Su Bin pleaded guilty in 2017 to conspiring to steal technical data related to the C-17 from Boeing and the US Air Force.
That data likely was used to build the Xian Y-20, China's large transport aircraft, nicknamed the "Chubby Girl." As Garrett M. Graff notes in Wired, Su helped pilfer about 630,000 files related to the C-17.
Whether China used information about the C-17 to build the Y-20 is unclear — Beijing has denied stealing US technology for its weapons systems — but the similarities are apparent, from the nose to the tail stabilizer, as Kyle Mizokami points out in Popular Mechanics.
The Y-20 has a smaller empty weight and payload than the C-17, Popular Mechanics reported in 2016, but the Y-20 is the largest transport aircraft in production. The Chinese military lacked a large transport carrier prior to the development of the Y-20, making it difficult to quickly mobilize large numbers of supplies and troops to battlefields or disaster areas, Wired reported in 2012.
"Just because something looks somewhat similar doesn't mean it has equivalent capabilities," Kliman cautioned, particularly where human capability is concerned.
"It's not the technology alone. It's the quality of the pilots in a fighter airplane. It's the quality of the systems that are feeding the aircraft information," Kilman said.
China hasn't fought a foreign war since the brief Sino-Vietnamese War in 1979. US service members and systems have much more battlefield experience than Chinese forces.
"The [People's Liberation Army] has made a long-term effort to improve its human capital, including through training but also through education ... but at this point, the US, our pilots, our operators get, certainly, the real-world experience," Kilman said.