What does HALF BANK limit concerning the Flight Director?

The HALF BANK mode is a feature in the Flight Director system that limits the bank angle commands for turns during flight. Specifically, when activated, it reduces the maximum bank angle to 15 degrees. This is particularly useful during various flight phases, such as takeoff and approach, to promote safe and controlled maneuvers by preventing excessive bank angles.

By limiting the bank angle, the HALF BANK feature helps maintain a smoother flight path, enhances the aircraft's stability, and reduces pilot workload, particularly in busy airspace or during critical phases of flight. This level of control is essential for maintaining safety and adherence to operational procedures, ensuring that pilots can effectively manage the aircraft within safe operational limits.

While the other choices suggest higher bank limits, HALF BANK is specifically designed to cap the bank angle at 15 degrees, making it the correct answer in the context of the question regarding the limitations it imposes on the Flight Director's commands.