Does target designation override what targets are normally valid for a missile/rocket?

Solution 1:

Yes, with laser designation aircraft can be targeted by weapons which normally lock on ground vehicles and equipment:

  • Javelin
  • Guided Shell (tank upgrade)
  • Guided Rockets (heli upgrade)

As a side note, MAV even though it's airborne, is considered equipment, not air vehicle. So you can down it with guided missiles even without laser designation.

Example with tank guided shell: