Public address system

This regulation requires Part 121 air carriers operating airplanes with more than 19 passenger seats to install a public address (PA) system. The PA system must work independently from the crew interphone system (though they can share certain components like handsets and microphones), and it must be FAA-approved.

The system must be immediately accessible from both pilot seats in the cockpit. Flight attendants must be able to activate it within 10 seconds from their stations, and there must be microphones near floor-level emergency exits with adjacent flight attendant seats (one microphone can serve multiple nearby exits if attendants can talk to each other). The PA must be audible throughout the cabin—at every passenger seat, lavatory, and flight attendant station.

For transport category airplanes built after November 27, 1990, additional technical standards apply. This ensures pilots and flight attendants can quickly communicate safety information to all passengers during normal operations and 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.*