On Interphone Code 26, what does a steady yellow call light indicator (one high chime) indicate?

• A. Flight deck emergency
• B. Guest Seat Call
• C. Lavatory assistance request
• D. Smoke detector fault

Answer: (C)

Interphone signaling uses color and tone to quickly convey where a request is coming from and how urgent it is. A steady yellow call light with a single high-pitched chime is the lavatory assist signal. It tells the crew that someone in the lavatory needs help or attention, not an emergency requiring flight deck action. This pattern is distinct from other calls—for example, an emergency from the flight deck would use a more urgent indication, a guest seat call comes from a passenger seat and uses a different color/pattern, and a smoke detector fault would be directed to maintenance. When this signal appears, respond by going to the lavatory to assist as needed, such as confirming occupancy, opening the door if requested, or providing the requested help.