The term used to describe the code transmitted by the transponder to identify the aircraft to ATC is known as what?

• A. Squawk value
• B. Transponder code
• C. Beacon number
• D. Callsign signal

Answer: (B)

In radar identification, ATC recognizes an individual aircraft by the four-digit code that the transponder transmits in response to radar interrogations. This code is entered into the transponder by the pilot and stays with the aircraft as its published identity on radar. The formal term for that code is the transponder code. It’s the same concept pilots often call a squawk code, since it’s the code used during squawk interrogations. For context, standard values like 1200 are used for routine VFR in many airspaces, while special codes such as 7500, 7600, and 7700 indicate hijack, radio failure, and emergency, respectively. A beacon number isn’t a term used for ATC identification, and the callsign signal refers to the radio voice identifier, not the transponder’s automatic code.