In visual separation approvals, which aircraft needs to be visually observed?

In visual separation approvals, it is crucial that at least one of the aircraft involved is visually observed by the controller to ensure safe separation and prevent potential conflicts. This requirement allows the controller to maintain situational awareness of the positions and intentions of the aircraft while they operate in proximity to one another. By visually observing at least one aircraft, the controller can ensure that separation is maintained and confirm that the aircraft are on the correct flight paths and executing their maneuvers safely.

While observing both aircraft can enhance safety and situational awareness, the key requirement for visual separation is that at least one aircraft must be visually tracked to establish the necessary separation. This approach allows for effective oversight and management of the air traffic involved.