Troops prepare for a military parade at Zhurihe training base in North China's Inner Mongolia autonomous region, July 30, 2017. The parade was held to celebrate the 90th anniversary of the founding of the Chinese People's Liberation Army.

Twenty-four helicopters fly in the formation of the number "90" symbolizing the epic journey of the People's Liberation Army (PLA) in 90 years during a military parade at Zhurihe training base in North China's Inner Mongolia autonomous region, July 30, 2017.

Helicopters fly in the formation of "Bayi", the founding date of People's Liberation Army (PLA) during a military parade at Zhurihe training base in North China's Inner Mongolia autonomous region, July 30, 2017.

Air combat groups of the People's Liberation Army, including early-warning planes, bombers, transport aircraft, refueling aircraft, carrier-borne aircraft and fighters on Sunday fly over the Zhurihe military training base in North China in the Army Day parade. 

Air combat groups of the People's Liberation Army, including early-warning planes, bombers, transport aircraft, refueling aircraft, carrier-borne aircraft and fighters on Sunday fly over the Zhurihe military training base in North China in the Army Day parade.