---
kind: "section"
citation: "14 C.F.R. § 121.335"
title: "14"
number: "121.335"
heading: "Equipment standards."
url: "https://uscodex.org/cfr/14/121.335"
---

# §121.335. Equipment standards.

- (a) **Reciprocating engine powered airplanes.** The oxygen apparatus, the minimum rates of oxygen flow, and the supply of oxygen necessary to comply with [§ 121.327](/cfr/14/121.327.md) must meet the standards established in [section 4b.651](/cfr/14/4b.651.md) of the Civil Air Regulations as in effect on July 20, 1950, except that if the certificate holder shows full compliance with those standards to be impracticable, the Administrator may authorize any change in those standards that he finds will provide an equivalent level of safety.
- (b) **Turbine engine powered airplanes.** The oxygen apparatus, the minimum rate of oxygen flow, and the supply of oxygen necessary to comply with §§ [121.329](/cfr/14/121.329.md) and [121.333](/cfr/14/121.333.md) must meet the standards established in [section 4b.651](/cfr/14/4b.651.md) of the Civil Air Regulations as in effect on September 1, 1958, except that if the certificate holder shows full compliance with those standards to be impracticable, the Administrator may authorize any changes in those standards that he finds will provide an equivalent level of safety.

## Notes

### Source

Source: Docket 6258, 29 FR 19205, Dec. 31, 1964, unless otherwise noted.

### Authority

Authority: 49 U.S.C. 106(f), 40103, 40113, 40119, 41706, 42301 preceding note added by Pub. L. 112-95, sec. 412, 126 Stat. 89, 44101, 44701-44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 44729, 44732; 46105; Pub. L. 111-216, 124 Stat. 2348 (49 U.S.C. 44701 note); Pub. L. 112-95, 126 Stat. 62 (49 U.S.C. 44732 note); Pub. L. 115-254, 132 Stat. 3186 (49 U.S.C. 44701 note).