Lateral (asymmetric) aerodynamics of aircraft have received comparatively little attention compared with longitudinal (symmetric) aerodynamics of aircraft. Up to the present time, understanding, supported by effective and extensive numerical methods, has been built up on the attached flow past wings, wing-body combinations, etc, in symmetric conditions. It is now a natural progression to assess how far some of the predictive techniques for symmetric conditions can be extended to asymmetric conditions. Some of the surface panel methods have been developed purely for the symmetric case and their extension to an asymmetric flow is not merely a routine matter. As a preliminary step, to build up some experience and understanding of asymmetric flows, it is investigated how the standard vortex lattice model for finite wings might be modified to calculate the rolling moment on a finite wing due to steady sideslip (i.e. Lv, Clβ) at low speeds.