Hi, I need to make changes to an existing design of a model radio controlled aircraft to increase its lift to carry more payload. Pls confirm my ideas and any suggesstions would be really appreciated. Using wingtips to reduce induced drag and increase lift. Will a Dihedral affect lift in any way? Is there any advantage of using a twin vertical stabiliser tail design on lift? what is the advantage of a twin tail over the conventional one? Also among the wingtips pls suggest which of the below could be best suited for higher lift: Winglet, Wingtip fence, raked wingtip, blended wingtip. I would really appreciate any help on the above. Thanks!