Airborn takes place in a kind of alternate dimension of the past, where airships rule the transportation industry rather than regular ships—you know, the kind that travel on water. Picture a maritime steam-punk version of Downton Abbey.
The societal values line up with pseudo-Victorian principles as well. Kate is stuck wearing totally inappropriate clothing for a tropical island most of the time, because heaven forbid we catch a glimpse of her ankles. She's also a fledgling feminist in a time when women are very obviously considered second-class citizens, as is Matt who wasn't fortunate enough to be born into money.
More specifically though, our story takes place either on the airship Aurora—which Matt has an unhealthy attachment to—or on an uncharted island in the middle of the Pacific Ocean (which in our story is called the Pacificus). Both of these locations, as well as the limited technology of the age, have the very important effect of isolating everyone from the world around them. When they're in the air they are too far out from land for anyone to hear a distress call, and when they're shipwrecked they are very much left to their own devices if they ever want to go home.
These two settings allow for unlikely heroes to arise: Cue Matt, the Intrepid Cabin Boy who saves the day.
The remoteness of our setting also makes the story more credible. If someone told you they'd just discovered a new species like the cloud cat, wouldn't you be a tad skeptical about such a creature going unnoticed in the age of Google Street View, cell phones, and the NSA? So by creating an alternate universe that is set in the past, our story becomes more believable. Mind = blown, right?