XINXIANG, July 23 -- At 17:00 on July 23, three Z-20 helicopters dispatched by an airborne assault brigade of the 83rd Group Army under the PLA Central Theater Command took off upon receiving order and flied to Huixian County, Xinxiang City in northern Henan province. In the airspace of two towns in Huixian County, the three helicopters dropped multiple kinds of rescue materials and equipment to support the anti-flood efforts of the local people.