A Chinese air force plane takes off to conduct drills in international airspace over the Sea of Japan, Dec. 18, 2017. The Chinese Air Force announced a roadmap for building a stronger modern air force in three steps. The building of a stronger modern air force is in line with the overall goal of building national defense and the armed forces, Lieutenant General Xu Anxiang, deputy commander of Chinese Air Force, said at a press conference on celebrating the 69th anniversary of the establishment of Chinese Air Force held in Zhuhai, south China's Guangdong Province, Nov. 11, 2018. (Photos: Xinhua)

A Chinese People's Liberation Army (PLA) air force formation conducts island patrols during training on April 26, 2018. The Chinese Air Force announced a roadmap for building a stronger modern air force in three steps. The building of a stronger modern air force is in line with the overall goal of building national defense and the armed forces, Lieutenant General Xu Anxiang, deputy commander of Chinese Air Force, said at a press conference on celebrating the 69th anniversary of the establishment of Chinese Air Force held in Zhuhai, south China's Guangdong Province, Nov. 11, 2018.

Chinese air force formation including H-6K bombers conduct island patrol in April 19, 2018. The Chinese Air Force announced a roadmap for building a stronger modern air force in three steps. The building of a stronger modern air force is in line with the overall goal of building national defense and the armed forces, Lieutenant General Xu Anxiang, deputy commander of Chinese Air Force, said at a press conference on celebrating the 69th anniversary of the establishment of Chinese Air Force held in Zhuhai, south China's Guangdong Province, Nov. 11, 2018.

A fighter plane of Chinese air force takes part in a regular patrol exercise on Dec. 11, 2017. The Chinese Air Force announced a roadmap for building a stronger modern air force in three steps. The building of a stronger modern air force is in line with the overall goal of building national defense and the armed forces, Lieutenant General Xu Anxiang, deputy commander of Chinese Air Force, said at a press conference on celebrating the 69th anniversary of the establishment of Chinese Air Force held in Zhuhai, south China's Guangdong Province, Nov. 11, 2018.

A People's Liberation Army (PLA) airforce J-10A fighter is seen during a training module in preparation for the International Army Games on July 11, 2018. The Chinese Air Force announced a roadmap for building a stronger modern air force in three steps. The building of a stronger modern air force is in line with the overall goal of building national defense and the armed forces, Lieutenant General Xu Anxiang, deputy commander of Chinese Air Force, said at a press conference on celebrating the 69th anniversary of the establishment of Chinese Air Force held in Zhuhai, south China's Guangdong Province, Nov. 11, 2018.

File photo shows the People's Liberation Army (PLA) Air Force conducting a joint combat patrol mission in the South China Sea. The Chinese Air Force announced a roadmap for building a stronger modern air force in three steps. The building of a stronger modern air force is in line with the overall goal of building national defense and the armed forces, Lieutenant General Xu Anxiang, deputy commander of Chinese Air Force, said at a press conference on celebrating the 69th anniversary of the establishment of Chinese Air Force held in Zhuhai, south China's Guangdong Province, Nov. 11, 2018.

A J-10 fighter jet of the Chinese People's Liberation Army (PLA) Air Force's August 1st aerobatics team is seen at an airport in northwest China's Xinjiang Uygur Autonomous Region, Aug. 16, 2018. The Chinese Air Force announced a roadmap for building a stronger modern air force in three steps. The building of a stronger modern air force is in line with the overall goal of building national defense and the armed forces, Lieutenant General Xu Anxiang, deputy commander of Chinese Air Force, said at a press conference on celebrating the 69th anniversary of the establishment of Chinese Air Force held in Zhuhai, south China's Guangdong Province, Nov. 11, 2018.

Two People's Liberation Army (PLA) airforce JH-7A fighter-bombers are seen during a training module in preparation for the International Army Games on July 12, 2018. The Chinese Air Force announced a roadmap for building a stronger modern air force in three steps. The building of a stronger modern air force is in line with the overall goal of building national defense and the armed forces, Lieutenant General Xu Anxiang, deputy commander of Chinese Air Force, said at a press conference on celebrating the 69th anniversary of the establishment of Chinese Air Force held in Zhuhai, south China's Guangdong Province, Nov. 11, 2018.