What designation is given to a pilot assigned to duty during a flight?

The designation given to a pilot assigned to duty during a flight is "Flight Crewmember." This term encompasses all individuals on board who are responsible for the operation of the aircraft and includes pilots as well as flight engineers or any other designated individuals involved in the operation and safety of the flight.

In the context of aviation, a flight crewmember refers to those actively participating in the conduct of a flight, ensuring that all necessary tasks are carried out for safe and efficient operations. This designation allows for a comprehensive understanding of the roles played by various members of the crew in flight operations.

While terms like "Pilot in Command" specifically refer to the individual responsible for the overall operation of the aircraft, "Flight Crewmember" provides a broader classification that includes the entire flight crew. Therefore, even though "Pilot in Command" is a critical role, it does not encompass the entire flight crew. Hence, "Flight Crewmember" is the correct designation that captures the collective responsibility of those assigned to duties during flight.