Junkers Ju 87 below 3g and had lasted no longer than three seconds. In a crouched position, pilots could withstand 7.5g and were able to remain functional for a short duration. In this position, Junkers concluded that ⅔ of pilots could withstand 8g and perhaps 9g for three to five seconds without vision defects which, under war conditions, was acceptable. During tests with the Ju 87 A-2, new technologies were tried out to reduce the effects of g. The pressurised cabin was of great importance during this research. Testing revealed that at high altitude, even 2g could cause death in an unpressurised cabin
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