For many years, outside observers have wondered why many Chinese weapons look awfully like their US counterparts. These in China tend to come later after their American versions, with engineers from China strongly stating that any resemblance was coincidental.
Both China and United States have similar requirements for many weapons systems. And identical requirements can lead to identical outcomes.
Previously, China has constantly been accused of using its hackers and IRL spies to search for military technology. Since 1989, China has been under European arms embargo, and the only remaining way to acquire Western knowledge is to steal it. Lately, China was accused of hacking and stealing information on F-35 Joint Strike Fighter.
J-31 is a Chinese jet that looks like American F-35 Joint Strike Fighter. It was first seen in 2012, and bared strong resemblance with American fighters. The jet’s fast development period has led to some people suspecting that it relied heavily on stolen American technical information; with security activist Edward Snowden alleging that F-35 data was taken by Chinese cyber spies.
Next up is US C-17 Globemaster III. The jet is classified as a tactical heavy lifter. It can haul tanks to very distant regions from US. For instance, it is believed it can haul tanks from America all the way to Afghanistan. It is a very vital asset for U.S. military forces.
Chinese Y-20 heavy transport has almost the same functions with the C-17. Built by Xian Aircraft Corporation, the jet looks virtually similar with American C-17, even its vertical stabilizer. In this case, Chinese engineers admitted that they got some help from the Antonov design bureau, a manufacturer of aircraft based in Ukraine that specialized in making cargo and transport planes.
A Chinese tiexue.net website shows a lot of images that confirm that US and America have identical weapons.
Who knows beyond that? Only china can tell.