What is the primary function of the transponder in IFR operations?

The primary function of the transponder in IFR operations is to provide location information to air traffic control for situational awareness. This device emits a signal that includes the aircraft's identification, altitude, and other information, allowing air traffic controllers to effectively track the aircraft's position in real-time. This capability is essential for ensuring safe separation between aircraft, especially in busy airspace, and aids in the overall management of air traffic.

While communication with ground control is important for IFR operations, it is not the core function of the transponder. Weather detection and fuel efficiency are also not the functions of a transponder, as it does not provide meteorological data or influence fuel consumption. Therefore, it is clear that the transponder's main role centers on enhancing safety and awareness through accurate position reporting.