Your use case doesn’t benefit from your own data. There’s nothing you can do that doesn’t require a direct interaction from the server.

I write an audio recording app, and in my app, users have most to gain from their own data. For most people, syncing is basically an afterthought. In this use case, the ability of having your recordings in your phone is the most important thing.

The difference here lies that in my app, the user generates all the valuable data themselves. In your app, nothing valuable can happen without communication with the airline.