In what circumstance should nonradar separation be used over radar separation?

Nonradar separation should be used over radar separation when an operational advantage is realized. This situation can occur when the use of nonradar separation can enhance the efficiency of air traffic flow, reduce workload, or provide better adherence to air traffic management procedures. For instance, in certain airspace configurations or during specific traffic scenarios, employing nonradar techniques might streamline coordination among aircraft, lead to more efficient routings, or optimize available resources.

Utilizing nonradar separation in these cases can also cater to specific procedural requirements or align with established air traffic control protocols, ultimately contributing to improved safety and operational efficiency. Thus, recognizing and capitalizing on situations where nonradar separation provides a tangible benefit is key to effective air traffic management.