Messerschmitt Bf 109 11 July 1938 when Erhard Milch finally allowed Willy Messerschmitt to acquire the company. All Messerschmitt aircraft that originated after that date, such as the Me 210, were to carry the "Me" designation. Despite regulations by the RLM, wartime documents from Messerschmitt AG, RLM and "Luftwaffe" loss and strength reports continued to use both designations, sometimes even on the same page. All extant airframes bear the official "Bf 109" designation on their identification plates, including the final K-4 models. The aircraft was often referred to by the folk-designation, 'Me 109', particularly by the Allies. The aircraft was often nicknamed "Messer"
Messerschmitt Bf 109 operational history first saw active service in the Condor Legion against Soviet-supplied aircraft in mid 1937 as a testing ground for the new German fixed-wing fighter plane. The Bf 109 quickly replaced the Heinkel He 51 biplane fighter which suffered many losses during the first 12 months of the conflict. Of the Luftwaffe's "Jagdgruppen", 136 Bf 109s were sent to Spain, and 47 of these, including Bf 109Bs, Ds and Es remained behind in service with the Spanish Air Force after the conclusion of the war in 1939. The Republican fighters were no match for the Bf 109, equipped mostly with Soviet