Liu Dong demonstrates a paper plane in Qingdao, East China's Shandong province, July 9, 2018. [Photo/VCG]

Folding paper planes in class, and reading aviation magazines after school, the then-11-year-old Liu Dong never imagined his childhood interest would turn into a lifetime career.

In 2007, Liu was unhappy with his work, and started to rethink his career path. It was then that paper plane, his childhood dream, knocked at his heart.

It was no easy task to turn his childhood interest into a profession, as Liu wanted his paper plane to be ingenious. Without readymade drawings, Liu created his own design based on childhood memories, thanks to his art degree from Qingdao University.

"I was exhausted," Liu said, recalling the 10 months he spent locked in his room designing the plane. He sold his first model to Singapore, and his business took off right after the launch of his store on Taobao, Alibaba's e-marketplace.

But Liu's business crashed soon after. So he attended a TV talent show for inventors in 2008 to secure free advertising. The 46-year-old became the biggest winner of the show, with teachers at youth centers introducing paper planes in science activities across campuses. The Aviation Administration Center of the General Administration of Sport even listed Liu's paper plane as special equipment for youth aerospace model competition.

Liu Dong makes paper planes. [Photo/VCG]

Aero modeling is a popular tech activity at primary and middle schools in China, with most schools using paper planes as a major teaching method. Traditional paper planes are too simple for teachers to illustrate basic aviation knowledge, and Liu's paper plane simulator perfectly solved the problem.

The paper plane simulator has adjustable flaperon, elevator, and rudder, enabling it to simulate various aerodynamic configurations; moreover, the paper plane requires no glue or tape, which is convenient and environmentally safe as well.

Liu's big moment came just after First Class at School, a large public welfare program covering primary and middle school students, was broadcast in 2013. "From barely one order we went to more than 200 models that single night," Liu said.

Schools around the country started to invite him to deliver lectures to students, even graduate students from China's top Tsinghua University became big fans of Liu's paper planes.

As the first person to mass retail paper planes in China, Liu earned 50,000 yuan ($7,475) that month, with the average price of a plane ranging from 0.5 to 2 yuan.

The aviation fan has sold 6 million paper flight simulators in the past five years, while the sales of surfing plane have risen to more than 10 million. "I am the top plane maker in the world, as none of my competitors has higher shipment," Liu said.

Liu Dong takes a photo of his paper plane. [Photo/VCG]