---
kind: "section"
citation: "14 C.F.R. § 25.991"
title: "14"
number: "25.991"
heading: "Fuel pumps."
url: "https://uscodex.org/cfr/14/25.991"
---

# §25.991. Fuel pumps.

- (a) **Main pumps.** Each fuel pump required for proper engine operation, or required to meet the fuel system requirements of this subpart (other than those in [paragraph (b)](#b) of this section, is a main pump. For each main pump, provision must be made to allow the bypass of each positive displacement fuel pump other than a fuel injection pump (a pump that supplies the proper flow and pressure for fuel injection when the injection is not accomplished in a carburetor) approved as part of the engine.
- (b) **Emergency pumps.** There must be emergency pumps or another main pump to feed each engine immediately after failure of any main pump (other than a fuel injection pump approved as part of the engine).

## Notes

### Authority

Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702 and 44704; Pub. L. 115-254, 132 Stat 3281 (49 U.S.C. 44903 note).

### Source

Source: Docket No. 5066, 29 FR 18291, Dec. 24, 1964, unless otherwise noted.