Which term describes ensuring separation by visual observation before and after visual separation is applied?

The term that describes ensuring separation by visual observation before and after visual separation is applied is visual separation. This concept is integral in air traffic control, where controllers ensure that aircraft maintain safe distances from one another through visual cues.

Visual separation allows pilots and controllers to maintain awareness of nearby aircraft, utilizing their visual capacity to assess distances and positions. This method often complements procedural controls when weather conditions permit, allowing for more flexible traffic management and reduced delays.

While other terms like flight monitoring and altitude separation focus on different aspects of air traffic management—like tracking aircraft as they behave in the airspace or ensuring vertical separation, respectively—they do not specifically entail visual observation of nearby aircraft. Crossing separation also refers to the management of aircraft that are on intersecting paths but does not emphasize visual monitoring. Hence, visual separation is the most accurate term for the described process.