Description

Composite separation is a combination of vertical separation and one of the other forms of horizontal separation (lateral or longitudinal). It allows using minima for each which may be lower than, but not less than half of, those used for each of the combined elements when applied individually. Composite separation is applied on the basis of regional air navigation agreements. It should be noted that composite separation is not meant to be used in surveillance environment, i.e. the combination of 500 ft vertical and 2.5 NM horizontal separation is out of scope.

Composite separation is a means of improving airspace utilization and safety in route systems where conventional lateral separation is 90 NM or greater, due to the dispersion of some flights to other routes and altitudes.

Composite separation may be considered where navigation is dependent on long-distance station-referenced aids and/or on self-contained systems and the frequency of flights crossing the axis of the track system is not significant.