MINATION AND PREDICTION

A process is provided for establishing when selected pairs of airborne aircraft are in en route conflict or are in potential en route conflict. The process includes a number of "filtering" steps arranged in three branches. At each step, different conditions, such as height separation, lateral separation, height convergence, lateral convergence and "look-ahead" projections are examined for each aircraft pair. Criteria are established for each "filtering" step such that aircraft pairs not passing the filter to the next step are exited as either "no conflict", "current conflict" as "potential conflict". Sixteen such filtering steps are provided, one of which establishes a "current conflict" status and four of which establish a "potential conflict" status.