How often must an ATC transponder system be certified?

The certification of an ATC transponder system must occur every 24 calendar months. This requirement is established by FAA regulations to ensure that transponder systems, which are essential for air traffic control and safety, are functioning correctly and transmitting accurate information.

The 24-month period allows enough time for proper maintenance and verification of the system's operational integrity while balancing the need for safety. This regular certification helps to maintain high standards in aviation operations and minimizes the likelihood of malfunction, contributing to overall air traffic safety.

While there are other time frames mentioned in the choices, they do not align with the established requirements for transponder certification as stipulated by regulations. The importance of maintaining this schedule emphasizes the role of transponders in collision avoidance and efficient air traffic management in controlled airspace.