Aircraft that look alike need not have been copied directly from one another. The Spitfire example leads to a discussion of designers using published research on wing sections, including NACA's catalogues and British studies from the 1920s and 1930s. The Royal Aeronautical Society is mentioned as one route through which such work circulated. Designers choosing from similar research and fitting the same Merlin engine could arrive at comparable forms. Shared technical knowledge and design constraints therefore need consideration before treating resemblance as proof of copying.
Notable Point · 2:17:31-2:18:54
Shared wing research and convergent aircraft design
Published wing research and common engine choices can explain similar aircraft shapes without establishing that one design directly copied another.