Analysis of the Effects of Higher Order Control Systems on Aircraft Approach and Landing Longitudinal Handling Qualities

摘要

The approach and landing longitudinal flying qualities data generated by Calspan using variable stability NT-33 aircraft combined with significant control system dynamics was analyzed. Three different approaches were used to determine the relationship between pilot ratings and the pilot workload, system sensitivity, and the system performance. An open-loop frequency response analysis showed that for a particular cross over frequency and phase margin (fixed performance), the phase angle (pilot workload) and slope of the phase curve (system sensitivity) at the crossover frequency correlated well with the pilot ratings. An optimum pilot lead time for pitch tracking, flight path angle tracking, and both pitch and flight path angle tracking tasks is determined by a closed-loop analog simulation using integral error squared as a performance measure. A correlation is found between pilot ratings and performance. An attempt is made to explain the landing task as a closed-loop pitch and flight path angle tracking task. The open-loop impulse response of the pitch attitude showed that the initial delay and the transient behavior of the pitch response have a direct impact on the pilot ratings, pilot induced oscillations, and comments. (Author)