How does an increase in dihedral angle affect an aircraft's stability?

An increase in dihedral angle enhances an aircraft's lateral stability, which refers to the aircraft's ability to resist rolling motions caused by gusts of wind or other external forces. When the wings of an aircraft are angled upwards from the horizontal in a dihedral configuration, the effect is that if the aircraft starts to roll to one side, the wing on that side will experience a lower angle of attack relative to the relative wind. This reduction in lift on the lowered wing naturally generates a moment that tends to return the aircraft to level flight.

Essentially, with a greater dihedral angle, the stabilizing effect during lateral disturbances is amplified. This design characteristic is especially beneficial for maintaining controlled flight under conditions where lateral stability is crucial, such as in turbulent air. In contrast, a smaller dihedral angle could lead to increased susceptibility to rolling motions, thereby compromising stability. Thus, the principle that supports the functionality of dihedral angle in enhancing lateral stability is firmly grounded in aerodynamic principles, making an increase in the angle a favorable design feature for enhancing stability.