JO 7110.65 1-2-2

The following definitions must be used in the application of the separation criteria in this order.

NOTE-

The term “protected airspace,” as used in this paragraph, is the airspace equal to one half the required applicable lateral separation on either side of an aircraft along its projected flight path. If the protected airspace of two aircraft does not overlap, applicable lateral separation is ensured.

SAME COURSES are courses whose protected airspaces are coincident, overlap, or intersect and whose angular difference is less than 45 degrees. (See FIG 1-2-1.)

CROSSING COURSES are intersecting courses whose angular difference is 45 through 135 degrees inclusive. (See FIG 1-2-1.)

OPPOSITE/RECIPROCAL COURSES are courses whose protected airspaces are coincident, overlap, or intersect and whose angular difference is greater than 135 degrees through 180 degrees inclusive. (See FIG 1-2-1.)