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 Ju 87 Secretary of State for Aviation Erhard Milch, feared that such high-level nerves and skill could not be expected of "average pilots" in the "Luftwaffe". Nevertheless, development continued at Junkers. Udet's "growing love affair" with the dive bomber pushed it to the forefront of German aviation development. Udet went so far as to advocate that all medium bombers should have dive-bombing capabilities, which initially doomed the only dedicated, strategic heavy bomber design to enter German front-line service during the war years — the 30-metre wingspan He 177A — into having an airframe design (due to Udet examining its design details in