Yes, yes... That's all fine and good
95mustanggt, but a real engineer would note that aircraft measure their velocity in nautical miles per hour "knots", not kilometers per hour, meters per second, or standard miles per hour.
In this case, the speed of sound would be 644.306692541 knots give or take a few millionths, or 644.31 when significant digits are used for the conversion from m/s.
Smartass.
