I just got my ARC to level 15 but want to get to Ul'dah to start leveling a thaumaturge. I was told I'd get a quest to unlock airship travel at level 15 but I haven't seen anything yet. Is it automatic or is there an NPC in Gridania I need to talk to?

I completed my level 15 class quest as well, so just want to make sure I'm not missing anything.