Final answer:
The FD processes signals from navigation and flight instrument sets to produce steering commands that are performed through the roll, pitch, and yaw axes.
Step-by-step explanation:
The FD processes signals from navigation and flight instrument sets to produce steering commands that are performed through the roll, pitch, and yaw axes. The roll axis controls the rolling motion of the aircraft, the pitch axis controls the pitching motion, and the yaw axis controls the yawing motion. These axes are essential for the control and maneuverability of an aircraft.