What is the audible cabin indicator when the lavatory smoke detector is activated?

• A. Cabin chime over PA system sounds
• B. Alarm bell in cockpit sounds
• C. Cabin lights flash
• D. Air horn sounds

Answer: (A)

When the lavatory smoke detector activates, the system is designed to alert the cabin crew through a distinct chime delivered over the cabin PA system. This audible cue is meant to quickly grab flight attendants' attention in the cabin so they can respond, inspect the lavatory, and coordinate the appropriate procedures. It’s a cabin-focused alert, aimed at crew in service areas, rather than a cockpit-wide alarm. Other options—like an alarm in the cockpit, lights flashing, or an air horn—would either be too disruptive or reserved for different types of warnings, so the cabin chime over the PA is the standard indication for this situation.