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Question for the Garmin Expert Guys

N40ES

Well Known Member
When installing a GTX345 and the Altitude encoder (Garmin GAE 12) that fastens to the rear of the GTX345. If the area behind the panel my RV9A is not drafty or pressurized is it necessary to connect the GAE 12 to the Static lines? Or could you just leave it's orifice open and/or filtered? "Memory from the old Steam Gauge Simpler days says: "If Static system is clogged just break the Glass on the VSI and you will have Static pressure and Altimeter again". Maybe showing my age, but Is there a real difference? Ed S.
 
The answer is, maybe. If you have forward facing air vents open, the cabin may pressurize slightly. If closed, the high speed airflow over the top of the cabin (and thru leaky door seals) may cause the cabin to be a bit lower pressure. Although rarely large, it could be enough to toggle your pressure altitude by 100 feet. I’d hook the line up to a good static port.
 
You may have a problem with the transponder certification. It seems that the test for the ADSB compliance and the test set requires the equipment be connected to both the pitot and the static ports. If the GAE 12 is not connected, then the test will fail. Best to check with the shop that will be doing the transponder cert.
 
You should connect the encoder to the static system.
The aim is to get your altimeter and encoder to read the same.
"Cockpit static" can be significantly different from "real static", draughts are not the issue but the way the cockpit vents and external airflow changes the internal cockpit pressure.
 
Great explanations

All great replies, Thanks guys! It will be connected as designed.
 
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