Let's assume we have a level 10 Arcanist, who has taken the School Understanding exploit, and chose the Air School. This will get her the Air Supremacy feature from the Air School.
I'm fairly sure that without using any arcane points, the arcanist would now be able to cast feather fall on herself at will.
Where I'm less sure, is that if she uses an arcanist point, can she now cast fly on herself at any point for the next minute? And presumably that fly spell would last for 10 minutes.