![A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command flies in the sky during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/d7bfb520520c4e239763e601e8bb3218.jpg)
A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command flies in the sky during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command flies in the sky during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/d7c37d7871484bb689315e5d0f294ba6.jpg)
A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command flies in the sky during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command takes off during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/9f7f4273c1c440d7b4c7d3299258ce60.jpg)
A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command takes off during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command flies in the sky during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/e580f4bc59c6435da371f046a208c5b9.jpg)
A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command flies in the sky during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![Maintenance men assigned to an aviation brigade of the air force with the PLA Northern Theater Command perform pre-flight inspections on a J-11B fighter jet prior to a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/32f0437f5d40427999642d178aa2474b.jpg)
Maintenance men assigned to an aviation brigade of the air force with the PLA Northern Theater Command perform pre-flight inspections on a J-11B fighter jet prior to a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![J-11B fighter jets attached to an aviation brigade of the air force with the PLA Northern Theater Command taxi on the runway during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/08a0fea5e697471cb170298a29bb793c.jpg)
J-11B fighter jets attached to an aviation brigade of the air force with the PLA Northern Theater Command taxi on the runway during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![J-11B fighter jets attached to an aviation brigade of the air force with the PLA Northern Theater Command taxi on the flightline during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/a07f62ba70584aa1a33c4c53870ed245.jpg)
J-11B fighter jets attached to an aviation brigade of the air force with the PLA Northern Theater Command taxi on the flightline during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![Pilots assigned to an aviation brigade of the air force with the PLA Northern Theater Command finish one-day training courses and prepare to climb down ladders from the cockpit of a J-11B fighter jet after a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/75e77a42b897456283360bdeceaa7d2d.jpg)
Pilots assigned to an aviation brigade of the air force with the PLA Northern Theater Command finish one-day training courses and prepare to climb down ladders from the cockpit of a J-11B fighter jet after a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command taxis on the runway after landing during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/e21b092fb8b044a5a0770f59aef2b761.jpg)
A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command taxis on the runway after landing during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command taxis on the runway after landing after the round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/cc7b68bec86049fcb41e80777cfbac30.jpg)
A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command taxis on the runway after landing after the round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command flies past the sun during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/beec609e5cea4c18933afa40a4c00ec5.jpg)
A J-11B fighter jet attached to an aviation brigade of the air force with the PLA Northern Theater Command flies past the sun during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)
![J-11B fighter jets attached to an aviation brigade of the air force with the PLA Northern Theater Command fly in formation during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)](http://www.ecns.cn/hd/2019/01/07/51e9aee8af14487c80d352f383f5a268.jpg)
J-11B fighter jets attached to an aviation brigade of the air force with the PLA Northern Theater Command fly in formation during a round-the-clock flight training exercise on January 3, 2019. (Photo/eng.chinamil.com.cn)