I have had my Sport HS EFIS providing altitude information to my GNS430 and GTX327 using the Fuel/Air Data Z Format for many years.
I have now replaced the GTX327 with an Appareo ESG transponder. It does not accept the Fuel/Air Data Z Format. I found that if I use the Trimble/Garmin encoding altimeter output of my EFIS, the ESG will function correctly. However that required that I change the altitude input format on my GNS430 to Icarus-alt. (the wiring from the EFIS splits to the GNS430 and the transponder).
I think the GTX327 needed air data to obtain GPS information primarily to know when the aircraft is in motion to switch from STBY to ALT mode. Since the ESG has a built in GPS, all it needs is altitude data. I think the same can be said of the GNS430, it only needs altitude data and not GPS or pitot airspeed data.
I think this is OK but would like confirmation.
Thanks
Jim Butcher
Altitude Encoding
Re: Altitude Encoding
The GNS430 can use the airspeed, wind, and fuel information in the Fuel/Air Data message, mainly for flight planning and display. The airspeed information is also provided in the ARINC-429 connection.
Note you can use the "Serial--trim/gar-25 ft" (higher resolution) setting in the Stratus.
Note you can use the "Serial--trim/gar-25 ft" (higher resolution) setting in the Stratus.
Re: Altitude Encoding
Small note: As of a few years ago the FAA recommended procedure is to turn auto-switching off; run the transponder in ALT mode whenever the engine is on.
Re: Altitude Encoding
Thanks Jeff and Bob. It looks like I will be fine as I have it configured.
This information would be useful in the GRT Equipment Supplements document. I had no idea that my GRT would have the accuracy to use the higher resolution setting in the ESG.
Jim Butcher
This information would be useful in the GRT Equipment Supplements document. I had no idea that my GRT would have the accuracy to use the higher resolution setting in the ESG.
Jim Butcher