Oh yeah, Me 262 could brake sound barrier.
"The HG series of Me 262 derivatives was estimated to be capable of reaching transonic Mach numbers in level flight, with the top speed of the HG III being projected as Mach 0.96 at 6 km altitude. Despite the necessity to gain experience in high-speed flight for the HG II and III designs, Messerschmitt undertook no attempts to exceed the Mach 0.86 limit for the Me 262."
"After Willy Messerschmitt's death, the former Me 262 pilot Hans Guido Mutke claimed to be the first person to break the sound barrier on 9 April 1945 in a Me 262, in a "straight-down" 90° dive. This claim is disputed because it is only based on Mutke's memory of the incident, which recalls effects that other Me 262 pilots have observed below the speed of sound and a high airspeed indicator reading, but no altitude reading, which would be required to determine the actual speed. Furthermore, the pitot tube used to measure airspeed in aircraft can give falsely elevated readings as the pressure builds up inside the tube at high speeds. Finally, the Me 262 wing had only a slight sweep incorporated for trim (center of gravity) reasons and likely would have suffered structural failure due to divergence at high trans-sonic speeds."
http://en.wikipedia.org/wiki/Me_262That German guy is either a liar, some crazy bufoon or actually did it.