Junkers Ju 87 near Sagan, 13 Ju 87s and 26 crew members were lost when they crashed into the ground almost simultaneously. The planes dived through cloud, expecting to release their practice bombs and pull out of the dive once below the cloud ceiling, unaware that the ceiling was too low and unexpected ground mist formed, leaving them no time to pull out of the dive. On 1 September 1939, the Wehrmacht invaded Poland, triggering World War II. "Generalquartiermeister der Luftwaffe" records indicate a total force of 366 Ju 87 A and Bs were available for operations on 31 August 1939. The first
Junkers J 2 fuselage framing, primarily as an engineering exercise, were finished shortly before the end of 1916. It is also thought that the contrasting promise of the advanced, low drag features of the Junkers monoplane aircraft designs, versus the Junkers firm's usage of experimental non-traditional sheet metal materials, and the firm's habit of almost constant experimentation obstructing any future hope of producing its advanced designs for the "Luftstreitkräfte", compelled "IdFlieg" to create the "Junkers-Fokker Aktiengesellschaft", abbreviated as "Jfa" and pronounced as if spelled "iefa" in German, on 20 October 1917, to allow Anthony Fokker, who even flew one of the J 2