BEIJING, Dec. 18, 2020 An AG600 ''Kunlong'' amphibious aircraft flies over the sea off Qingdao, east China's Shandong Province, July 26, 2020. .China's indigenously developed AG600 large amphibious aircraft succeeded in its maiden flight over sea in Qingdao. (Credit Image: © Li Ziheng/Xinhua via ZUMA Press)