---
kind: "section"
citation: "14 C.F.R. § 25.1549"
title: "14"
number: "25.1549"
heading: "Powerplant and auxiliary power unit instruments."
url: "https://uscodex.org/cfr/14/25.1549"
---

# §25.1549. Powerplant and auxiliary power unit instruments.


For each required powerplant and auxiliary power unit instrument, as appropriate to the type of instrument—

- (a) Each maximum and, if applicable, minimum safe operating limit must be marked with a red radial or a red line;
- (b) Each normal operating range must be marked with a green arc or green line, not extending beyond the maximum and minimum safe limits;
- (c) Each takeoff and precautionary range must be marked with a yellow arc or a yellow line; and
- (d) Each engine, auxiliary power unit, or propeller speed range that is restricted because of excessive vibration stresses must be marked with red arcs or red lines.

## Notes

### Amendments

[Amdt. 25-40, 42 FR 15044, Mar. 17, 1977]

### 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.

### Amendments

[Amdt. 25-40, 42 FR 15044, Mar. 17, 1977]