A long history of cooperation between China and Boeing forms the basis for today's extensive network of working together relationships in the People's Republic of China. Pilot, maintenance and management training in China support the operation of Boeing airplanes. In the same cooperative spirit, Boeing has developed advanced field services, logistics and technical support throughout the country, while also working together with China to advance air traffic management and aviation safety. In addition, several factories produce major assemblies and parts for Boeing airplanes. There are also joint ventures for composite manufacturing, airplane modification and repair, and spares. There are now over 3,300 Boeing airplanes flying worldwide that include major parts and assemblies built by China.