What is necessary before any aircraft movement or engine start?

The requirement for signaling the crew chief before any aircraft movement or engine start emphasizes the importance of safety and coordination in ground operations. The crew chief is responsible for overseeing the safety of personnel and ensuring that all pre-flight protocols are followed. By signaling the crew chief, personnel can confirm that the area is clear, safety checks have been completed, and that all team members are aware of the impending movement or engine start. This step is critical in preventing accidents and ensuring that all operational procedures are adhered to before the aircraft is mobilized.

In contrast, while performing a systems check, clearing people from the vicinity, and turning on lights are important operational phrases, they generally follow the initial communication and confirmation with the crew chief. Each of those actions is part of the broader standard operating procedures that contribute to a safe environment, but initiating the process with the crew chief ensures that everything is managed systematically and that safety is prioritized right from the start. Thus, signaling the crew chief is the essential first step in the sequence of actions required for aircraft movement or engine start.