Analysis Of Several Handling Quality Topics Pertinent To Advanced Manned Aircraft

This report presents the results of analytical studies of a variety of handling quality topics related to advanced manned aircraft.

Simulator study of coupled roll-spiral mode effects on lateral-directional handling qualities.

During the 16 glide flights of the M2 -F2 lifting body vehicle, severe lateral pilot-induced oscillations occurred on three occasions in the low - angle of -attack, final-approach, preflare situation. These oscillations were analyzed qualitatively to determine the type and similarity and by a systems analysis to determine the root cause. The analysis was complemented by a piloted simulator study, which verified the results. The systems analysis revealed the presence of a coupled roll-spiral mode which caused the pilots to generate a closed-loop lateral instability in the low-angle -of -attack, preflare flight region. A systems analysis, a piloted simulator study, and flight data showed that the addition of a fixed center fin lessened the pilot-induced-oscillation tendencies in the critical flight region.

Aeronautical engineers concerned with the analysis of aircraft dynamics and the synthesis of aircraft flight control systems will find an indispensable tool in this analytical treatment of the subject. Approaching these two fields with the conviction that an understanding of either one can illuminate the other, the authors have summarized selected, interconnected techniques that facilitate a high level of insight into the essence of complex systems problems. These techniques are suitable for establishing nominal system designs, for forecasting off-nominal problems, and for diagnosing the root causes of problems that almost inevitably occur in the design process. A complete and self-contained work, the text discusses the early history of aircraft dynamics and control, mathematical models of linear system elements, feedback system analysis, vehicle equations of motion, longitudinal and lateral dynamics, and elementary longitudinal and lateral feedback control. The discussion concludes with such topics as the system design process, inputs and system performance assessment, and multi-loop flight control systems. Originally published in 1974. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

The present study is an attempt to make an assessment of the influence of wind shear on the longitudinal motion of airplanes. It was assumed that the wind is completely horizontal and its speed varies linearly with altitude. It is shown quantitatively that both glide and climb performance are influenced by wind shear and that trimmed flight at constant airspeed, attitude, and with fixed controls is along a parabolic path relative to the ground. The problem of the landing approach in a wind shear is examined in some detail. Small disturbance theory indicates no wind-shear effect on the short-period motion and the time for the phugoid to damp to half amplitude but the phugoid frequency and damping ratio vary considerably with wind shear. A nondimensional quantity which depends on the wind shear and airspeed is shown to be a fundamental parameter influencing the longitudinal dynamic behavior of the airplane.