Wang Qiang sits in one of his hand-built light aircraft near his home in Cixi, Zhejiang province. The 41-year-old could not explain why he was so compelled to build aircraft, but said flying is "my dream, my joy; it's pretty much my life.[Photo provided to chinadaily.com.cn]

Photographer Xiaoxiao Xu travelled across China documenting the impoverished farmers striving to build their own aircraft, Dominic Morgan reports.

At 200 meters in the air, terror gripped Xiaoxiao Xu. She was sitting in the back of a rickety autogyro that her pilot, a baby-faced 42-year-old from rural Zhejiang province named Xu Bin, said he had designed and built himself, and she had just made the mistake of looking down.

I felt the wind through my hair and saw the houses, mountains, fields and lakes passing by below my feet, Xu recalls in her recently published book Aeronautics in the Backyard. I started to picture how exactly we were going to crash.

But then I spotted Xu Bin looking down below with the curiosity of a little boy. He was gleaming with intense happiness. I began to appreciate just how much enjoyment he gets out of flying, she continues. My fear faded, and I looked out to enjoy the view with him.

This combination of joy, wonder and just a hint of madness runs through Xu's new book, an uplifting collection of tales and photographs from her experience searching out China's rural dreamers who, against all odds, are taking to the skies in their own hand-built aircraft.

Xu's adventure began on a quiet afternoon in April 2014 at her home in Amsterdam, when an article titled "Air Castles" in the Dutch newspaper Volkskrant caught her eye.

"The article was about how some people in China were building their own aircraft," Xu tells China Daily via e-mail. "The images accompanying the article showed the most bizarrely designed airplanes. I was immediately fascinated by the rich imaginations of these people and the contrast between their romantic pursuit and their poor material existence."

Xu had spent most of her career photographing modern China, the country she left as a 15-year-old to move to the Netherlands, and she quickly decided to make the DIY aviators her next project.

However, as soon as she began her initial research for the project, Xu ran up against a daunting obstacle:How do you track down a group of farmers with no internet presence in a country of 1.4 billion people?

Faced with such a seemingly intractable problem, many people would have chosen quietly to concede defeat and move on. But much like the subjects she was seeking out, something drove Xu to take a leap of faith.

"I found some newspaper articles about them, what their names were and where they came from, and with this basic information I went to China," she says.

Armed with her list of names, Xu flew out to China in January 2015. Starting in southern Guangdong province, she threw herself into a gruelling, slightly frantic manhunt, travelling from village to village by train and juddering rural buses.