What is used as a means of station identification?

• A. Call sign
• B. Call letters
• C. Identifier
• D. Station name

Answer: (A)

In radiotelephony, the way a station proves who it is is by sending its call sign—the unique designator assigned to that station by the aviation authority. This call sign serves as the official identifier you use to address and recognize the transmitting party, and it must be spoken at the start of a transmission and at designated intervals. For an aircraft, the call sign often reflects the aircraft’s registration (for example, N12345) or, for airline operations, the flight number with the carrier’s designator. Terms like call letters, identifier, or station name aren’t the standardized means of identification in aviation radio communications, so the correct choice is the call sign.