The Me 163A V4 was shipped to Peenemünde to receive the HWK RII-203 engine in May 1941. By 2 October 1941, the Me 163A V4, bearing the radio call sign letters, or Stammkennzeichen, “KE+SW”, set a new world speed record of 1,004.5 km/h (624.2 mph), piloted by Heini Dittmar, with no apparent damage to the aircraft during the attempt.
