What is the primary responsibility of the air traffic controller before authorizing a non-approach control tower to provide visual separation?

The primary responsibility of the air traffic controller before authorizing a non-approach control tower to provide visual separation is ensuring tower visibility on aircraft. This is crucial because visual separation relies on the ability of pilots to see each other and maintain safe distances between aircraft by visual means. If the tower cannot effectively see the aircraft or does not have the capability to visually monitor their positions, it compromises the safety and effectiveness of visual separation procedures.

In this context, visibility is fundamental not just for safety but also for the operational effectiveness of air traffic management. The controller must verify that the tower has a clear line of sight to the relevant traffic to ensure that the required separation can be maintained visually, thereby reducing the potential for any conflicts or collisions.

While confirming existing weather conditions is important for overall flight safety and can affect visibility, it is secondary to the immediate requirement of ensuring that the tower has adequate visual contact with the aircraft. Similarly, communicating with ground control and issuing a flight plan update are operational tasks that do not directly relate to the validation of visual separation capabilities in this specific circumstance.