Which is a definition of the term "crewmember"?

The term "crewmember" is defined as a person assigned to perform duty in an aircraft during flight time. This definition encompasses a range of roles, including pilots, flight attendants, and any other individuals whose responsibilities are directly related to the operation and safety of the flight while it is in the air. Crewmembers are integral to the safe conduct of flights, ensuring that all operational protocols and safety measures are followed.

The other options describe functions or roles that might be associated with aviation but do not fit the definition of "crewmember." For instance, operating aircraft maintenance equipment is crucial for the overall operation of the aircraft, but it does not involve direct duty during flight time. Similarly, scheduling flights and overseeing cargo loading are essential activities that support airline operations but are not classified as duties performed by a crewmember during flight. Understanding these distinctions is key in the aviation industry, emphasizing the specific responsibilities tied to flight operations and crew safety.