covered in the QMS guide. For Nadcap, the one to watch is closure: an open corrective action from your own internal audit, long past its due date, tells an auditor more about your system than any procedure does.
How TRACE handles it
TRACE keeps the records; it does not audit or accredit you, and only the Nadcap task group can make that decision. Nadcap accreditation tracking is part of the QMS module: accreditation status and PRI details, audits recorded item by item against your own checklists, findings worked from Open to Closed, and an exportable completed checklist. The checklist library starts empty on purpose. You import the checklists you already hold through eAuditNet, and TRACE never ships PRI's text. Each audit finding carries its root cause and corrective action, and can also be entered on the QMS corrective-action register, with correction and an effectiveness check, beside findings from other sources.
Tool Control holds the equipment register and calibration certificates, and a library of process control checks, each naming its governing standard, logged from the line and printed as a process-control log for the auditor. A failed check opens an out-of-tolerance event that lists the jobs and reports the gauge touched. Certifications and their due dates sit on each technician's record, vision exams too with the People module, with reminders before they lapse, and an auditor can be given a read-only login that ends on a date you set.
Frequently asked questions
Who decides whether a supplier gets Nadcap accreditation?
Not the auditor, and not PRI on its own. PRI schedules the audit and assigns a qualified auditor, the auditor reports what was found, and the task group for the process reviews the report and the supplier's responses. PRI describes the program as industry-managed, with the accreditation decision made by the subscribing prime contractors rather than by an independent certification body.
How often is a Nadcap NDT audit?
PRI's public getting-started page describes periodic reaccreditation audits as typically every 12 to 24 months. A new supplier starts on the shorter interval; a supplier with a strong audit record can earn merit status, which lengthens the interval. The criteria are set per task group, so check the current ones in eAuditNet or with PRI.
Does TRACE include the Nadcap NDT checklist?
No. The Nadcap checklists are PRI's copyrighted documents, and your firm reaches them through its own eAuditNet access. TRACE's Nadcap checklist library starts empty on purpose: you import the copies you are licensed to hold, and the audit runner, the PDF export and the optional AI pre-assessment work against those.
What personnel records does a Nadcap NDT auditor ask for?
Expect to show that each person doing NDT is certified to your written practice under NAS410 (or the equivalent your customers require): the written practice itself, training and experience history, the latest exams, a current vision exam, a current annual proficiency review, and the certification signed by the person your practice authorises. NAS410 Revision 6 lists the minimum personnel record in section 8.2.1.
Is a pre-assessment audit required?
No. PRI describes a pre-assessment as a voluntary on-site review by a Nadcap auditor before the real audit, and says its results are for the supplier's own preparation and are not part of the accreditation decision. The self-audit against the audit criteria is a different thing, and PRI lists it as a required step.
Checked against
- PRI public web pages on the Nadcap program, getting started with accreditation, and pre-assessment audits (p-r-i.org), read 28 September 2026
- NAS410 Revision 6, Aerospace Industries Association, revision date 1 December 2025 (sections 8.2, 8.3 and 8.6)
This guide summarises the documents above in our own words to help you find your way around them. It is not a substitute for them: requirements change between editions and contracts add their own, so check every figure against your own licensed copy and your written practice before you rely on it.
Named for reference only. TRACE is an independent product: it is not affiliated with, endorsed by, sponsored by or accredited by the Performance Review Institute (PRI), which administers Nadcap, Nadcap, the Aerospace Industries Association (publisher of NAS410) or ASTM International, or by any other organization whose standards or programs it describes. Their names and marks are their own.