---
kind: "section"
citation: "14 C.F.R. § 33.15"
title: "14"
number: "33.15"
heading: "Materials."
url: "https://uscodex.org/cfr/14/33.15"
---

# §33.15. Materials.


The suitability and durability of materials used in the engine must—

- (a) Be established on the basis of experience or tests; and
- (b) Conform to approved specifications (such as industry or military specifications) that ensure their having the strength and other properties assumed in the design data.

## Notes

### Amendments

[Amdt. 33-8, 42 FR 15047, Mar. 17, 1977, as amended by Amdt. 33-10, 49 FR 6850, Feb. 23, 1984]

### Authority

Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

### Source

Source: Docket No. 3025, 29 FR 7453, June 10, 1964, unless otherwise noted.

### Amendments

[Amdt. 33-8, 42 FR 15047, Mar. 17, 1977, as amended by Amdt. 33-10, 49 FR 6850, Feb. 23, 1984]