Class forms the primary division separating strata of society in Airborn. Through the contrast between Matt’s and Kate’s lives and mindsets, the novel demonstrates the way that access to wealth shapes how one sees and interacts with the world. Matt, from a poor family, begins working full time at age 12, after the death of his father leaves him the primary provider for his mother and sisters. Kate, by contrast, is financially privileged and occupies the finest stateroom on the Aurora during her travels. They share an interest in airships and a desire for adventure, and those shared interests, along with Kate’s lack of snobbery, allow them to transcend enough of their differences to forge a friendship.

Still, the difference in their classes creates significant external and internal boundaries between them. Wanting to solidify their friendship, Kate asks Matt to refer to her by her given name, Kate, instead of calling her Miss de Vries. When Matt refuses, pointing out that he would get in trouble if he were overheard, Kate scoffs: “‘Silly rules.’ ‘People like you invented them. Not me.’ ‘Good point,’ she said appreciatively, a thoughtful crease in her brow. ‘Really good point’” (98). Kate’s desire to set aside rules meant to enforce class boundaries shows her open-mindedness, and her response to Matt pointing out who makes and enforces those rules shows her to be willing to consider those with less class privilege than her as authorities on matters of classism.