Altimeter Correction

[Randy]

I just had the Pitot/Static and XPNDR test done by a qualified technician. He dialed the test to 10,500' and my Dynon altimeter showed 10,460'. Is there a way that I can dial in a 40 foot correction in the Dynon HDX system ? If so, how ?

 

[Kevin D]

Not with the documentation at the moment and hate to be the one to say it is in the manual without reference but the procedure is in there.
A more relevant question is what were the values and errors at other points from sea level to 10,500?

 

[Randy]

It is 40' off consistently throughout the climb, e.g. when 5000' true (and tranmitted via xpndr) my HDX show 4960'. It is not off by a %. At field elevation, I am 40' off.

 

[GalinHdz]

What do you mean by "5000 true"? The transponder sends out pressure altitude (not compensated for barometric pressure) to ATC. The ATC RADAR display adjusts for the current barometric pressure in the area you are flying. Make sure you are NOT using GPS altitude as "true" altitude. It will rarely be the same as XPONDER reported altitude.

Did it pass the XPNDR test done by the technician?

 

[RV8JD]

... At field elevation, I am 40' off.

This may not address your issue, but on page 5-19 of the SkyView System Installation Guide:

"ALTITUDE OFFSET
There is a single point altitude adjustment, located in SETUP MENU > HARDWARE CALIBRATION > ADAHRS CALIBRATION > ALTITUDE OFFSET that adjusts SkyView’s barometric altimeter. This adjustment affects both the displayed altitude and the encoded altitude that is sent to other devices. It should only be adjusted if altitude is found to be incorrect (by comparing it against a known source or field elevation, after the BARO setting has been set to correctly to known atmospheric conditions) after SkyView has fully warmed up."

 

[swatson999]

I just had the Pitot/Static and XPNDR test done by a qualified technician. He dialed the test to 10,500' and my Dynon altimeter showed 10,460'. Is there a way that I can dial in a 40 foot correction in the Dynon HDX system ? If so, how ?

A qualified tech should have known this, as well as all the other info from Dynon on how to conduct a static/xpdr test, including adjusting the offset for the altimeter (it's in the manual; see above post). Mine did.

 

[Randy]

RV8JD, your response was spot on and very much appreciated ! That was exactly the input I was hoping for. I will now "make it so".