According to federal regulations, who is considered a flight crewmember?

The correct answer is that a flight crewmember includes the engineer, navigator, or pilot assigned to duty. This designation stems from federal regulations, which define flight crewmembers as those individuals who perform essential tasks necessary for the operation of an aircraft during flight.

Each role contributes specific skills and responsibilities that are crucial for the safe and efficient operation of the flight. The pilot in command is the primary authority in the cockpit and responsible for the overall operation of the flight, while the flight engineer and navigator play supportive but vital roles. The flight engineer is responsible for monitoring aircraft systems and assisting the pilot, while the navigator ensures that the flight follows its intended route.

In contrast, the other options do not accurately reflect the comprehensive definition provided by regulations or ignore critical roles operating within the airspace. Only the pilot in command, cabin crew, or all operational staff do not encompass the full scope of individuals contributing to the flight's safe operation in the cockpit. Understanding that various roles come together as part of the flight crew helps emphasize the collaborative nature of aviation operations.