Cheng Lingfei's helicopter was much bigger than the one which Zhao Yu had taken last time.
The airflow caused by the propellers blew away most of the stuff on the rooftop, and the sound was tremendous. When Zhao Yu climbed up the ladder to the top of the building, he could hear nothing but the roar of the propeller.
Cheng Lingfei was climbing into the helicopter, and Liu Guangxing, the hacker was helping her.
The front of the helicopter was facing Zhao Yu, and he could clearly see clearly that the pilot was a woman. Even though she was wearing sunglasses, Zhao Yu recognized that the female pilot was He Yubing, the killer.
Cheng Lingfei had been careful to come up with a strong back-up plan. No wonder she was so confident just now! Even if the police surrounded the house, she could fly away.