I regularly fly formation with another like airplane RV-3 and RV-8, mine has a Skyview, the other has a D-10. Both have the latest upgrades although the problem has persisted since we first noticed it. Both have been swung per Dynon compass swing procedures.
The problem is with both planes in tight formation compass heading will be plus or minus one or two degrees. GPS track will be exactly the same and true airspeed will be within one or two kts, but wind vector will vary widely. Usually the heading will be within 10-20 degrees and the variance can be either way. However velocity can be greatly different, with the D-10 usually reading lower.
I have not been able to correlate the magnitude of error to anything, such as crosswinds. As an aside, I have noticed the inertia ball on the Skyview seems to wander off screen at about 40kts crosswind.
So, I guess my question is do these two units differ in how they derive wind vector values? One would think that with compass heading, GPS track and true airspeed very close the two units would be equal.
The problem is with both planes in tight formation compass heading will be plus or minus one or two degrees. GPS track will be exactly the same and true airspeed will be within one or two kts, but wind vector will vary widely. Usually the heading will be within 10-20 degrees and the variance can be either way. However velocity can be greatly different, with the D-10 usually reading lower.
I have not been able to correlate the magnitude of error to anything, such as crosswinds. As an aside, I have noticed the inertia ball on the Skyview seems to wander off screen at about 40kts crosswind.
So, I guess my question is do these two units differ in how they derive wind vector values? One would think that with compass heading, GPS track and true airspeed very close the two units would be equal.