A J-11 fighter jet attached to an aviation brigade of the air force under the PLA Northern Theater Command flies through a mountainous region during a flight training exercise on February 17, 2020. (eng.chinamil.com.cn/Photo by Wang Jingwen)

A J-11 fighter jet attached to an aviation brigade of the air force under the PLA Northern Theater Command flies through a mountainous region during a flight training exercise on February 17, 2020. (eng.chinamil.com.cn/Photo by Wang Jingwen)

A J-11 fighter jet attached to an aviation brigade of the air force under the PLA Northern Theater Command flies through a mountainous region during a flight training exercise on February 17, 2020. (eng.chinamil.com.cn/Photo by Wang Jingwen)

A J-11 fighter jet attached to an aviation brigade of the air force under the PLA Northern Theater Command flies through a mountainous region during a flight training exercise on February 17, 2020. (eng.chinamil.com.cn/Photo by Wang Jingwen)