FAR 21.319 — PMA Design Changes
FAR 21.319 explains how minor and major design changes to Parts Manufacturer Approval (PMA) articles are classified and approved by the FAA.
In Plain English
FAR 21.319 governs how design changes are handled for articles produced under a Parts Manufacturer Approval (PMA). The rule splits changes into two categories based on impact to the approval basis:
- Minor change: A design change that has no appreciable effect on the approval basis of the article.
- Major change: Any change that is not minor — in other words, anything that could meaningfully affect the original approval.
The approval path depends on which category the change falls into:
- Minor changes may be approved using a method acceptable to the FAA (typically documented in the PMA holder's procedures).
- Major changes require FAA approval before the PMA holder may incorporate them into the design of a produced article.
Why it matters: PMA parts are installed on certificated aircraft, so uncontrolled design drift could compromise airworthiness. This rule ensures the FAA stays in the loop on anything that could affect how a part performs or fits its approval basis.
Regulation Text
14 CFR § 21.319§ 21.319 Design changes.
(a)(1) A “minor change” to the design of an article produced under a PMA is one that has no appreciable effect on the approval basis.
(2) A “major change” to the design of an article produced under a PMA is any change that is not minor.
(b)(1) Minor changes to the basic design of a PMA may be approved using a method acceptable to the FAA.
(2) The PMA holder must obtain FAA approval of any major change before including it in the design of an article produced under a PMA.
Oral Exam Questions a DPE Might Ask
Q1What's the difference between a minor and a major design change to a PMA article?
Per FAR 21.319, a minor change has no appreciable effect on the approval basis, while a major change is any change that isn't minor.
Q2Can a PMA holder incorporate a major design change before getting FAA approval?
No. FAR 21.319(b)(2) requires the PMA holder to obtain FAA approval of any major change before including it in the design of an article produced under the PMA.
Q3How are minor changes to a PMA design approved?
Under FAR 21.319(b)(1), minor changes may be approved using a method acceptable to the FAA, rather than requiring direct FAA sign-off on each change.
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Related Sections in Part 21