Helicopters of the Chinese People's Liberation Army (PLA) perform aerobatic maneuvers on Sept 15 during a flight show at the China International Helicopter Exposition, which runs from Sept 15 to Sept 18 in North China's Tianjin municipality. The expo is the first of its kind in Asia. More than 200 companies from over 20 countries and regions are attending. The expo will be open to the public from Sept 17 to Sept 18. [Photo/Xinhua]

Helicopters of the PLA perform aerobatic maneuvers on Sept 15 during a flight show at the China International Helicopter Exposition, which runs from Sept 15 to Sept 18 in North China's Tianjin municipality. [Photo/Xinhua]