GPS III Pilot calculates winds wrong

[grenwis]

My GPS III Pilot usually tells me that the winds are blowing 99 knots from some direction or another. I see this when I use the E6B function within the GPS. Now that I have a Dynon EFIS, I see the same kinds of big numbers reflected there. Has anyone seen this. I have been guessing that it has to be related to calibration of indicated heading. The GPS heading and speed must be right. My indicated airspeed agrees with other pilot's reading when I fly formation with them so I assume that is right. That leaves heading. But to get a huge wind speed like 99 knots, my heading would have to be way off, right?

Has anyone else seen this?

[RGaines]

I initially had the same problem with my AvMap and the Dynon. The problem was that the AvMap was sending data to the Dynon that did not include magnatic variation. So when the Dynon tried to compute the winds aloft it came up with huge numbers. AvMap came out with an updated program that was for the Trio autopilot but worked great on the Dynon.

I don't know if this is the same type of problem but mine was a software error from the gps.

Rich

[asav8tor]

http://www8.garmin.com/products/gpsI.../download.html