A Study of Longitudinal Controllability and Stability Requirements for Small General Aviation Airplanes.

摘要

Several aspects of small airplane longitudinal stability and control were examined by means of analysis and in-flight simulation experiments. The influence of various levels of static stability in the context of approach, landing, and climb tasks was studied, with particular emphasis on the effects of force gradient augmentation by means of downsprings. Cases in which spring force varied with elevator deflection or with angle of attack were considered in addition to the classical constant-force type. Constant-force or increasing force with up-elevator springs were favored when the preferred natural (no device) gradient was not available. Maneuvering stability tests focused on the effects of departure from linear force vs. normal acceleration characteristics, a local reduction in slope of 50 percent was detectable but considered to be acceptable. (Author)