On Interphone Code 26, what does a flashing red call light indicator with three high-low chimes indicate?

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

Answer: (C)

Interphone codes use both light signals and chime patterns to convey urgency and origin. A flashing red call light paired with three high-low chimes is the emergency alert pattern associated with calling the flight deck under Code 26. That combination is designed to grab attention immediately and indicate a flight deck emergency requires prompt action from crew. The other options—guest seat call, lavatory assistance, or a smoke detector fault—use different light and chime patterns and would not show the flashing red light with the three high-low chimes, so they don’t fit this code.