Cabin interiors

This regulation sets fire safety standards for aircraft cabin interiors operated under Part 121 (commercial airlines). All crew and passenger compartments must use materials that resist fire to varying degrees:

• Basic materials must be at least "flash resistant" (won't ignite instantly from brief flame contact)
• Wall/ceiling linings, upholstery, floors, and furnishings must be "flame resistant" (won't support continued burning)

If smoking is permitted in a compartment, it must have completely removable self-contained ashtrays. Non-smoking areas must display no-smoking placards.

Waste receptacles for towels, papers, and trash must be made of fire-resistant material and include covers or other containment features to prevent fires from spreading if contents ignite.

These requirements matter because cabin fires can spread rapidly in enclosed aircraft spaces, threatening passenger safety and aircraft control. The layered approach—from flash-resistant base materials to flame-resistant finishes—provides critical time for crew response and passenger evacuation in fire emergencies.

*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.*