What FAA PMA is, and what it is not
If you work in aerospace sustainment, you have seen PMA referenced in RFQs, supplier qualification checklists, and approvals packages.
The FAA defines Parts Manufacturer Approval (PMA) as a combined design and production approval for modification and replacement articles, allowing a manufacturer to produce and sell those articles for installation on type-certificated products.
PMA is not a marketing label. It is an approval framework that ties together:
- Design data and compliance basis
- Production controls and quality system expectations
- Ongoing conformity and safety for installation
The FAA’s PMA regulations and policy references point to 14 CFR Part 21 Subpart K and related guidance.
Two common paths in PMA design approval: identicality vs test and computation
In the FAA’s PMA design approval overview, the agency notes that compliance can be shown through tests and computations unless the article is identical to the article design on a type-certificated product.
This distinction matters because it changes what “support” looks like from a manufacturer.
If you are a PMA holder or working with one, your build partner needs to be able to:
- Hold tight control on critical characteristics
- Maintain repeatable processes
- Provide documentation that supports the compliance basis
- Communicate clearly when a change requires engineering review
Where suppliers often create risk in PMA-driven work
Most PMA-driven issues show up in the gap between design intent and production reality:
- Material substitutions that are not documented
- Coatings or outside processing that drift from requirements
- Inspection plans that do not protect the functional characteristics
- Changes to tooling, methods, or subcontractors without visibility
- Confusing language around what is “approved” vs “conforms”
Radial’s own aerospace catalog includes an important example of why wording matters: some bearings may conform to materials, dimensions, and configurations of Mil-B-81935, however Radial is not approved for procurement under that specification, and the catalog instructs customers to consult the factory for additional information.
That is the right kind of clarity. It separates technical conformity from procurement eligibility.
What “build to PMA specifications” should mean in practice
If a buyer asks you to build to PMA specifications, the practical need is usually:
- Build to print with tight control of critical characteristics
- Traceable materials and controlled special processes
- Inspection records that match the documentation plan
- Repeatability across lots, not just a successful first run
This is where engineering partnership and quality systems matter. Radial’s differentiators page frames certified reliability as a core strength, supported by AS9100 and ISO certifications, and emphasizes U.S.-based manufacturing for responsiveness and supply chain stability.
Radial’s Custom Capabilities page also emphasizes collaborative engineering, metals and coatings expertise, rapid response, precision manufacturing, and assembly support.
The documentation package: what to ask for
To keep PMA-driven work clean, ask your supplier how they handle:
- Material certifications and traceability
- Outside processing control and verification
- Inspection planning tied to critical characteristics
- Nonconformance handling and corrective action loop
- Change control, including process and supplier changes
If you are not sure what to request, start with the part’s functional risk:
- Is it flight-critical or safety-critical?
- Does it sit in a harsh environment (heat, vibration, corrosion)?
- Is it high-cycle?
- Is it installed in a constrained geometry where misalignment is a factor?
Radial’s “Who We Serve” positioning reinforces the reality of these environments and calls out extreme loads, vibration, and environmental conditions.
How reverse engineering fits into PMA-related programs
Reverse engineering shows up in PMA-related work when the installed base is old, documentation is incomplete, or the incumbent supply is constrained. The right approach is still controlled:
- Work from the best available input: drawing, sample, legacy data
- Confirm the compliance basis and what can be changed
- Translate requirements into inspection characteristics
- Avoid “close enough” substitutions
Radial’s catalog supports special design requirements when standard products do not meet customer needs, including designing and manufacturing completed assemblies in many cases.
That is the capability foundation that makes disciplined replacement work possible.
A practical next step
If you have a PMA-driven replacement or modification program and need a manufacturing partner that can support engineering review, documentation discipline, and controlled production, start with an engineering conversation.
- Custom capabilities: https://radialbearing.com/custom-capabilities/
- Contact: https://radialbearing.com/contact-us/