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
Bristol Aeroplane Company Bristol Record Office include the papers of Lionel Harris, an engineer at the Bristol Aeroplane Company in the 1940s (Ref. 42794) (online catalogue) The Bristol Engine Company was originally a separate entity, Cosmos Engineering, formed from the pre-First World War automobile company Brazil-Straker. In 1917, Cosmos was asked to investigate air-cooled radial engines and, under Roy Fedden, produced what became the Cosmos Mercury, a 14-cylinder two-row (helical) radial, which they launched in 1918. This engine saw little use but the simpler nine-cylinder version known as the Bristol Jupiter was clearly a winning design. With the post-war rapid contraction of military