China’s independently developed ARJ21 regional jetliner takes a test flight at Daocheng Yading Airport in the Ganzi Tibetan Autonomous Prefecture in Southwest China’s Sichuan Province on July 12 in this photo released Thursday. Located 4,411 meters above sea level, it is the world’s highest-altitude civilian airport. The test verified that the ARJ21 is capable of operating in all high-plateau airports, and paved the way for airlines to use the aircraft to open more high-altitude routes, its developer, Commercial Aircraft Corporation of China, announced. Plateau airports refer to those airports with an altitude of more than 1,500 meters above sea level. China News Service