Protection of other airplane components against fire

This regulation requires fire-resistant materials on airplane surfaces near the engines to prevent fire from spreading. Specifically, any surface behind the engine nacelles (the housings around the engines) must be fire-resistant if it falls within one nacelle diameter on either side of the nacelle's centerline.

However, there's an important exception: tail surfaces behind the nacelles don't need this fire-resistant treatment unless the airplane's design puts them close enough that heat, flames, or sparks from an engine fire zone could readily reach them.

This matters because engine compartments are designated fire zones where fires are most likely to occur. By requiring fire-resistant materials in nearby areas, the regulation helps contain potential engine fires and prevents them from spreading to other parts of the aircraft structure. The exception for distant tail surfaces recognizes that some aircraft designs position the tail far enough away that fire spread isn't a realistic concern.

*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.*