What role does a transponder primarily play in air traffic control?

A transponder plays a critical role in air traffic control by sending altitude and location data to ground radar systems. Specifically, when an aircraft is equipped with a transponder, it responds to interrogations from radar systems by transmitting information about its current position and altitude. This data is crucial for air traffic controllers, as it helps them identify and track aircraft on their radar displays, ensuring safe separation and efficient management of air traffic.

This information allows air traffic control to monitor not just where an aircraft is flying, but also its vertical position, which aids in maintaining safe altitudes between different aircraft. The transponder's ability to broadcast this data enhances situational awareness for both controllers and pilots, reducing the likelihood of collisions and improving overall airspace safety.

While communication of pilot intentions and activation of navigation systems are important functions in aviation, they are not the primary roles of a transponder. Similarly, recording flight data for analysis is typically done by other devices onboard the aircraft rather than the transponder itself.