14 CFR Part 145 Repair Station NDT: Rating, Manuals, Personnel

The rating is 145.61(b)(9), and the opspec has to name your specification

Part 145 ratings split into class ratings and limited ratings. Section 145.61(a) allows a limited rating where a repair station performs only specialized maintenance requiring equipment and skills not ordinarily performed under other repair station ratings. Nondestructive inspection, testing, and processing sits at 145.61(b)(9) as its own limited rating. A shop that holds an airframe class rating and quietly runs a penetrant line beside it is not covered by that class rating. The NDT work needs the NDT rating, listed on the certificate and reflected in the operations specifications.

Section 145.61(c) is the clause first-time applicants miss. For a limited rating for specialized services, the operations specifications of the repair station must contain the specification used to perform the specialized service. That means naming a real controlled document: an OEM process specification, a customer specification, AMS 2644 for penetrant materials, ASTM E1417 for the penetrant process, or the prime's own process spec. The FAA does not accept the phrase industry standard practice in an operations specification. It accepts a document number and a revision, and it will check that your procedures match it.

FAA AC 25-29 confirms the link. Its Appendix 1 lists related CFR regulations, and the only Part 145 citation on that list is section 145.61, Limited Ratings. If you build an NDI organisation to AC 25-29 while holding a Part 145 certificate, the rating you are building toward is the 145.61(b)(9) limited rating. Shops working across airframe, engine and component programmes usually pair that scope decision with the wider programme design covered in our aviation NDT consulting work at /consulting/aviation-ndt-consulting.

Repair station manual versus quality control manual: which one carries the NDT content

Section 145.207 requires the manual; 145.209 lists what goes in it. Eleven items: an organizational chart identifying management positions with areas of responsibility, duties and authority; procedures for maintaining and revising the rosters required by 145.161; a description of operations including housing, facilities, equipment and materials; capability list procedures; procedures for revising the training program and submitting revisions for approval; procedures for work performed at another location under 145.203; contract maintenance procedures; a description of the records system; manual revision procedures; and the system used to identify and control manual sections. None of those say NDT. The NDT content is what you put into each slot.

Section 145.211 is the quality control system, and 145.211(c)(1) lists nine procedures the quality control manual must describe. Two of them decide your NDT audit: subparagraph (iv), establishing and maintaining proficiency of inspection personnel, and subparagraph (viii), calibrating measuring and test equipment used in maintaining articles, including the intervals at which the equipment will be calibrated. AC 145-9A section 5.8 expands subparagraph (iv) and names sections 145.155, 145.157, 145.161 and 145.211 as its governing references.

AC 145-9A section 5.5.3 flags mobile NDT explicitly. Recurring work away from the fixed location, which the AC illustrates with fuel cell repair, nondestructive testing and mobile field services, requires procedures under 145.203(b) and OpSpec D100. Most NDT shops are mobile at least part of the time, and this is exactly where a first-time applicant's manual runs thin: work order generation from the fixed location, field-to-base communication of voice and data, and control of equipment and standards on the road all have to be written down.

Inspector proficiency: what 145.155 and 145.211(c)(1)(iv) actually mean

Section 145.155(a) requires the repair station to ensure persons performing inspections are thoroughly familiar with the applicable regulations and with the inspection methods, techniques, practices, aids, equipment and tools used to determine the airworthiness of the article, and proficient in using the various types of inspection equipment and visual inspection aids appropriate to that article. Section 145.155(b) requires inspectors to understand, read and write English. Those are competence statements. They are not certificates, and a Level II card on its own does not satisfy them.

AC 145-9A section 5.8.3 explains how the FAA expects you to make competence auditable. The manual should say how initial qualification is established, whether by testing, previous experience or training; the minimum amount of experience required before an inspector can be listed on the roster; and who, by job title, makes that determination. Section 5.8.4 adds the sentence that ties Part 145 to the NDT world: inspectors performing NDT may need to meet the qualification requirements of other industry standards, such as eye exams.

That sentence is the hinge of the whole page. Part 145 never defines what an NDT Level II is. NAS 410 or SNT-TC-1A defines it, through a written practice that a Level III owns and signs. Getting the written practice right first is what makes the proficiency procedure in the quality control manual short, specific and defensible, which is the sequence we work in at /consulting/written-practice-development. Writing the QCM procedure first and back-filling a written practice produces two documents that disagree, and an inspector reads both.

The training program under 145.163 and where NDT lands in it

Section 145.163 requires a certificated repair station to have and use an employee training program approved by the FAA, containing initial and recurrent components, that ensures each person handling maintenance, preventive maintenance, alterations and inspections is capable of performing the assigned task. Applicants submit the program with the certificate application. Revisions go to the responsible Flight Standards office. Records are kept a minimum of two years in a form acceptable to the FAA. Approved is the operative word: the repair station manual and quality control manual are accepted, and the training program is approved.

AC 145-10, dated 7/8/05, divides training into indoctrination, technical training, recurrent technical training and specialized technical training. Paragraph 304 tells the repair station to identify job assignments requiring special skills or complexity, and names special inspection or test techniques among its examples alongside flame and plasma spray, complex welding and complex assembly. NDT sits there. The AC then asks the repair station to address initial and recurrent training requirements for every task it decides needs specialized training.

The recurring failure is a training program that maps cleanly onto airframe and powerplant tasks and treats NDT as a single line item. Method-by-method classroom hours, on-the-job training, recurrent intervals and the recertification clock all belong in the approved program, and every one of them has to agree with the written practice. Where the two disagree, the FAA inspector has found a finding without leaving the conference room, because both documents are in front of them.

Which NDT standards the FAA actually accepts

On 15 June 2007 the FAA issued a memorandum from AIR-200 and AFS-300 titled Qualification Standards for Nondestructive Testing, addressed to all Manufacturing Inspection Office managers, all Manufacturing Inspection District and Satellite Offices, and all Flight Standards District Offices. It is information only and not national policy, and it opens with the fact that governs everything downstream: in the United States there is no national certification requirement or standard for aviation NDT personnel.

The memo lists the standards acceptable to the FAA. MIL-STD-410E, rescinded by the Department of Defense but still considered acceptable. ATA Specification 105, Guidelines for Training and Qualifying Personnel in Nondestructive Testing Methods. AIA-NAS-410, which superseded MIL-STD-410E. And SNT-TC-1A, described as a document providing guidelines for employers to establish in-house certification programs. EN 4179 is treated as acceptable because it is technically equivalent to NAS 410. AC 65-31B paragraph 6 repeats the list and adds CAN/CGSB-48.9712 and ISO 9712.

For airframe, engine and component work the practical answer is NAS 410, because that is what OEM process specifications and prime contracts call out. Our page on NAS 410 certification requirements at /nas-410-certification-requirements sets out the levels, hours and examination structure, and /consulting/nas-410-responsible-level-3 covers the Responsible Level 3 role NAS 410 creates, which has no direct equivalent in SNT-TC-1A and is the single most common gap when a Part 145 shop moves from general aviation into prime-contract work.

Recurrent training, recertification intervals, and the six-month trap

AC 65-31B paragraph 11 sets the clocks. Level I Special personnel are recertified for each certification held at intervals not exceeding one year. Levels I and II are recertified at intervals not exceeding three years. Level III personnel are recertified at five-year intervals. Requalification examinations consist of a demonstration of proficiency in the procedure for which the applicant is being examined, which means a practical, not a multiple-choice refresher.

Vision runs on its own clock. AC 65-31B paragraph 10 requires near vision in at least one eye, corrected or uncorrected, sufficient to read a Snellen equivalent of 20/25 or Jaeger #1, examined on a periodic basis not exceeding one year. Colour perception is tested once, usually at the initial vision examination, and the responsible Level III examiner evaluates and approves in writing any limitation in colour perception before certification.

Three conditions force requalification regardless of the calendar: demonstrated unsatisfactory performance; inactivity in the method for a six-month period, or a shorter interval set by the organisation's written program; and an expired vision examination. The six-month inactivity rule is what catches small shops with one radiographer and seasonal work. AC 25-29 separately sets recurrent training at a minimum of every three years, documented by a qualified instructor. Recurrent training and recertification are two obligations, and audits routinely find shops that performed one and recorded the other. Exam administration and proctoring is where an outside Level 3 usually earns their fee, which is the work described at /consulting/ndt-level-3-exam-oversight.

AC 25-29 and the five elements of an NDI organisation

AC 25-29, Development of a Nondestructive Inspection Program/Organization, dated 9/20/13 and initiated by AFS-300, describes five elements: documentation, organisation, environment, calibration and training. The AC states that it is neither mandatory nor regulatory and describes an acceptable means, not the only means. It is nonetheless the closest thing the FAA has published to a specification for an NDT shop, and inspectors read it before they walk your floor.

On organisation, AC 25-29 asks that the individual in charge of the NDI organisation meet, at minimum, the requirements for Level II qualification in the methods used, per an industry-accepted standard. It asks for a register that records the date of the inspection, the identification of the inspected aircraft or component with associated task card reference, the inspection method carried out and the reference of the tool used, the identification of the person who performed the inspection, and the result or a reference to the inspection report.

It then asks for four procedures that shops rarely write until someone asks. Procedures for shift changes so inspection item status is communicated and no step is lost. Procedures for inspection override authority, exercised only by individuals whose qualifications meet or exceed those of the original inspector. Procedures detailing when, how and by whom vision examinations are accomplished. And procedures ensuring that outsourced vendors accomplish inspections in accordance with the certificate holder's programme.

The method-specific sections are where audits get granular. Bath concentration measured and documented and suspension checked for contamination for magnetic particle. Dwell times, dry times and temperatures per the process specification, plus test panels to verify system performance, for penetrant. Reference standards of the same material as the part, probe design and frequency, scanning speed and direction for eddy current. AC 25-29 states that records of all process control checks must be retained, and those records are the first thing a customer quality audit asks to see.

The questions an FAA inspector actually asks

AC 145-9A section 5.8.7 prints the questions, offered as a guide to help initiate the procedures in the quality control manual. How does the repair station establish minimum qualifications for inspection personnel, and what is the title of the person making this determination? How will the inspector maintain proficiency, and what methods are used? Do the records of training indicate the method, length, instructor and dates, and are they current?

It continues. Do the employment records of the inspectors describe any previous experience? Is the necessary current technical data available and accessible for the inspectors? What is the title of the person responsible for ensuring that inspectors maintain proficiency? Are the inspectors listed on the roster? Do the inspectors read, write and understand English? Are persons performing required inspection item inspections and approvals for return to service certificated under Part 65 if in the United States? And, in the AC's own words: will the inspectors require any special training, such as NDT, and who will be responsible.

Not one of those questions asks to see a certificate. Every one asks for a documented system that produced the certificate and keeps producing it. A repair station that hands over a folder of Level II cards and cannot immediately produce the written practice, the general and specific examination records, the practical demonstrations, the vision records and the matching roster entry has answered a question nobody asked.

Where an outsourced Level III fits

AC 65-31B paragraph 9b is unambiguous: at the option of the organization and as provided in their written practice, a qualified outside agency may be engaged to provide NDI training, qualification and testing. The FAA's own guidance sanctions the arrangement. What it requires is that the written practice describes it, that the records live with the repair station, and that the roster under 145.161 reflects who is actually qualified.

The Level III duties AC 65-31B assigns are precisely the ones a small repair station cannot justify staffing. Select the method and technique for a specific inspection. Select or design equipment and reference standards. Verify the adequacy of procedures. Hold general knowledge of all other NDI methods the organisation uses. Be capable of conducting or directing the training and examination of personnel. And the sentence that matters commercially: only individuals at Level III should have the authority to approve procedures for the methods for which they are qualified.

The consequence is direct. A shop with two Level II technicians and nobody at Level III cannot approve its own NDT procedures, cannot examine its own candidates, and cannot sign a written practice. That is not a paperwork inconvenience; it is a bar to holding the 145.61(b)(9) rating at all. An outsourced Level III makes the rating reachable on a headcount the workload supports. Shops that also chase prime-contractor special process approval usually run the same Level 3 across /consulting/nadcap-ac7114-audit-readiness and the broader programme scope at /consulting/aerospace-ndt-consulting, because the written practice, the procedures and the technician records are the same evidence in both audits.

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