What distance must be maintained when using suitable landmarks for same runway separation?

In air traffic control, maintaining safe separation between aircraft is a critical aspect of ensuring safety in flight operations. When using suitable landmarks for same runway separation, the correct distance that must be maintained is based on the length of the runway. This requires that aircraft be separated by a distance equivalent to the length of the runway to ensure that one aircraft is completely clear of the runway before another begins its takeoff or landing maneuver.

Utilizing the length of the runway as a standard for separation provides a clear and measurable guideline that enhances safety by accounting for the performance characteristics of different aircraft. It helps in avoiding potential collisions or conflicts, particularly during high-density traffic situations. The use of visual landmarks alone or considering only time or aircraft size for separation does not provide the same level of assurance and clarity that the length of the runway does, as these factors can be more subjective and less precise.