J-10 fighter jets attached to an aviation brigade of the air force under the PLA Southern Theater Command taxi on the runway to their parking spot after completing a round-the-clock flight training exercise on March 26, 2019. Such "two-on-two" and "two-on-one" free air-to-air combats were carried out during the training to improve the all-weather combat capability of pilots. (Photo:eng.chinamil.com.cn)

J-10 fighter jets attached to an aviation brigade of the air force under the PLA Southern Theater Command taxi on the runway to their parking spot after completing a round-the-clock flight training exercise on March 26, 2019. Such "two-on-two" and "two-on-one" free air-to-air combats were carried out during the training to improve the all-weather combat capability of pilots. (Photo:eng.chinamil.com.cn)

Two J-10 fighter jets attached to an aviation brigade of the air force under the PLA Southern Theater Command taxi to the ramp at a military airfield before takeoff for a round-the-clock flight training exercise on March 26, 2019. Such "two-on-two" and "two-on-one" free air-to-air combats were carried out during the training to improve the all-weather combat capability of pilots. (Photo:eng.chinamil.com.cn)

Two J-10 fighter jets attached to an aviation brigade of the air force under the PLA Southern Theater Command taxi to the ramp at a military airfield before takeoff for a round-the-clock flight training exercise on March 26, 2019. Such "two-on-two" and "two-on-one" free air-to-air combats were carried out during the training to improve the all-weather combat capability of pilots. (Photo:eng.chinamil.com.cn)

A J-10 fighter jet attached to an aviation brigade of the air force under the PLA Southern Theater Command takes off for a sortie during a round-the-clock flight training exercise on March 26, 2019. Such "two-on-two" and "two-on-one" free air-to-air combats were carried out during the training to improve the all-weather combat capability of pilots. (Photo:eng.chinamil.com.cn)

A J-10 fighter jet attached to an aviation brigade of the air force under the PLA Southern Theater Command takes off for a sortie during a round-the-clock flight training exercise on March 26, 2019. Such "two-on-two" and "two-on-one" free air-to-air combats were carried out during the training to improve the all-weather combat capability of pilots. (Photo:eng.chinamil.com.cn)