The Influence of Bobweights and Downsprings on Flying Qualities

Control-system bobweights and downsprings are quite often used in general aviation airplanes to improve longitudinal static stability at aft c.g. positions. However, these devices can also have strong and usually undesirable effects on the airplane's dynamic behavior. These important effects are reviewed and discussed. In addition, guidance is provided as to how some of the undesirable characteristics can be minimized by careful design.