What are the transmit and receive frequencies of an aircraft's mode C transponder?

The mode C transponder used in aircraft operates with specific frequency allocations for transmitting and receiving signals. The correct frequencies are significant for air traffic control and the proper functioning of secondary surveillance radar systems.

In this case, the mode C transponder transmits at 1090 MHz. This frequency serves as the standard for the transponder's replies to interrogation signals. For receiving signals, the mode C transponder operates at 1030 MHz. This frequency is used by air traffic control radar systems to send interrogation signals to the transponder, prompting it to reply with the aircraft's information.

This configuration allows for effective communication and identification of aircraft within controlled airspace, allowing air traffic controllers to manage and monitor air traffic efficiently. The choice of 1090 MHz for transmission and 1030 MHz for reception is standardized for all aircraft using mode C transponders, ensuring consistency and reliability across the aviation industry.