Junkers Ju 87 with the Ju 87 A-0, the B-1s were returned discreetly to the Reich. The experience of the Spanish Civil War proved invaluable - air and ground crews perfected their skills, and equipment was evaluated under combat conditions. The Ju 87 had not been tested against numerous and well-coordinated fighter opposition; this lesson was learned later at great cost to the Stuka crews. All Stuka units were moved to Germany's eastern border in preparation for the invasion of Poland. On the morning of 15 August 1939, during a mass-formation dive-bombing demonstration for high-ranking commanders of the Luftwaffe at Neuhammer training grounds
Junkers J 1 end of January 1916, Junkers had been given a contract to further develop his all-metal concept, and the later Junkers J 2 single-seat fighter, which would never see frontline service, was the follow-on to the J 1. The J 2 would only bear a superficial similarity to the J 1, being more aerodynamically refined and slightly smaller in scale, yet nonetheless the two aircraft shared an essentially similar structure. It is believed that the Junkers J 1 was not flown again after January 1916. However, it survived the First World War, and was placed on static display in 1926 at