Originally posted by Widewing
The second man through the sound barrier.
Actually, he's no more than the fifth or sixth man through the sound barrier, considering the annotations in the Me 262 A-1 Pilot's Handbook (ref: F-SU-111-ND dated 10 January 1946, issued by Headquarters AIR Material Command, Wright Field, Dayton, Ohio, classification cancelled 3 June 1955), from the British test pilots evaluating the plane:
Speeds of 950 km/hr (590 mph) are reported to have been attained in a shallow dive 20° to 30° from the horizontal. No vertical dives were made. At speeds of 950 to 1000 km/hr (590 to 620 mph) the air flow around the aircraft reaches the speed of sound, and it is reported that the control surfaces no longer affect the direction of flight. The results vary with different airplaces; some wing over and dive while others dive gradually. It is also reported that once the speed of sound is exceeded, this condition disappears and normal control is restored.
The conditions experienced by Hans Guido Mutke during his flight on 9 Apriil, 1945 match the description given by the British test pilots. Additionally, both Welch (in the XP-86) and Goodlin (in the X-1) exceeded Mach 1 in dives prior to Yeager's flight.
Yeager's distinction is that he is the first man to have exceeded Mach 1
in level flight[/u].