When is a gun-target line considered hot?

A gun-target line is considered hot when the firing unit is actively firing. This means that the weapon system is in the process of launching projectiles toward the designated target, indicating that the engagement has entered an action phase. It denotes a critical moment where safety and operational measures are essential due to the release of ordnance.

When a firing unit is actively engaged in firing, it can also affect the overall situation around it, necessitating the management of nearby airspace and ground activity to ensure safety and effectiveness. This concept is vital for coordination among units and for maintaining situational awareness on the battlefield.

Other options revolve around preliminary actions that do not constitute a hot gun-target line. For example, while the gun needs to be laid correctly, and the Fire Direction Center (FDC) must receive the Call For Fire (CFF) for the engagement to begin, these actions alone do not result in a hot status. Similarly, establishing communications is a preparatory step, but the gun-target line only becomes hot when the actual firing is underway.