An ARJ21 arrives at Aihun Airport in Heihe City, northeast China's Heilongjiang Province, May 2, 2018. China's home-developed ARJ21 regional jetliner on Wednesday began to fly on new routes in northeast China's Heilongjiang Province, said its developer. The opening of new air routes with ARJ21 represent the model's commercial flight operations in the country's most northern and extreme cold region, said the Shanghai-based Commercial Aircraft Corp. of China (COMAC). (Xinhua/Ding Ting)