The rolling up of the vortex sheet shed from a finite aspect ratio wing into discrete vortices has been extensively investigated in the past. Most of these investigations have, however, considered wings having an elliptic loading.The early design charts of Silvertstein et al gave downwash angles for a variety of flapped and unflapped aerofoils by considering the trailing vortex sheet to be composed of discrete line vortices but ignored the rolling up process that takes place.