Is this target padlock that allows you to highlight the icon of an airplane or tank once you are in range to see it? I didn't know if you tagged a tank from the air, then lost sight of it under the trees that the red box stayed visible. I though the box disappeared when you flew out of icon range. So for a tank you would have to be circling quite close or loose the lock.
Tank to tank enemy tanks don't show an icon so padlock does not work. Plane to plane, I've been told the con you tagged, the box shows through clouds so you can keep it from hiding there. I tend to agree since I ducked into a large cloud bank to drop out behind someone. He flew straight up into the cloud exactly where I was hidden and HO'd me.
Now if Hitech had the GV icon distance set out to 4.5k like I have mine set offline, yes it's devastating, 1 to 1.5k would be just as bad in the MA. So the current is what 800? At 800 if you can see the icon you don't need target lock if it's a tank. If it's a mobile flaker, you are screwed anyway.