If "danger close" is announced, what additional information must be passed to attacking aircraft?

When "danger close" is announced, it indicates that friendly forces are operating within a certain proximity of the target where the risk of collateral damage or friendly fire is significantly heightened. In this context, it is critical for attacking aircraft to receive the Ground Commander's initials as this signifies the approval and authority from the commander on the ground to proceed with engaging the target despite the risks involved.

This information ensures that the attacking aircraft are acting under proper command authorization, emphasizing the seriousness of deploying firepower in close proximity to friendlies. The Ground Commander’s initials are crucial because they validate that the decision to engage has been made with full awareness of the potential risks and consequences.

While the other options, such as the grid to the nearest friendlies, time to engage, and type of weapon being used are vital pieces of information, they do not carry the same level of command authority and situational awareness that the Ground Commander's initials provide. Thus, the initials serve as a key indicator of both risk management and tactical decision-making in a dangerous and fluid combat scenario.