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 670 km/h (416 mph) at . The Initial Rate of climb was /min, without MW 50 and /min, using MW 50. The Bf 109 remained comparable to opposing fighters until the end of the war but the deteriorating quality of the thousands of novice "Luftwaffe" pilots pressed into service by this stage of the war meant the 109's strengths were of little value against the numerous and well-trained Allied fighter pilots. Several other versions were projected based on the 109K airframe – K-6, K-8, K-10 and K-14. In the proposed K-6 the armament would have been two 13 mm (.51