---
kind: "section"
citation: "14 C.F.R. § 21.9"
title: "14"
number: "21.9"
heading: "Replacement and modification articles."
url: "https://uscodex.org/cfr/14/21.9"
---

# §21.9. Replacement and modification articles.

- (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be installed on a type-certificated product, the person may not produce that article unless it is—
  - (1) Produced under a type certificate;
  - (2) Produced under an FAA production approval;
  - (3) A standard part (such as a nut or bolt) manufactured in compliance with a government or established industry specification;
  - (4) A commercial part as defined in [§ 21.1](/cfr/14/21.1.md) of this part;
  - (5) Produced by an owner or operator for maintaining or altering that owner or operator's product;
  - (6) Fabricated by an appropriately rated certificate holder with a quality system, and consumed in the repair or alteration of a product or article in accordance with [part 43](/cfr/14/part43.md) of this chapter; or
  - (7) **Produced in any other manner approved by the FAA.**
- (b) Except as provided in [paragraphs (a)(1) through (a)(2)](#a-1..a-2) of this section, a person who produces a replacement or modification article for sale may not represent that part as suitable for installation on a type-certificated product.
- (c) Except as provided in [paragraphs (a)(1) through (a)(2)](#a-1..a-2) of this section, a person may not sell or represent an article as suitable for installation on an aircraft type-certificated under §§ [21.25(a)(2)](/cfr/14/21.25.md?p=a-2) or [21.27](/cfr/14/21.27.md) unless that article—
  - (1) Was declared surplus by the U.S. Armed Forces, and
  - (2) Was intended for use on that aircraft model by the U.S. Armed Forces.

## Notes

### Amendments

[Doc. No. FAA-2006-25877, Amdt. 21-92, 74 FR 53385, Oct. 16, 2009; Amdt. 21-92A, 75 FR 9095, Mar. 1, 2010; Doc. No. FAA-2015-1621, Amdt. 21-100, 81 FR 96688, Dec. 30, 2016]

### Authority

Authority: 42 U.S.C. 7572; 49 U.S.C. 106(f), 40105, 40113, 44701-44702, 44704, 44707, 44709, 44711, 44713, 44715, 45303.

### Amendments

[Doc. No. FAA-2006-25877, Amdt. 21-92, 74 FR 53385, Oct. 16, 2009; Amdt. 21-92A, 75 FR 9095, Mar. 1, 2010; Doc. No. FAA-2015-1621, Amdt. 21-100, 81 FR 96688, Dec. 30, 2016]