The handling qualities of airplanes have been a subject of considerable interest and concern throughout the history of piloted flight. The Wright Brothers were successful in achieving the first powered flight in large measure because they provided adequate flying qualities for the task at hand. As they became capable of flights of longer duration, they altered the handling qualities of their flying machine to improve piloting performance and to accomplish the expanded tasks. They maintained, throughout, a balance between the amount of stability (or instability) of their airplane in flight and the pilot’s ability to control its movements; they achieved a balance among the airplane’s stability, the airplane’s controllability, and the pilot’s capability. “Handling qualities” represent the integrated value of those and other factors and are defined as “those qualities or characteristics of an aircraft that govern the ease and precision with which a pilot is able to perform the tasks required in support of an aircraft role.” [1] From this definition, it is clear that handling quality is characteristic of the combined performance of the pilot and vehicle acting together as a system in support of an aircraft role. As our industry has matured in the 82 years since the first powered flight, the performance, size, and range of application of the airplane have grown by leaps and bounds. Only the human pilot has remained relatively constant in the system. In the beginning, the challenge was to find the vehicle which, when combined with the inexperienced pilot-candidate, could become airborne, fly in a straight line, and land safely. Longer flights required turns, and ultimately there were additional tasks to be performed. As greater performance capability was achieved, the airplane was flown over increasingly greater ranges of altitude and speed, and the diversity of tasks increased. The continuing challenge was—and still is—to determine what characteristics an airplane should have so that its role can be achieved in the hands of a relatively constant pilot. This challenge has been difficult to answer; the problem is that the quality of handling is intimately linked to the dynamic response characteristics of