A visitor looks at China's CH-4 unmanned aircraft on display at Aviation Expo China 2013 in Beijing
A visitor looks at China's CH-4 unmanned aircraft on display at Aviation Expo China 2013 in Beijing September 25, 2013. The 15th biennial aviation event kicked off today with representatives from international aviation companies, including Boeing, Airbus and COMAC, taking part in the expo.
REUTERS/Kim Kyung-Hoon (CHINA - Tags: TRANSPORT MILITARY BUSINESS)