What references are used by a scheduler to prepare the duty schedule?

The correct choice encompasses essential references that a scheduler would rely on to create a duty schedule. Air Force Instructions (AFIs) provide overarching policies and procedures that govern various aspects of Air Force activities, ensuring compliance with higher-level mandates. Union contracts outline the specifics of employee rights, working conditions, and scheduling arrangements that must be adhered to within the framework of labor relations. Local guidance offers the unique directives and practices applicable to a specific unit or base, providing context that aligns with the local environment and mission requirements.

In combination, these references ensure that the scheduler is operating within the legal and regulatory framework, while also respecting the rights and agreements made with personnel. This foundation is crucial for fostering an effective, equitable, and compliant scheduling process within aerospace medical service or any related field.

The other choices involve references that are either not specific to the military context or do not directly relate to the unique responsibilities of a scheduler in an aerospace medical service environment. For example, operational instructions and national guidelines (in one option) may not have the localized specificity necessary for duty scheduling, while departmental handbooks and state laws (in another option) might not be fully applicable within the Air Force structure.