We can measure our TAS at some Altitude, say 3000' and temperature say 63F, by flying in three different directions (say 0, 120, 240 degrees) and averaging the GPS reading. This would be our True Airspeed at 3000' and 63 F right?
So how can we calculate our speed at sea level and 59F (standard definition)? I Googled it and came up empty.
I've been using an old Cessna performance chart and eyeballing it.
There must be a way to calculate it... Any math guys out there!
