Zhongnan Transmission Machinery Works of Changsha Aviation Industry is a professional manufacturer of aircraft engine gear and reductor under the leadership of China Aviation Industry Corporation Ⅱ. It is a state-owned super large enterprise, with the employees of 2900, an area of 420000 square meters, the fixed assets of 450 million Yuan. It passed the quality certification of ISO9001 in 1994 and ISO9001:2000 in 2003. Since the reform and open policy has been adopted in China, the Factory gives full play to the advantages of the advanced aviation industry technology, high level talents and advanced equipment to vigorously develop the civilian industry products. It has developed successfully six series products, i.e. the gearbox of the construction vehicles, marine gearbox, automobile gear, the precision gears in the mine machinery, textile machinery, steel wire rolling machine, tobacco machine, railway locomotives etc. and the special reductor.