Hey gadolinite, from what you say it doesn't sound like you're doing anything wrong as such. If the guy keeps missing though you might wanna up his skill level to be a GOD..!
I have had problems in the past where AI units ignore orders from non-AI units of lower rank sometimes... Check the A10s rank isn't higher than the player units rank... Just a thought...
I've used the following in the past to get an A10 to come in and smeg the crap outta target.
Bang an A10 on the map anywhere, and set its SPECIAL to flying. Then put a las-des unit (player) on the map near the thing you wanna hit. When you 'paint' the target and 'fire' the las-des, the A10 should come in and blow up the target... ;D
Draw backs to this method are:
a) no pretty take off from airfield for A10, (if you wanna see that)
b) depending on how long into the mish you are, depends on how long it will take for the A10 to hit the target. This is because the A10 continues to fly in the same direction as placed until called in. In theory it could be a looong way off the map when you do call it.
c) all of the above..!
What you could try is having the A10 in a holding pattern with two or more wayoints, one being a "cycle" type sync'd to a switch trigger that detects the las-des being fired. In theory you could do this with the <nearestObject> command.
So have the following in the trigger condition line:
nearestObject [player, LaserDesignator]
If this works then there should be nothing stopping you from having the A10 start at the airfield. Just have the A10 on the taxiway with no fuel with a WP on the vehicle of 'move' type (you can set the speed and status etc of the A10 at this WP). Sync this WP to the trigger as above, but with the following in the onAct field "planename" setfuel 1. then have one more WP set to Seek & Destroy/Destroy.
The plane will stay on the taxiway and not move (no fuel) until the las-des if fired. It will then get fuelled and move off to the S&D WP.
I haven't tried this so don't be too cheesed off if it doesn't work...