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 variants experienced fighter aces, like Werner Mölders, were the first ones to fly the Bf 109 F-1s in combat in October 1940. A total of 208 F-1s were built between August 1940 and February 1941 by Messerschmitt Regensburg and the "Wiener Neustädter Flugzeugwerke" (WNF). The F-2 introduced the 15 mm Mauser MG 151 cannon with 200 rounds. As the harder-hitting 20 mm Mauser MG 151/20 version become available, a number of F-2s were retrofitted with it in the field. About 1,230 F-2s were built between October 1940 and August 1941 by AGO, Arado, Erla, Messerschmitt Regensburg and WNF. No tropicalized version