Public address and crewmember interphone systems

This regulation requires aircraft with more than 19 passenger seats to have both a public address (PA) system and a crewmember interphone system.

The PA system must work independently from the interphone, be accessible from both pilot seats, and allow flight attendants to make announcements within 10 seconds from their stations. It must be audible throughout the cabin, including lavatories. Flight attendants seated near floor-level emergency exits need readily accessible microphones.

The interphone system enables two-way communication between the cockpit and passenger compartments, galleys on other deck levels, and flight attendant stations. Large turbojets need additional features: interphone access at stations where all floor-level exits are visible, an alerting system that distinguishes normal from emergency calls, and ground-to-cockpit communication capability when parked (with the ground station positioned to avoid detection from inside).

Both systems ensure pilots and flight attendants can communicate effectively 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.*