Mechanical engineers offer maintenance service to airplanes to ensure flight safety

A mechanical engineer installs air conditioner system for an airplane at Urumqi Diwopu International Airport in Urumqi, northwest China's Xinjiang Uygur Autonomous Region, Jan. 21, 2020. Staff members of China Southern Airlines have fully prepared to offer maintenance service to airplanes, an effort to ensure flight safety during the Spring Festival travel rush. (Xinhua/Ding Lei)