Wing Rock Due to Aerodynamic Hysteresis

An analysis is presented using control theory concepts to show that aerodynamic hysteresis of the form of relay action can lead to lateral-directional limit cycle motions. These limit cycle motions are usually described in a colloquial sense as airframe wing rock. The aerodynamic details leading to wing-rock oscillations will vary with airframe configuration, and usually the exact description of the aerodynamic nonlinearity is difficult to obtain or predict. The purpose of the studies described herein is to promulgate a flight mechanics analysis technique which by virtue of its simplicity offers the analyst an insight into potential candidate aerodynamic mechanisms.