Extinguishing agent container compartment temperature

This regulation requires that fire extinguishing agent containers on Part 121 aircraft be installed in locations where temperatures stay within a reasonable range. The concern is that extreme temperatures—whether too hot or too cold—can affect how well fire extinguishing agents work when needed.

If containers are exposed to excessive heat, the agents inside may degrade, lose pressure, or become less effective. Conversely, extreme cold can also impair the chemical properties or discharge characteristics of extinguishing agents. By requiring installation in temperature-controlled or moderate-temperature areas, this rule ensures the fire suppression system will function properly during an emergency.

This is a design and installation requirement that aircraft manufacturers and maintenance personnel must consider when locating extinguisher bottles in cargo compartments, engine nacelles, or other areas equipped with fire suppression systems. The goal is reliable fire protection when seconds matter.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*