Making a "float" spell in JASS

I've searched the forums with no clear reply, so I'm asking this:


Is this ONLY possible to do on flying units? Because it clearly doesn't work on ground units.

If so, I tried to do this but it didn't work either:


Is there any workaround to this?

Add and remove the Medivh crowform ability from the unit. This will allow its flying height to be changed.

Add the medivh storm crow form and remove it promptly. See PitzerMike's compilation of ability tips in the Warcraft III ability guide for more info.