cbradbury;
I was just looking at the C&C Mod objects. One of them is the DZ (Dead Zone) object:
"This object is intended to help mission designers "clean up" missions by removing aircraft from a mission when they are no longer needed.
Placement: Somewhere out of the way, preferably in the corner of a map. An airfield where you intend planes to land and disappear will also work. Give it the same color as the planes you want to remove.
- How it works: When planes of the same color as the object get within 1000m, they will pop out of existence at the rate of one every 5 seconds, regardless of altitude. If you want to remove large groups of planes, you should have them orbit the object at low level, or make repeated passes to make sure they disappear. Multiple objects can be used to widen the "Dead Zone".
- This object is intended to solve an old mission-builders' problem on maps like Berlin, where there is nowhere for bomber-streams, fighters, etc to go when they have completed their mission and are no longer needed. Rather than have them orbit in the corner or fly off the edge of the map, the mission builder can now simply remove them, thus saving FPS.
* The player's plane cannot be removed by the DZ object, though his AI wingmen can."
Not exactly what you're after but...