What is required of the pilot in relation to the autopilot during operation?

The requirement for the pilot to be seated at the controls during autopilot operation is critical for safety and operational effectiveness. This ensures that the pilot remains in a position to take immediate control of the aircraft if necessary. Autopilot systems can manage flight paths and maintain altitude, but they do not replace the need for situational awareness and the ability to respond quickly to unexpected situations. By being seated at the controls, the pilot is prepared to intervene as needed, which is essential for flying with an autopilot, especially in changing conditions or during potential emergencies.

The other options do not align with standard operating procedures and safety protocols. For instance, remaining unbuckled can lead to injury during turbulence or sudden maneuvers, and being in a resting position contradicts the need for alertness and readiness to take control. Similarly, neglecting to check instruments can result in a lack of situational awareness, which can be detrimental to flight safety. Thus, being seated at the controls is not only a procedural requirement but also a fundamental aspect of being a responsible pilot while the aircraft is under autopilot operation.