In COLD mode, when are the interphone microphones active?

In COLD mode, the interphone microphones are designed to function only when specific switches are activated. This means that they are off by default to avoid any accidental transmission or noise, which is essential during certain operations, especially on the ground or during preparations.

The interphone system requires either the ICS KEY switch or the KEY/MUTE switch to be in the activated position to allow the microphones to be active. This ensures that communications are controlled and that the potential for unintended transmissions is minimized. By requiring the activation of these switches, the system provides a level of control and safety, allowing crew members to communicate only when necessary.

This design plays an important role in managing cockpit and cabin communications, particularly in a training environment or in situations where maintaining silence can be crucial for the operation and safety of the aircraft.