J-10 fighter jets attached to an aviation brigade of the air force under the PLA Northern Theater Command taxi in close formation on the flightline before takeoff for a recent penetration flight training exercise. (eng.chinamil.com.cn/Photo by Yang Pan)

J-10 fighter jets attached to an aviation brigade of the air force under the PLA Northern Theater Command taxi in close formation on the flightline before takeoff for a recent penetration flight training exercise. (eng.chinamil.com.cn/Photo by Yang Pan)

J-10 fighter jets attached to an aviation brigade of the air force under the PLA Northern Theater Command taxi in close formation on the flightline before takeoff for a recent penetration flight training exercise. (eng.chinamil.com.cn/Photo by Yang Pan)

Pilots assigned to an aviation brigade of the air force under the PLA Northern Theater Command have pre-flight communications prior to a recent penetration flight training exercise. (eng.chinamil.com.cn/Photo by Yang Pan)

Pilots assigned to an aviation brigade of the air force under the PLA Northern Theater Command walk out of the runway after completing a recent penetration flight training exercise. (eng.chinamil.com.cn/Photo by Yang Pan)

Ground crews assigned to an aviation brigade of the air force under the PLA Northern Theater Command load rockets onto a J-10 fighter jet prior to a recent penetration flight training exercise. (eng.chinamil.com.cn/Photo by Yang Pan)