Trigger
Activation: None
set to: Repeatedly
Condition: !alive vehicle1
On Activation: see notes below
as per the activation, this would be the system that you use to get the supporting vehicles to the enemy
if its a chopper, then try this
On Activation: helo1 setfuel 1
and have the chopper set up in the following way
name it helo1, remove all its fuel, place it on the ground with decent clearance for takeoff
set its waypoints to wherever you need them, i would use a search and destroy waypoint for the attack area.
If the position of the attack is dynamic, eg changes, depending on where vehicle1 was destroyed for instance, then in the first waypoint's On activation box, place the following line
[helo1,x] setwppos getpos vehicle1
X being the number for the search & destroy waypoint
that'll do it for ya