What is the primary function of a navigation radio in aircraft?

The primary function of a navigation radio in aircraft is to assist in navigation and determine position. Navigation radios receive signals from various ground-based or satellite systems, which helps pilots ascertain their aircraft's location in relation to airway routes, navigational aids, and specific waypoints. This capability is essential for safe and efficient routing during flights, ensuring that pilots can follow designated flight paths and make necessary adjustments based on their current position.

Other options may relate to important aspects of flying, such as communication or gathering flight information, but they do not accurately capture the primary purpose of a navigation radio, which is focused specifically on navigation. For instance, while communication with air traffic control is vital for maintaining safe distances and receiving instructions, it is not the main function of a navigation radio. Similarly, gathering and displaying flight information pertain more to flight instruments like the attitude indicator or altimeter, rather than the specific role of aiding a pilot's navigation.