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 in Finland. "MT-452" is on display at the airfield in Utti, and the Central Finland Aviation Museum displays "MT-507", which was the last flying Bf 109 of the FAF. The Finnish airplane constructor "Valtion Lentokonetehdas" also manufactured a fighter, called VL Pyörremyrsky, whose appearance greatly resembled the Bf 109 but which also features some significant improvements, such as significantly easier handling, different wing construction, and re-designed landing gear. One single aircraft was produced before the end of the war; it is today displayed at the Central Finland Aviation Museum. Further, the doctoral thesis by the Finnish aircraft expert Hannu Valtonen