The following contains spoilers for Final Fantasy XV . Do not read if you don't want to know.
While Final Fantasy games all take on completely original stories with all new characters, there are some elements that often carry over from one game to the next. Moogles almost always appear in one capacity or another. The weapon options tend to fall into the same categories. And you can almost always get an airship to travel the map.
Is there an airship in Final Fantasy XV? Yes, there is, although it's not called that. It's called your car, the Regalia. There is a way to make it take to the air. However, unlike most Final Fantasy games, the airship doesn't simply come along as part of the main quest. To get the Regalia in the air you have to take certain optional steps. Here's the breakdown.
Take Down The First Two Imperial Bases
Following your encounter with Titan, the Regalia gets grabbed by the Empire, leaving you to either hoof it on foot, or take Chocobos wherever you need to go (Hint: use Chocobos). When it's found by Cindy, she tells you it's being held at an Imperial base. You have to infiltrate the base and take your car back. Shortly thereafter the game will pull you over on the side of the road to take down another one. By successfully beating each base you'll receive a unique item that you can't do anything with. They'll come in handy later. Much, much, later
Beat The Game
Once you've taken down the first two bases, you don't need to worry about anything until you get to the end of the game, and beat it. Beating the game doesn't actually do anything for you, but the last pieces of the quest to make the Regalia airborne don't unlock until you beat the game. Once you do, create a new save file. It will put you back at the last place you saved it, but it will recognize that you've beaten the game. Now, use Umbra to go back in time.
Find, And Defeat, the Formouth Garrison
Once you've beaten the game and returned to the past, check the world map. In the upper right-hand corner of the map, you'll see a gray block, that looks just like the way the other bases look on the map. Grab the Regalia and give it a drive by. As you pass by the base the first time, you'll get a brief scene of an airship flying overhead toward the base. This will open up the side quest. Now, just go to the tower next to the base, and trigger the infiltration.
Go See Cindy
After you beat all three bases and get another strange piece, take them to Cindy in Hammerhead. She'll install them on the Regalia, creating the Regalia Type-F. The F, we assume, stands for Flying. Now your car can take to the air. Be careful. Crashing into other cars while taking off or landing will destroy the Regalia. Once you're in the air, you're pretty much safe, however. Also, you now have infinite fuel, so there's little need to stop at gas stations. You'll also have free reign over the map, including areas that were not previously accessible from the ground.