Under what circumstances should non-radar separation be preferred over radar separation?

Non-radar separation is preferred over radar separation when it is operationally advantageous due to specific circumstances that may dictate a need for its use. This could encompass various scenarios, such as ensuring that air traffic services maintain sufficient separation in areas where radar coverage is limited or when terrain or environmental factors impact radar effectiveness. In addition, non-radar separation can be more effective in managing aircraft in certain types of airspace, such as oceans or remote regions, where radar infrastructure is sparse.

Moreover, operational advantages could include situations where communication and procedural methods foster a higher level of safety or efficiency for the air traffic system. Non-radar methods may provide better coordination during high-traffic events or facilitate more efficient flight paths based on the aircraft's capabilities and the abstract navigation aids at hand, which can be particularly useful when dealing with VFR (Visual Flight Rules) or in adverse weather conditions where radar may not be as reliable.

While radar equipment failure indeed necessitates a switch to non-radar separation, relying solely on equipment status without considering operational context might not fully capture the best use of available resources. Likewise, ease of management, while important, does not inherently justify a preference unless it aligns with operational goals. Lastly, altitude alone does not determine the effectiveness or preference