---
kind: "range"
citation: "14 C.F.R. §§ 25.1549–25.1553"
title: "14"
from: "25.1549"
to: "25.1553"
count: 3
url: "https://uscodex.org/cfr/14/25.1549..25.1553"
---

# §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.

# §25.1551. Oil quantity indication.


Each oil quantity indicating means must be marked to indicate the quantity of oil readily and accurately.


# §25.1553. Fuel quantity indicator.


If the unusable fuel supply for any tank exceeds one gallon, or five percent of the tank capacity, whichever is greater, a red arc must be marked on its indicator extending from the calibrated zero reading to the lowest reading obtainable in level flight.