dynon

[David Lloyd]

Be careful with the wording.  Yes the GNX375 will work with the Dynon as far as the navigation stuff.  The 375 has ADSB in and out.  Dynon won't display the in from the 375.  Must use the ADSB receiver from Dynon for about $1K.

[SpamPilot]

Thanks to those that have commented so far, I appreciate it.

I'm not disputing it will work, but it sure looks like it is not legal.

The STC clearly states that the GNX 375 must be installed IAW the installation manual.  The installation manual clearly states that any device connected to the GNX 375 not on the compatibility list requires "additional airworthiness approval".  The SkyView HDX is not on the compatibility list.  Therefore it's not legal to connect the GNX 375 to the HDX without additional airworthiness approval.  This means a Field Approval.  I am not an A&P (or lawyer), but you don't need an A&P to explain this to you.  The language is plain and clear.  FWIW, my avionics shop did confirm this explanation. 

I did talk to Dynon.  Their response was friendly, but it didn't clear anything up.  Although I asked, they made no claim that connecting an HDX to a GNX 375 was, in fact, legal.  I interpret that to mean they are aware of the issue, they (wisely) won't make any claims that it is legal, and they are (appropriately) leaving it up to the purchaser to figure out with the help of their A&P/IA (as anyone should).  They provided no guidance on how to obtain a Field Approval.  They did provide a wiring diagram, which is helpful, but anyone can draw up a wiring diagram.  It does not equate to airworthiness approval.

Moreover, the HDX Certified installation manual says:

"When connecting to third-party products, refer to the Dynon Avionics instructions as well
as the product manufacturer instructions to ensure the products are configured and wired
for compatibility with the SkyView HDX System."

When you follow these instructions (which is required by the HDX STC), and you consult the GNX 375 IM, you find that the GNX 375 IM contains no instructions that would enable you to configure and wire the GNX 375 to an HDX.  Instead, you find that the GNX 375 IM has a compatibility list and is resticted to connecting only to devices on that list, and the HDX is not on it, whereas some other EFISes are.  There is no "generic" ARINC 429 installation.  The IM does allow connecting to devices not on the compatibility list subject to "additional airworthiness approval", but gives no guidance on how to obtain that approval (and neither does the Dynon IM).

It may be that a Field Approval is easy to get for this, in which case it should be straightforward for the GA community to share the data that the FAA accepted, or better yet for Dynon to provide such data since they have a financial interest.

With respect and without prejudice, I would say it may also be that a Field Approval is hard to get, or at least an unknown, and hopeful owners are using shops who have overlooked or not researched the plain language of the STC.  It did take me a non-trivial amount of time to piece this together.  An A&P/IA signing off does not make the installation legal if it was not installed IAW both installation manuals.  Since the owner is responsible for airworthiness, accountability in that case points back to the owner.

Again, it's totally fine to have both installed, you just can't connect them without obtaining a Field Approval.  And I'm not complaining about the fact that the HDX isn't on the GNX 375 compatibility list.  Dynon is under no obligation to talk to Garmin and vice versa, it was my choice to buy the GNX 375, and if SkyView compatibility were something I wanted badly, I had the opportunity to discover this issue before making my purchase decision.  I would *like* to have an HDX in my panel.  I would even consider installing the system without connecting it to the GNX 375 until such time as Dynon and Garmin talk and Garmin updates its compatibility list, or a straightforward process for Field Approval becomes documented.  (I'm also willing to consider just going with a G3X, because it's compatible and I don't have to deal with any uncertainty.)  My hope was that someone else in the community might say "oh, I've been through this, it was easy to get a Field Approval because the FAA recognized that it's just an ARINC 429 interface between the two" or "Garmin provided me with a letter confirming compatibility and the FAA was good with that" or "hang on, here's chapter and verse from the regs that explain why it is actually legal" or whatever.

[midlifeflyer]

8 hours ago, TNIndy said:

I was considering the GNX 375 to pair with the Dynon system I just purchased. Dynon says that it will work. It was a nightmare deciding which GPS unit to go with but I finally decided on the IFD540 after initially promising myself that I wouldn't spend that much. I suggest calling Dynon. They have great customer service and answered questions for about 2 years before I bought anything. We are wiring mine for a future autopilot and a second screen. It looks like the second screen may have to be the 7". If anyone has two Skyview screens in a 201/231 style panel id like to see pics

A potential student is in the process of buying an LSA with an HDX. Might end up on leaseback. Dynon doesn't have saved per user settings like some other systems so I  asked a question about setting up a file to load my student's configuration on a stick so we can load it when he flies in case others make changes. I asked about it in a message on their Facebook page*. As most know, company Facebook pages are often  handled by someone who doesn't necessarily know much and just passes you on. Not Dynon. He walked me through the possibilities and even sent me a file I could study and play with editing. That's exceptional.

(* Their user forum has (had?) a current problem registering new members.)

[Yetti]

On 11/5/2021 at 3:18 PM, SpamPilot said:

Thanks to those that have commented so far, I appreciate it.

I'm not disputing it will work, but it sure looks like it is not legal.

The STC clearly states that the GNX 375 must be installed IAW the installation manual.  The installation manual clearly states that any device connected to the GNX 375 not on the compatibility list requires "additional airworthiness approval".  The SkyView HDX is not on the compatibility list.  Therefore it's not legal to connect the GNX 375 to the HDX without additional airworthiness approval.  This means a Field Approval.  I am not an A&P (or lawyer), but you don't need an A&P to explain this to you.  The language is plain and clear.  FWIW, my avionics shop did confirm this explanation. 

I did talk to Dynon.  Their response was friendly, but it didn't clear anything up.  Although I asked, they made no claim that connecting an HDX to a GNX 375 was, in fact, legal.  I interpret that to mean they are aware of the issue, they (wisely) won't make any claims that it is legal, and they are (appropriately) leaving it up to the purchaser to figure out with the help of their A&P/IA (as anyone should).  They provided no guidance on how to obtain a Field Approval.  They did provide a wiring diagram, which is helpful, but anyone can draw up a wiring diagram.  It does not equate to airworthiness approval.

Moreover, the HDX Certified installation manual says:

"When connecting to third-party products, refer to the Dynon Avionics instructions as well
as the product manufacturer instructions to ensure the products are configured and wired
for compatibility with the SkyView HDX System."

When you follow these instructions (which is required by the HDX STC), and you consult the GNX 375 IM, you find that the GNX 375 IM contains no instructions that would enable you to configure and wire the GNX 375 to an HDX.  Instead, you find that the GNX 375 IM has a compatibility list and is resticted to connecting only to devices on that list, and the HDX is not on it, whereas some other EFISes are.  There is no "generic" ARINC 429 installation.  The IM does allow connecting to devices not on the compatibility list subject to "additional airworthiness approval", but gives no guidance on how to obtain that approval (and neither does the Dynon IM).

It may be that a Field Approval is easy to get for this, in which case it should be straightforward for the GA community to share the data that the FAA accepted, or better yet for Dynon to provide such data since they have a financial interest.

With respect and without prejudice, I would say it may also be that a Field Approval is hard to get, or at least an unknown, and hopeful owners are using shops who have overlooked or not researched the plain language of the STC.  It did take me a non-trivial amount of time to piece this together.  An A&P/IA signing off does not make the installation legal if it was not installed IAW both installation manuals.  Since the owner is responsible for airworthiness, accountability in that case points back to the owner.

Again, it's totally fine to have both installed, you just can't connect them without obtaining a Field Approval.  And I'm not complaining about the fact that the HDX isn't on the GNX 375 compatibility list.  Dynon is under no obligation to talk to Garmin and vice versa, it was my choice to buy the GNX 375, and if SkyView compatibility were something I wanted badly, I had the opportunity to discover this issue before making my purchase decision.  I would *like* to have an HDX in my panel.  I would even consider installing the system without connecting it to the GNX 375 until such time as Dynon and Garmin talk and Garmin updates its compatibility list, or a straightforward process for Field Approval becomes documented.  (I'm also willing to consider just going with a G3X, because it's compatible and I don't have to deal with any uncertainty.)  My hope was that someone else in the community might say "oh, I've been through this, it was easy to get a Field Approval because the FAA recognized that it's just an ARINC 429 interface between the two" or "Garmin provided me with a letter confirming compatibility and the FAA was good with that" or "hang on, here's chapter and verse from the regs that explain why it is actually legal" or whatever.

Dynon supplies the ARINC interface for connecting a certified IFR navigation source.   It looks like the 375 is a certified IFR source.   I would go along those lines.   You may find that the data format for the 375 is the same as a 430W.   I would also send a note to Dynon and see if there are plans to add it to the list.

[SpamPilot]

"Dynon supplies the ARINC interface for connecting a certified IFR navigation source.   It looks like the 375 is a certified IFR source.   I would go along those lines. "

Going along those lines puts one in direct conflict with the language of both the STC and the GNX 375 install manual, so one can't simply go along those lines (at least not without getting a Field Approval).  Even the Dynon installation manual says you have to comply with both the Dynon and the third party manuals.

[EricJ]

14 hours ago, SpamPilot said:

"Dynon supplies the ARINC interface for connecting a certified IFR navigation source.   It looks like the 375 is a certified IFR source.   I would go along those lines. "

Going along those lines puts one in direct conflict with the language of both the STC and the GNX 375 install manual, so one can't simply go along those lines (at least not without getting a Field Approval).  Even the Dynon installation manual says you have to comply with both the Dynon and the third party manuals.

You really need to change whatever it is that makes your posts show up in that font.   It's nearly unreadable on my display.

[NotarPilot]

Does anyone know what exactly is contained in the SkyView US Aviation/Obstacles Database? The website doesn't really say what's in it.