On Tuesday, October 23, 2012 9:15:33 PM UTC-7, akiley wrote:
I think we may do more tests this fall. Was just at Williams Soaring Center renting there excellent ships, an ASW27 and 24. The air was very stable and I had high tows to 8000 over the mountains. I also now have a Colibrii II logger so I may have more accurate altitudes compared to GPS only. I may just look at segments in SeeYou and work out the performance using altitude lost over time. This takes wind out of the equasion. I will do the same for flights I have done in the Standard Cirrus if I have some resonable segments. But we had an amazing season in Michigan so most of that data will be totally polluted by volitile air.



Since I did a range of speeds with the older Cirrus tests, it seems I should have found reasonable performance at ONE of the speeds. BTW, Our Cirrus finish looks excellent to me.



... Aaron

How do you plan to take the wind out of the equation? If you take ground distance out of the equation, and use altitude loss, you need to know your true airspeed. SeeYou will claculate it for you, but depend on the igc file you have, it is usually deriving TAS and IAS from the ground speed and calculated wind, but unfortunately the calculated wind can be very inaccurate, so your TAS will be far from accurate. The only accurate information that SeeYou has is distance flown and altitude loss. Altitude loss may be pressure or GPS. Pressure Altitude is more accurate, although GPS altitude is the closest to true altitude. SeeYou calculates L/D based on distance flown and altitude loss.

Ramy