Mi-171Sh military transport helicopters attached to a search and rescue aviation brigade of the air force under the Chinese PLA Northern Theater Command stand by for takeoff during a Combat Search and Rescue (CSAR) training exercise.(eng.chinamil.com.cn/Photo by Zou Yuxi and Zhang Tianci)

北部战区空军运搜某旅近日开展搜救训练。图为米171直升机机队待命升空。（英文中国军网/邹於希、张天赐 摄）