[bongodriver]

Here we go, graphs and equations and name dropping German scientists.....all this fuss for what is simply compressibility error.

interestingly enough compressibility error makes an ASI 'over read' so not sure why compressibility error will have been a factor in the Russians tests not being able to reach speeds.

to this day the simple rule of thumb of 2% indicated airspeed per 1000' of altitude added gives a pretty accurate TAS result.