Well, airplanes do NOT fly according to IAS (this is just an "indication", uncorrected for temp and alt). All of our V's in the equations we use for lift, drag, pitching moment, dimensional derivatives.......assume TRUE AIRSPEED. I don't really want to debate this, as it is like trying to debate F=ma. I was just curious to see if anyone had application ideas for a true airspeed sensor in the hobby world. In the UAV world, it obviously has relevance in very low speed aircraft such as VTOLS, helicopters (which also have problems sensing because of all the downwash screwing up static ports), low speed MAVs (micros) and blimps and high altitude blimps (which are notorious for not being able to sense their airspeed).

This is not true. For example, a good rule of thumb is to increase the IAS by 2% for every 1000ft of altitude. If a certain airplane stalls @35 kts @ sea level, 2% of 35=0.7. so at 10,000 ft, this airplane will stall at an IAS of 42 kts, and at 20,000ft, it will stall at an IAS of 49 kts. 49 is not approximately 35.

Yes, this is a problem with low cost Pitot tubes, but most modern probes have a particular shape on the front end that actually make them insensitive to AOA or Beta up to 15 or 20 degrees. The measurement of static pressure is at the root of the airdata measurement problem. Both altitude and airspeed measurements are impaired by the limited accuracy of pressure sensors as the altitude increases and the airspeed decreases. Precise small, light, low cost absolute pressure transducers having a range from zero to sea level pressures for altitude measurements and very low differential pressures for airspeed measurements do not exist. Using .001 “Hg. as a practical threshold for accuracy and resolution of airborne pressure measurements, degraded accuracy of speeds occur below 25 kts and above altitudes of 60,000 feet. More precise measurement of pressure is very difficult and expensive. This defines the lowest speed and highest altitude where good airdata measurements can be made.

what's GS