Catapult should be able to target air with artillery.

[newbcake3]

scron2 if you havent figured it out yet they just arbitrarily chose what can and cant hit air units. it has nothing to do with logic

mines hit air units
shockwave hits air units
antigravity tank plasma shot hits air units
light tanks rocket spray hits air units
hunter tank main cannon hits air units
demon tank ult hits air (which is conveniently a lesser version of titans e skill which doesnt hit air)
sky fortress's carpet bombs somehow hit air units
titans q stun hits air units...

anyways theres no real logic here just random skills were decided to hit air and some were not, i wouldnt bother arguing