Propeller deicing fluid

This regulation addresses the use of combustible (flammable) fluids for deicing propellers on aircraft operated under Part 121 (scheduled air carriers). If an airline uses such fluids, it must follow the requirements in § 121.255, which covers the handling and storage of flammable materials.

In practice, this means airlines using combustible propeller deicing fluids must establish procedures for their safe handling, ensure proper storage away from ignition sources, and train personnel accordingly. The cross-reference to § 121.255 brings in broader safety requirements for any flammable fluid used in aircraft operations.

This matters because propeller deicing fluids like isopropyl alcohol are often flammable, creating fire hazards during ground operations. The regulation ensures airlines don't overlook these risks simply because the fluid serves a deicing purpose rather than being fuel or another obvious flammable material. Airlines may alternatively choose non-combustible deicing fluids to avoid these additional compliance requirements.

*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.*