What does the term 'cooperative transponder' imply in SSR operation?

What does the term 'cooperative transponder' imply in SSR operation?

• A. The aircraft must carry and operate a functioning transponder that can respond to interrogations.
• B. The transponder is optional.
• C. The transponder only broadcasts weather.
• D. The transponder broadcasts only to ground units.

Answer: (A)

In SSR operation, data relies on the aircraft actively participating by responding to ground interrogations. A cooperative transponder is one that is turned on, functional, and able to reply to the ground radar’s interrogation with the aircraft’s identity (squawk) and, if equipped, altitude information (Mode C) or more advanced data (Mode S). This active cooperation lets the controller identify and track the aircraft precisely. If the transponder is unavailable or non-responsive, SSR cannot provide those data, and surveillance would depend only on primary radar returns or degrade accordingly. The other options aren’t correct because transponders are not optional in SSR, they don’t broadcast weather, and they don’t simply broadcast data to ground units without being interrogated.

In SSR operation, data relies on the aircraft actively participating by responding to ground interrogations. A cooperative transponder is one that is turned on, functional, and able to reply to the ground radar’s interrogation with the aircraft’s identity (squawk) and, if equipped, altitude information (Mode C) or more advanced data (Mode S). This active cooperation lets the controller identify and track the aircraft precisely. If the transponder is unavailable or non-responsive, SSR cannot provide those data, and surveillance would depend only on primary radar returns or degrade accordingly. The other options aren’t correct because transponders are not optional in SSR, they don’t broadcast weather, and they don’t simply broadcast data to ground units without being interrogated.