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IFR Upgrade

Scaevola

I'm New Here
Planning IFR upgrade. Currently have GRT HX EFIS with GRT 4 axis A/P Servos with Electric Trim off the stick. My old Bendix King VFR GPS and non ADS-B Xponder need to go. Looking at an all Avidyne Nav/Com panel (IFD 440 and ADS-B Xponder) with Avidyne audiopanel. Garmin heated pitot is also needed. Will have GRT upgrade the AHRS with dual magnetometer and plan to make a new panel, with a new HXr on the left and the current HX on the right?each cross referencing each other. Does anyone have any advice on the GRT-Avidyne avionics combination? Cost of hardware for the upgrade is so far US$22,000.
 
WAAS

The uAvionix ADSB will provide WAAS GPS signal to the HXr. Use the Fly Safe GPS from GRT and it also adds a data combiner to give you 4 more data ports.
 
Given our dependence on GPS, I would highly recommend getting the multi-constellation satellite receiver built into the GRT Adaptive AHARS. This will allow you to continue (VFR) navigation in the event of a GPS signal degradation, using other navigation satellite constellations.

Not sure why you feel the Garmin heated pitot is required - there are others out there, including the Dynon with built-in AOA sensing. If getting the new pitot to obtain both heat and AOA I would suggest you span your search out a bit. Also, if you want AOA, adding this option (Sensed AoA) to the GRT Adaptive AHARS is a bargain. I have this feature and enjoy the added awareness it provides, particularly in slower flight regimes.

With respect to the FlySafe GPS as a position source for ADSB, if you are already adding a certified GPS navigator then the FlySafe would be overkill. If you still need more RS232 communications ports, GRT sells a 1:4 port combiner without the GPS option.
 
The uAvionix ADSB will provide WAAS GPS signal to the HXr. Use the Fly Safe GPS from GRT and it also adds a data combiner to give you 4 more data ports.

Since he’s in Australia a UAT won’t work for him.

Have you thought about a small backup battery for one EFIS?
 
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Thankyou. Installing the Avidyne IFD 440, which integrates better then Garmin with my AVPLAN (provides another Attitiude Reference) and anecdotally involves fewer steps for flightplanning and most inputs than the Garmin equivalent. GRT are currently upgrading the AHRS to the GADAHRS with AOA, so should I ask them about including the multi-constellation satellite receiver? My first time hearing about this, so will look it up.
Thanks.
Joel
 
I would like to have a backup battery for the HXr but GRT only provide one with their Mini EFIS. Can i make my own backup without voiding warranty?
 
I would like to have a backup battery for the HXr but GRT only provide one with their Mini EFIS. Can i make my own backup without voiding warranty?

GRT specifically recommends a backup battery made by TCW (<tcwtech.com>) for the HXr. But many people have made their own. Just make sure it is isolated from a failure of the main system. The multiple power inputs on the HXr are already diode-isolated.
 
To your earlier question... Yes, get the GNSS sensor installed in the new AHARS package so your EFIS will be capable of fully stand-alone flight planning in the event of failure of your IFD440.

As for a backup battery, it may be wise to consider installing an Essential bus or similar, powering the second power input of your EFIS and AHARS as well as, perhaps, your IFD. The Essential Bus will take its power from a circuit breaker on the main bus, through a diode, to the Essential Bus and it's associated circuit breakers. A small, independent battery can be tied to the Essential Bus through a robust switch or via a small solenoid. In this manner the Essential Bus is normally powered by the Main Bus, with the Essential battery available to provide backup power in the event of a failure of the main bus.

In operation, one switches on the Essential Bus Battery and powers up the EFIS and GPS equipment prior to engine start - this allows all these boxes to get aligned, get positions, and perhaps get a flight plan added. The Essential Bus Battery then protects the equipment from "brown out" during engine start and gives you full engine instrumentation right through the engine start cycle.

In the event of a failure of the Main Bus (alternator failed and main battery discharged, main battery failed, master contactor failed, etc) the Essential Bus Battery will continue to power your essential equipment until it becomes depleted.

The above power distribution design is fully supported by the GRT equipment, thanks to their units having three individual power inputs. The IFD would be powered directly from the Essential Bus.

I have our aircraft wired in this fashion and it works a charm. Of course we also have a Mini-X installed and, with its internal battery option we will have reliable Primary Flight Display and VFR flight planning available for a long time. In fact with some manual shedding of high-current loads (pitot heat, landing lights, strobes), we can sustain an alternator failure shortly after takeoff and still have electrons flowing after burning off all of the 50 gallons of fuel on board.
 
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