What is the function of UNICOM in aviation communication?

UNICOM serves a vital role in aviation communication, particularly at airports that do not have an air traffic control (ATC) tower. It facilitates communication between pilots and other personnel on the ground, allowing them to share important information about flight operations, such as taxiing, takeoff, landing intentions, and local traffic advisories. This communication is essential to ensure safety and coordination when ATC is not available.

In the context of non-towered airports, UNICOM provides a means for pilots to announce their positions and intentions while flying in the vicinity, thus enhancing situational awareness among all operators in the area. This helps to avoid misunderstandings and potential collisions, contributing to overall safety.

The other options (air traffic control, broadcasting weather information, and relaying signals from ground forces) do not accurately reflect the primary function of UNICOM, which is specifically focused on facilitating communication between pilots and ground personnel rather than managing air traffic or performing roles related to weather or military operations.