What is the primary function of Mode A in transponder technology?

The primary function of Mode A in transponder technology is to provide identification for the aircraft. This mode transmits a basic four-digit squawk code that is assigned by air traffic control (ATC). This code allows ATC to identify the specific aircraft on their radar screens, facilitating effective communication and traffic management in controlled airspace.

Mode A does not provide altitude information, which is a function of Mode C. Unlike Modes C and S, which transmit additional data such as altitude and enhanced information, Mode A focuses solely on the aircraft’s identification. Understanding this fundamental aspect of transponder operations is crucial for pilots and air traffic controllers to ensure safety and efficiency in air traffic management.