She shares this recurring fantasy with the self-taught aviation enthusiasts who fill her delightful book, Aeronautics in the Backyard.

The eight men she photographed have little to no formal training in aeronautics. They are farmers, barbers, and carpenters with nothing more than a deep love of flight and a knack for cobbling together airplanes and gyrocopters. Most learned what they know from books and magazines, and happily pour time and money into contraptions that may not actually fly. And not one of them minds at all if people find them odd.

"The thing I like the most about the aeronauts is that they dare to be different," Xu says. "They don't care about the risks, the chance of failure, or what other think about them. They have a free mind whether or not their planes succeed in lifting off."