JOURFIXE

15 августа 1939 В Германии произошла одна из самых массовых авиакатастроф: при показательном бомбометании с пикирования в условиях низкой облачности в землю врезались 13 летящих друг за другом пикирующих бомбардировщиков Юнкерс Ju.87.

http://wapedia.mobi/en/Junkers_Ju_87?t=5.
All Stuka units were moved to Germany's eastern border in preparation for the invasion of Poland. On the morning of August 15, 1939, during a mass formation dive bombing demonstration for high ranking commanders of the Luftwaffe at Neuhammer training grounds near Sagan, 13 Ju-87 with 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 on that particular day the ceiling was too low and unexpected ground mist formed, leaving them no time to pull out of the dive.