Now that the new manacutters are ready, you can venture forth into the Aery.
This quest is available if you have completed the quest Ready to Fly.
Starting the Quest
Talk to Estinien in Ishgard to begin the quest.
Speak with Cid
Go outside and use the Aethernet Shard to go to the Skysteel Manufactory Aethernet Shard. Go northwest to the small stairway and go clockwise around the building. Go through the barred gate past Herewart and turn left, and talk to Cid. There will be a cutscene.
Use the Duty Finder or Duty Support to enter The Aery. Please see the The Aery Guide for a walkthrough.
After you complete the duty in The Aery and exit the area, there will be a cutscene. This one is important, so it is recommended to watch it either now or via the Unending Journey in an inn room.
Speak with Estinien
Talk to Estinien to complete the quest.
Unlock Flying in the Churning Mists
"Into the Aery" is the final quest for unlocking Aether Currents in the Churning Mists. If you have completed the other Aether Current quests and attuned to the Aether Currents in the field in this area, which you can find using the Aether Compass in Main Menu > Duty > Collection in this area, you will be able to fly in the Churning Mists.
Get a Manacutter
This quest rewards you with a Manacutter Key. Be sure to use it to add it to your list of available mounts.
Next Main Scenario Quest
After you complete the quest, talk to Estinien to accept the next quest: The Song Begins.