The dihedral effect is quantified by an instance of a derivative named for either control or this property, which is the change in rolling moment per change in sideslip angle. A "Dutch roll" may occur when the directional form of this property is weaker than its lateral form. The displacement between the center of gravity and the neutral point is called this property's margin. Military aircraft generally require computer fly-by-wire control systems since they (*) forego this property for maneuverability. The elevator is part of a set of components (10[1])named for this property that establish trim. For commercial aircraft, a vertical tailfin and a pair of horizontal tailplanes maintain this property (10[2])by damping displacements to pitch (10[1])and yaw. For 10 points, name this property of aircraft that return to equilibrium (10[1])after a perturbation. (10[2]-5[1]) ■END■