Messerschmitt Bf 109 was called the Me 109R, suggesting it was just another variant of the standard fighter, but in fact it was a racing aircraft having little in common with the Bf 109. It was powered by the DB 601ARJ, producing 1,156 kW (1,550 hp), but capable of reaching 1,715 kW (2,300 hp). This world record for a piston-engined aircraft was to stand until 1969, when Darryl Greenamyer's modified Grumman F8F Bearcat, "Conquest I", broke it with a 777 km/h (483 mph) record speed. When the Bf 109 was designed in 1934, by a team led by Willy Messerschmitt and Robert Lusser,
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