Quote Originally Posted by Airmutt View Post
There is an app available where you can plug in local wind speed and direction and it provides TAS. And to make Ron B happy one can even define the airspeed ranges on the display. Is it perfect, no.... but its a free and getting better!!
I love, love, love your effort! BUT ...

Even if one could input local wind speed and direction (from ASOS or AWOS which is measured or corrected to 10 meters ~33 feet), wind is not a constant and varies with time and altitude in both direction and magnitude. In addition, TAS is not directly relatable to airspeed limitations like Vne, Vfe, Vle, Vs, etc. TAS is temperature dependent. So, one would need to measure temperature (and correct it (temperature) for Mach number). With a lot of effort, you MIGHT get there with altitude, but you are still not there with airspeed. You need to know dynamic pressure (Ptotal - Pstatic) as flight characteristics and structure depends on it.

Regretfully, Ron W's point above about flying under class B airspace layers can be accomplished utilizing GPS altitude because those airspace layers are a tapeline (physical) altitudes (msl and/or agl) and not pressure-based altitudes.

Blue on Top,
Ron "you're making me think (and learn) a lot" Blum.