Junkers setbacks with crashes of prototypes in 1937 and 1938. Further refinements enabled certification in 1939 and spurred South African Airways to make an initial order for two aircraft fitted with US-built Pratt & Whitney engines. Just as the aircraft was being readied for its first commercial flights, World War II began. With the outbreak of hostilities, all models were requisitioned by the Luftwaffe for military air-transport roles, and later, long-range maritime patrol. Military aircraft production was begun by the company in the 1930s and eventually monopolized all its resources. Perhaps the most notable design was the Junkers Ju 87 "Stuka"
Junkers Ju 352 when, during the summer of 1944, the worsening war situation resulted in the decision to abandon further production of transport aircraft. In September the last two Ju 352As rolled off the assembly line, 10 pre-production Ju 352s and 33 production Ju 352s having been manufactured. Several developments of the basic design were proposed before production was halted, these including the Ju 352B with more powerful engines and increased defensive armament. Junkers Ju 352 The Junkers Ju 352 "Herkules" ("Hercules" in German) was a German World War II transport aircraft that was developed from the Junkers Ju 252. During the late