Lavatory fire protection

This regulation requires Part 121 air carriers operating passenger-carrying airplanes to equip each lavatory with two safety systems: a smoke detector and an automatic fire extinguisher in waste receptacles.

The smoke detector must alert either the cockpit (via warning light) or the cabin crew (via light or audio warning) so fires can be detected quickly. The built-in fire extinguisher must automatically discharge into towel and waste bins when fire occurs—these receptacles are common ignition points.

Smaller airplanes (30 seats or fewer) operated by certain certificate holders were temporarily exempt until December 1997. Additionally, non-transport category airplanes certificated after 1964 with 10-19 seats must have smoke detectors, but only need to alert the flight deck (not necessarily cabin crew).

These requirements address the serious risk of lavatory fires, which can spread rapidly in an enclosed space and threaten the aircraft if not detected and suppressed immediately.

*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.*