I'm trying to find an animated movie I watched a long time ago, but I only remember one specific scene.
There’s a girl standing by something like a large window, looking out at big turbines or propellers. They seem to be inside some kind of massive airship or dirigible. I think the ground below might have been toxic or uninhabitable, so people were living in the air (or maybe they were just traveling, I’m not completely sure).
Then a boy shows up, they talk briefly, and suddenly the turbines outside the window get destroyed during an attack.
That’s all I can remember. Does anyone know what movie this could be?