Optimization of the airspace over Fujian and the operational adjustment of M503 route and its connecting lines is geared to meet the needs of air transport development between the Yangtze River Delta Area and Guangdong-Hong Kong-Macao Greater Bay Area, as well as of China’s southeast coast. It will optimize flight environment, ensure flight safety, and enhance support in thunderstorm season to improve flight regularity, so as to better serve passengers.