Sailors aboard the guided-missile frigate Fushun (Hull 591) refuel a Z-9 ship-borne anti-submarine helicopter during a 6-day maritime realistic training exercise at an undisclosed sea area from March 5 to 10, 2018. They are assigned to a frigate flotilla of the navy under the PLA Northern Theater Command. (eng.chinamil.com.cn/Photo by Huang Liang)
