Junkers Ju 87 attack of the war. The Stukas attacked 11 minutes before the official German declaration of hostilities and hit the targets. The Ju 87s achieved complete success. The mission failed as the German Army delayed their advance allowing the Poles to carry out repairs and destroy all but one of the bridges before the Germans could reach them. A Ju 87 achieved the first air victory during World War II on the morning of 1 September 1939, when "" "Leutnant" Frank Neubert of I./StG 2 "Immelmann" shot down a Polish PZL P.11c fighter while it was taking off from Balice airfield;
Junkers marked on the J-9's landing gear wheel covers. The corrugated duralumin wing and fuselage "skin" introduced in the J-series became a trademark of Junkers aircraft built in the 1920s and '30s. Development continued during the course of World War I, including a growing (but troublesome) partnership with Fokker, as the "Junkers-Fokker Aktiengesellschaft". Several Junkers designs were licensed to Fokker during this period. The visual similarity of Junkers and Fokker aircraft during the next decade, especially after Reinhold Platz adapted some of the Junkers design concepts, but mostly crafted in wood for the Fokker designs' wing structures instead of the all-metal