Photographing China's backyard aviators

Jin Shaozhi's family, meanwhile, was so opposed to his ambitions that he had to sneak his plane out of town to conduct test flights: His relatives had conspired with the region's transport police to detain him if he ever set foot on the local airfield.

Some had encountered much more serious problems. Several had suffered potentially life-threatening crashes, and Su Guibin, 39, from Chaozhou, is still paralyzed from the waist down after colliding with a telegraph pole mid-flight in 2014.

Despite this, each of the aeronauts still burns with an infectious optimism. Seventy-three-year-old Jin declared to Xu: " I plan to keep improving my aircraft and fly until I'm 90—I will fly higher, further and safer!" Even bed-ridden Su told her cheerily that the first thing he planned to do after his recovery was to get back in the cockpit.

Optimism is not the only thing the aeronauts have in common. All were born before 1978, the year Deng Xiaoping initiated the reform and opening-up of China's economy, and in many ways they seem to encapsulate the generation that came of age just when China emerged from the Cultural Revolution to plunge headfirst into the sea of capitalism.

For Xu, the aeronauts embody that spirit of adventure and improvization that Deng Xiaoping, the father of post-Mao China, called "crossing the water while feeling for stones":

"I think one typical Chinese characteristic is being flexible and adaptable, of living with what you have and trying to get the best out of it. That is exactly what makes the aeronauts unique," she says.

At the same time, as Aeronautics in the Backyard captures so well, these by-your-bootstraps aviators also represent something universal:The feeling of watching the birds swooping effortlessly through the air, and dreaming of some day joining them. As they stare up at the infinite blue sky, our hearts yearn with them.

Aeronautics in the Backyard is now available for purchase via Amazon and other major outlets. For more information about Xiaoxiao Xu and her work, please visit xiaoxiaoxu.com