Ha ha,I have tried to larger the trigger area to 5000*5000,but the airplane fool again.
Even, I tried to use "radio Alpha" to control the airplane to drop Mk82, it also didn't work......
But thanks the same for your trying.
Now I'm about to doubt that is it a bug?
Well now I find something.The Mk82 just acts like a Hellfire.No targets,the AI won't fire.What's more,before firing a Mk82,the plane would do some preparetions like fly up then speed down.The AI won't fire if it thinks that the plane is not in the right behaviour,nor would the AI fire a Mk82 when it thinks the bomb will do NO damage to the enemy.
At last,I simply place a T72 and a AV-8B in the map,and remove all the weapons in the AV-8B EXCEPT the Mk82,the plane will get down and engage the T72 using its Mk82 just like a missle.