What is one of the main user interfaces of an Aircraft Earth Station (AES)?

The primary user interface of an Aircraft Earth Station (AES) is the telephone system. This interface enables pilots and crew to communicate with ground stations, air traffic control, and other necessary parties during flight. The telephone functionality is essential for operational communications and maintaining contact with various entities, which is critical for safety and coordination in aviation.

Unlike systems such as television, aircraft navigation systems, or flight data recorders, which serve different specific purposes, the telephone interface directly supports communication needs, making it a central feature of the AES. The ability to relay voice communications helps in adhering to regulations and facilitating efficient flight operations.