The area rule was discovered by Otto Frenzl when comparing a swept wing with a w-wing with extreme high wave drag[REF] while working on a transonic wind tunnel at Junkers works in Germany between 1943 and 1945.
Subsequent German wartime aircraft design took account of the discovery, evident in slim mid-fuselage of aircraft including the Messerschmitt P.1112, P.1106 and Focke-Wulf 1000x1000x1000 type A long-range bomber, but also apparent in delta wing designs including the Henschel Hs P.135.