The code on the interphone to call the flight deck normally is ______.

• A. 12
• B. 21
• C. 9
• D. 19

Answer: (B)

Interphone systems use predefined two‑digit codes to route calls to different locations on the aircraft. The code that connects you to the flight deck is the standard flight deck call code. It’s chosen to be quick and unique so flight crew can be summoned reliably when needed, while other two‑digit codes are reserved for other areas or functions. Using the correct flight deck code ensures the pilots receive the alert directly and promptly, whereas the other codes would route to different stations and not reach the cockpit.