How a Metalworking Company Can Enter U.S. Aircraft Parts Machining: Entry Routes, AS9100D and IA9100, FAA Part 21, First Article Inspection, Nadcap, Export Control, Hurdles

Why look at U.S. aircraft parts now

According to the Facts & Figures report released by the Aerospace Industries Association (AIA) in June 2026, U.S. aerospace and defense industry sales in 2025 totaled $988.6 billion, including $506 billion in direct output and about $483 billion in domestic supply chain activity. Exports were $172.7 billion (up 25% year over year), and the industry supports about 2.1 million jobs, 1.1 million of them in the supply chain^[1]. These are trade association figures covering commercial aviation and defense combined.

For data closer to the shop floor, the Bureau of Labor Statistics (BLS) industry productivity program publishes annual output and employment for aerospace product and parts manufacturing (NAICS 3364). Nominal output went from $218.4 billion in 2018 to $158.4 billion in 2021, a drop of about 27%, then recovered to $214.1 billion in 2025. Employment bottomed out at 483,000 in 2021 and stood at 576,000 in 2025^[2][3].

On the demand side, the FAA's FY2026–2046 forecast expects domestic passengers on U.S. airlines to grow 2.4% a year on average over the next 20 years, while pointing to supply chain constraints holding back aircraft manufacturers' deliveries as a factor that may persist for the next few years^[5]. The Commerce Department's SelectUSA lists MRO (maintenance, repair and overhaul), composites, metalworking, avionics, test equipment and coatings as strengths of the U.S. supply chain^[4].

On trade, the Commerce Department opened a Section 232 investigation (Trade Expansion Act) into imports of commercial aircraft, jet engines and parts in May 2025^[6], and Presidential Proclamation 11040 of July 9, 2026, while finding that imports threaten to impair national security, decided to hold off on tariffs for now and pursue negotiations with trading partners. It says tariffs or other additional measures remain possible if negotiations fail^[7]. This could be a tailwind for domestic parts makers, but the outlook is not settled.

Where to start: Tier 2 and 3, special processes, MRO and PMA

The “PMA” in Route C (Parts Manufacturer Approval) is one of the FAA's production approvals: a combined design and production approval for replacement and modification parts. It allows you to make and sell parts for installation on type-certificated aircraft, and approved parts can be looked up in the FAA's database (DRS)^[8][9]. To get a PMA, you must submit drawings, materials and processes, plus tests and computations showing airworthiness (or proof that the part is identical to the original design), and have a quality system meeting 14 CFR 21.137^[10]. Becoming a supplier to a PMA holder first is the realistic path.

How this relates to defense workAerospace and defense are grouped as a single industry, and AIA's figures cover both^[1]. The quality system (AS9100D, AS9102) is the same, but if you make military aircraft parts, ITAR registration, cybersecurity (CMMC), DFARS specialty metals restrictions and more come into play (covered later).

AS9100D first: how to get it, what it costs, and the move to IA9100

The aviation, space and defense quality management standard “9100” is ISO 9001 plus industry requirements, published in the U.S. by SAE as AS9100D (revised September 20, 2016). Its content is the same as Europe's EN 9100 and Japan's JIS Q 9100^[14][15]. In 2025, 1,792 initial 9100 certifications and 5,301 recertifications were issued worldwide^[16].

1. Solidify your ISO 9001 system: If your procedures, records, calibration, nonconformance handling and internal audits are already working, you can build AS9100D on top of them.
2. Build the added requirements into the system and run it: configuration management, special process control, key characteristics, counterfeit prevention, control of external providers, on-time delivery and quality performance, and so on. PRI recommends running the system for about six months before the certification audit^[24].
3. Create an OASIS account and choose a certification body: Under IAQG's procedure, the organization sets up a user account in OASIS, IAQG's database, then gets quotes from and contracts with an accredited certification body participating in the IAQG certification scheme (listed in OASIS). Audits follow ISO/IEC 17021-1, 9104/1 and 9101^[20]. ANAB, the U.S. accreditation body, is recognized by IAQG to accredit AS9100 certification bodies^[21].
4. Your certificate is listed in OASIS: Customers can check your certificate and audit results in OASIS, and responses to nonconformities are also handled in OASIS^[20].
5. Recertify every 3 years: Within the 3-year cycle there is a surveillance audit every year^[24].

AS9100D will become “IA9100”The next revision will be named IA9100 under IAQG's new numbering scheme^[18]. The underlying ISO 9001:2026 was published on September 16, 2026^[19], and IAQG's annual report released in April 2026 shows publication of the revised 9100 scheduled for Q1 2027 in its timeline^[16]. As of October 2026, we found no official announcement of a transition deadline in IAQG's news^[17]. Publication won't instantly invalidate current certificates; companies normally switch over at a regular audit during a transition period, so if you're just starting, go ahead with AS9100D.

FAA rules: do parts makers need approval?

Legal responsibility for the quality of aircraft parts rests with companies that hold an FAA production approval (airframe and engine manufacturers, PMA holders, etc.). There are three kinds of production approval: production certificate (PC), PMA and TSO authorization^[8]. 14 CFR 21.137 requires the holder's quality system to include procedures to ensure that products, parts and services from suppliers conform to the holder's requirements, plus, for nonconformities found after release, procedures for suppliers to report them to the holder^[12].

• The FAA does not approve suppliers: FAA Advisory Circular AC 21-43A says “the FAA does not approve suppliers,” but also that it may visit the facilities of the holder and the supplier alike to monitor supplier control^[13].
• Responsibility can't be delegated: The holder flows requirements down through all supplier tiers, is responsible for compliance, and cannot delegate its production approval responsibilities to suppliers^[13]. That's why audits are strict and purchase terms are detailed.
• Direct shipment only with authorization: Direct shipment from a supplier to the customer is allowed only when the holder authorizes it. The industry guidance is SAE ARP9114^[13].
• Record retention: The holder must keep quality records for at least 5 years, or 10 years for critical parts, as required by the rule^[12]. Your inspection records and material certs are part of them, and some customers require even longer retention.
• You can't just sell them as replacement parts: Replacement parts for type-certificated aircraft may only be produced under a production approval, as standard parts (bolts, nuts, etc.), by a repair station for use in its own repairs, or under similar exceptions; nothing else may be sold as a part eligible for installation^[11].

No making extras from the same drawing to sellIf you make extra parts from a customer's drawing without the customer's direction and sell them to third parties, they are not parts produced under a production approval. If you want to sell replacement parts yourself, the proper route is to get a PMA^[11][9].

First article inspection (AS9102) and the standards customers specify

The most labor-intensive part of aircraft parts work is first article inspection (FAI). It goes beyond measuring dimensions: you verify for every characteristic that the planned processes, materials and tooling produce parts to print, and record it on set forms. The standard is 9102; the latest edition is the 2023 revision, AS9102C . There are three forms^[25].

Changed the NC program? Redo FAIOn top of design changes and changes in manufacturing source, process, inspection method, tooling, material or manufacturing location, even when you change the NC program or transfer it to other media, you must redo FAI for the affected characteristics^[26]. FAI is also required for characteristics that may be affected when production has stopped for 2 years or more^[27]. Even “we switched machines and now it cuts faster” requires notifying the customer and doing FAI first.

Nadcap and special processes: does a machining-only shop need it?

Nadcap is the industry accreditation program for critical (special) processes, launched by major aerospace manufacturers in 1990 and run by the nonprofit Performance Review Institute (PRI). It covers 24 process areas, with more than 4,500 accredited suppliers and over 60 participating OEMs^[33]. Before it, a supplier could face 3–4 audits of the same process, one per OEM; Nadcap was created to consolidate them into one^[33].

Nadcap commodities are based on PRI's list^[34][33].

• Prerequisite: Use AS9100 as your quality system, or undergo a Nadcap quality system audit (AC7004)^[35].
• Timeline: First-time accreditation takes about 6–12 months (2–4 months of preparation, a 2–5 day on-site audit, 1–3 months to close out findings (NCRs), etc.). Audits are usually held 3–6 months after you request a date, and reaccreditation audits typically follow every 12–24 months^[35].
• Cost: There is no published fee schedule; you get a quote for each audit scope through PRI's system^[35]. For first-timers, the Supplier Support Committee offers free mentoring^[35].
• Separate from customer approval: Nadcap accreditation is not customer approval in itself; it is used as one part of the customer's approval process. You can get it even before you have aerospace customers^[24].
• Benefits: In PRI's survey, accredited suppliers saw customer audits fall by 40% on average, and 85% felt their quality had improved (a survey by the operator itself)^[36].

First steps for a machining shopIf you outsource heat treatment, surface treatment or NDT, use only subcontractors approved by your customer (holding Nadcap, etc.), flow the customer's requirements down in your purchase orders, and make sure the subcontractor's certs can go on FAI Form 2. If there are few accredited processors nearby, shipping farther adds lead time and freight cost, so check candidate subcontractors before you quote.

Export control and the added requirements for defense work

Export controls apply even to parts you sell only domestically, because showing technical data to foreign persons on your staff can count as an “export.”

• Deemed exports (EAR): Releasing controlled technology to a foreign person in the U.S. is deemed an export to that person's most recent country of citizenship or permanent residency^[40]. Many commercial aircraft parts fall under the lightly controlled ECCN 9A991 (anti-terrorism controls only), but technology for developing and producing engine hot-section parts (blades, vanes, combustors, etc.) is 9E003 and is controlled for national security reasons^[41]. The customer determines the classification of each item, so confirm it when you receive the drawings.
• Deemed exports (ITAR): Releasing military technical data to a foreign person in the U.S. is deemed an export to every country in which that person holds citizenship or permanent residency^[39].
• ITAR registration: U.S. businesses that manufactures defense articles must register with the State Department's Directorate of Defense Trade Controls (DDTC) even if they don't export. Even a single production run counts^[37]. The fee for a new registration is $3,000 a year.^[38].
• CMMC (cybersecurity): The DFARS rule making cybersecurity certification (CMMC) a condition of DoD contracts took effect on November 10, 2025^[42]. Requirements also flow down to subcontractors that handle controlled information such as drawings.
• DFARS specialty metals restrictions: Titanium alloys, nickel alloys, steels with alloying elements above set thresholds, and other specialty metals used in items for DoD must be melted in the U.S. or a qualifying country. Mill products such as bar and plate, as well as forgings and castings, are not exempt from this restriction^[43]. Make sure you can verify the melt country from mill certs.

If you employ foreign nationals, check firstBefore receiving drawings, ask the customer which controls apply, decide who may view them, and keep the drawing data on separate PCs or folders. If a license is needed, get it before showing them.

MEP Centers and state support

• MEP Centers: NIST's Manufacturing Extension Partnership (MEP) is a public-private partnership supporting small and medium-sized manufacturers. State-designated MEP Centers operate in all 50 states and Puerto Rico, with nearly 1,400 advisors and experts at more than 450 service locations^[44]. Federal funding covers half the cost; the rest comes from state and local governments, the private sector and client fees^[44].
• An AS9100 assistance example: In a case highlighted by NIST, Indiana's MEP Center used grant funding to support AS9100D internal auditor training and CNC skills training, and the company earned AS9100D in August 2023, meeting its customer's deadline^[45].
• A state example (Kansas): Kansas offers aviation tax credits: up to $5,000 a year for qualified new hires, and for employers, 10% of the compensation paid to newly hired qualified employees (up to $15,000 per employee per year for the first five years) and up to 50% of employee tuition reimbursement^[46]. A bill extending them through the end of 2036 passed in the 2026 legislative session^[47].

State programs differ in name and terms from state to state, and application windows change every year. Check with your state economic development office or local MEP Center before applying.

Order of steps to entry (guideline)

1. Write down your strengths that matter in aerospace: Difficult-to-cut materials (titanium, Inconel), thin-wall and large monolithic parts, 5-axis, hole position accuracy, high-mix low-volume work, recordkeeping, and so on.
2. Gather information from MEP Centers and state offices: Talk with your local MEP Center about state support and which tiers are looking for what^[44].
3. ISO 9001 → AS9100D: Get quotes from certification bodies, and run the system for about six months before the audit^[24].
4. Prototypes and FAI: Undergo the customer's audit and submit prototypes and AS9102 records. Decide your special-process subcontractors and how you will handle export control at this stage.
5. Production and growth: Build a delivery and quality track record; then Nadcap if you bring special processes in-house, supplying PMA holders for replacement parts, or ITAR registration for defense.

The real hurdles and how to deal with them

Companies that fit, and those that should think twice

FAQ

Can I do aerospace work without AS9100?

It's not required by law, but because production approval holders are responsible for controlling their suppliers^[12], many customers require AS9100D. When they require it varies by customer, so check before you start selling. Nadcap also requires AS9100 or an AC7004 audit^[35].

Do I need FAA approval?

Not if you machine parts as a subcontractor. The FAA does not approve suppliers; responsibility rests with the production approval holder. However, the FAA may come to monitor a supplier's facility^[13]. If you want to sell replacement parts under your own name, you need a PMA^[10][9].

Does a machining-only shop need Nadcap?

Ordinary machining is not automatically covered. Drilling, turning, milling, grinding and similar operations that a customer designates as special processes are audited under “Conventional Machining as a Special Process” (AC7126)^[34]. In most cases, the question you will face first is whether you send heat treatment and surface treatment to accredited subcontractors.

How much does certification cost?

Certification body audit fees depend on the number of audit days, and there's no official benchmark. The published fixed costs are the OASIS certificate fee ($700 per initial or recertification certificate) and the $250 digital fee per audit^[22][23]. For training, you can consult your local MEP Center^[44].

Can I go after military aircraft parts at the same time?

The quality system is the same, but manufacturing defense articles requires ITAR registration ($3,000 a year for new registrants) even if you don't export^[37][38], and DoD contracts add CMMC^[42] and specialty metals restrictions^[43]. It's more realistic to build a track record in commercial aviation first.

For cutting conditions for difficult-to-cut materials, see the Materials database; for tool wear, the tool life article; and for 5-axis, the 5-axis machining page, hole and fit data: Fits and Tolerances, and dimensional change from surface treatment: How to tell black oxide from plating, and how dimensions change.