Core Points - The fifth runway at Guangzhou Baiyun Airport has commenced its flight calibration tasks, marking a critical milestone in the airport's Phase III expansion project [1] - The new runway is designed to 4E standards, measuring 3,600 meters in length and 45 meters in width, located 1,530 meters east of the existing East No. 2 runway [1] - The Central South Air Traffic Management Bureau has implemented a "dual tower" coordination system for air traffic control, enhancing operational efficiency and safety during the calibration flights [1][2] Group 1 - The flight calibration tasks are expected to last approximately 20 days, during which communication, navigation, and lighting facilities of the new runway will be thoroughly tested [2] - The dual tower system includes a new second tower responsible for low-altitude monitoring and landing procedures, while the existing first tower oversees overall command [1][2] - This marks the first significant operational task for the newly constructed second tower, indicating a new phase of collaborative operations at Guangzhou Baiyun Airport with "five runways and dual towers" [1]