A staff member shows the monitor of the flight attitude of an ARJ21-700 plane during a test flight in Dongying, east China's Shandong Province, Oct. 14, 2017. The Chinese-developed regional jetliner, which has the BeiDou navigation system installed, has successfully completed a test flight, the Commercial Aircraft Corporation of China (COMAC) said Saturday. (Xinhua/Ding Ting)