Final answer:
During periods of reduced ATC services, the Flight Watch Service (FWS) can be filled by maintenance, supervisory, and administrative personnel, ensuring that essential services and safety are maintained in the airspace.
Step-by-step explanation:
During periods of reduced Air Traffic Control (ATC) services, the Flight Watch Service (FWS) may be filled by d. All of the above: maintenance personnel, supervisory personnel, and administrative personnel. This means that in times when ATC services are not fully staffed or are experiencing a shortage of air traffic controllers, other qualified personnel within the aviation facility may step in to ensure that the FWS continues to function effectively. These individuals are trained to provide necessary information and services to pilots in order to maintain safety and efficiency within the airspace.