i actually posted a suggestion for this a while back...
a DOT command like <.drone XXX> where XXX = the plane number.
possibly a <.dronepattern XXX> where XXX is the pattern they fly in.
pattern 1 is the normal counterclockwise circle
pattern 2 is a clockwise circle
pattern 3 is a straight line between the base you are at to the nearest other base, then poof and back to the start.
pattern 4 is a normal circle, but with the drones climbing, and diving either in a set pace, or random occurences. set the climb to 2K above the normal alt, and the dive to 1k below the normal alt.
probably a pain to code the "AI" of it though sadly.