Most probably the start of the massive 1938 German Air Rally. A reported 390 aircraft took part. In the left row are Fw 44 aircraft including D-EOQA and D-EGDU, third, which registration is listed as a Bü 131. Rangsdorf, south of Berlin, was opened as a sport airfield for the 1936 Olympics. The Bücker plant was located here. Lufthansa moved its flights from Tempelhof to Rangsdorf during WWII.
This photo was added on 26 April 2022, and has since been viewed 379 times.