Chen Xiulin, when in his 20s, flew a military plane over areas where China had conducted its first nuclear missile test in 1966, to collect some air samples.

But back then he didn't realize that one day he would take a route that's rather different for a People's Liberation Army aviator - that of a sculptor.

The 78-year-old Weifang native, from eastern China's Shandong province, is now working day and night to finish a set of bronze sculptures for the 2015 Milan World Expo. His work at the event to be held in May will depict scenes from China's trade and cultural exchanges with other parts of the world along the ancient Silk Road.