I was trying to use the EntityAirChangeEvent but I couldn't find a scenario where it was being called neither with a cow entity or the player entity.

I was then told (on the plugin development section of the forums) that the event was being created but not being called. Below is the link I was shown which is where the problem is. 

https://hub.spigotmc.org/stash/projects/SPIGOT/repos/craftbukkit/browse/nms-patches/Entity.patch#434-440