The innovative concept of remote tower operation is where air traffic controllers provide air traffic services to airports from a geographically separated virtual tower. Compared with the traditional tower, the remote tower has not changed the content and regulations of providing the airport with air traffic service. The major changes are infrastructure and technical systems, the resulting adjustment of operational processes and methods, and human factor ergonomic adaptation. Monitoring performance is foreseen as the most promising way to increase capacity and safety. However, the nature of task properties and potential human errors in tower control are not fully understood. The research objective is to analyze the possible human errors in tower control and find out tasks determined by visual scanning. We conducted semi-structured interviews with five experienced air traffic instructors with practicing certificates working at the CAFUC. The hierarchical task analysis (HTA) is used to analyze the critical operations of remote tower controllers. The systematic human error reduction and prediction approach (SHERPA) is used to analyze the possible human errors of each task throughout the entire process. Then we make a categorized analysis to collect tasks determined by visual scanning and describe the reason and influence factors for human errors in each task. We also interviewed design experts and conduct participatory design to put forward suggestions for preventing human errors, performance improvement of tower controllers, and the optimization of human-computer interaction in the future.