---
kind: "section"
citation: "14 C.F.R. § 25.1731"
title: "14"
number: "25.1731"
heading: "Powerplant and APU fire detector system: EWIS."
url: "https://uscodex.org/cfr/14/25.1731"
---

# §25.1731. Powerplant and APU fire detector system: EWIS.

- (a) EWIS that are part of each fire or overheat detector system in a fire zone must be fire-resistant.
- (b) No EWIS component of any fire or overheat detector system for any fire zone may pass through another fire zone, unless:
  - (1) It is protected against the possibility of false warnings resulting from fires in zones through which it passes; or
  - (2) **Each zone involved is simultaneously protected by the same detector and extinguishing system.**
- (c) EWIS that are part of each fire or overheat detector system in a fire zone must meet the requirements of [§ 25.1203](/cfr/14/25.1203.md).

## Notes

### Source

Source: Docket No. FAA-2004-18379, 72 FR 63406, Nov. 8, 2007, unless otherwise noted.

### 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.