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 J.I to the Canada Aviation and Space Museum in 1969. Additionally, one Junkers J.I fuselage exists, at the Museo Storico dell Aeronautica Militare Italiana in Vigna di Valle. This aircraft was previously exhibited at the Leonardo da Vinci Museum at Milano and was restored at the Technical Museum of Berlin between 2005 and 2010. A flyable Junkers J.I replica is under construction in Hungary. Junkers J.I The Junkers J.I (manufacturer's designation J 4) was a German "J-class" armored sesquiplane of World War I, developed for low-level ground attack, observation and Army cooperation. It is especially noteworthy as being the first all-metal