How are frequencies and channels on the STBY side of the CNC activated?

The activation of frequencies and channels on the STBY side of the CNC is accomplished through the use of the XFER button. This button is designed to transfer the selected frequency or channel from the standby position to the active position. When the XFER button is pressed, the frequency or channel that is currently in standby becomes the one that is used for communication, allowing the pilot to manage radio communications effectively.

The functionality of the XFER button is crucial during operations where quick changes to radio settings are necessary. It allows pilots to prepare secondary frequencies without interrupting current communications, enhancing operational efficiency and safety.

In contrast, the other buttons—COMM, IDENT, and MODE—serve different purposes. The COMM button is typically used for general radio communication settings, while the IDENT button is associated with the transponder functions, and the MODE button is related to selecting operational modes for various systems. Each of these buttons plays a specific role within the cockpit interface, but they do not activate standby frequencies directly.