Originally Posted by
JD-EE
...Speaking of math - how does Mach .82 become something under 300 knots IAS...
Its the speed that would give same dynamic pressure at standard air density (sea level) - useful because its basically what the wings use to generate lift, independent of altitude Its also basically what pitot tubes measure - think simple analogue dial without all the digital compensations! See also the definition of Flight Level FL and its link to real altitude in ft.