Support for ARINC 429 VPATH?

Mark_Dickens

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The GTN-650 now supports enroute VNAV guidance, but Skyview is not seeing this through the ARINC box. Are there plans to enable this to get a vertical slope indicator and autopilot coupling? Very useful for crossing restrictions when using their along track offset feature.
 

rleffler

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The GTN-650 now supports enroute VNAV guidance, but Skyview is not seeing this through the ARINC box. Are there plans to enable this to get a vertical slope indicator and autopilot coupling? Very useful for crossing restrictions when using their along track offset feature.

I asked the same question on the AFS forum. Crickets......
 

Raymo

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You have to wonder if Garmin will share the necessary information to allow other vendors to add the capability in their software.
 

Mark_Dickens

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Considering that the GTN-650 is widely used with other instruments through the ARINC stream, I can't imagine that Garmin would pick this particular feature to go proprietary. Why isn't Dynon addressing this question?
 

Dynon

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Considering that the GTN-650 is widely used with other instruments through the ARINC stream, I can't imagine that Garmin would pick this particular feature to go proprietary.  Why isn't Dynon addressing this question?

Come on now - you asked your question yesterday. We didn't address the question instantly because we didn't have an instant answer.

There are lots of examples already where data isn't outputted, and not just by the 650, for proprietary reasons, the data just not being there, etc. So, we can certainly imagine that this feature is proprietary.

But first, can you be more specific about the feature you're speaking to? There are a couple of vnav-oriented planning/guidance features in the 650. What's the scenario that you're expecting guidance but aren't seeing it (please be specific)? I know there is a VFR oriented Visual Approach Guidance mode that was added last year, and we believe that that already works (IE gives vertical guidance alongside the HSI). There's a newer "GTN 650/750 descent vertical navigation" mode that adds top of descent and bottom of decent values, possibly with some additional guidance (per their marketing materials), for different phases of IFR flight. We don't know whether that data is published over ARINC in a way that's readable by non-Garmin devices, but we're looking into it.
 

Mark_Dickens

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;D No offense intended ;D The other poster had asked the question and gotten "crickets" so I was just wondering.

What I'm talking about is the new feature in v6.50 of the GTN software. Here's the response I got from Garmin over on VAF:

"VNAV (VPATH) guidance is different from glidepath/glideslope approach guidance, and thus anyone providing support for VNAV A429 data would need to add this support separately.

Garmin has already added this support and released new V5.50 software for G5 systems (with/without autopilot), and is currently testing the new V6.20 software with this capability for G3X Touch systems."

I have no idea what's involved here and assumed there was a standard for VPATH...I gather that assumption is incorrect. If Skyview could support coupling the autopilot to the VNAV info, that would be really nice.
 

rleffler

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;D No offense intended ;D The other poster had asked the question and gotten "crickets" so I was just wondering.

What I'm talking about is the new feature in v6.50 of the GTN software. Here's the response I got from Garmin over on VAF:

"VNAV (VPATH) guidance is different from glidepath/glideslope approach guidance, and thus anyone providing support for VNAV A429 data would need to add this support separately.

Garmin has already added this support and released new V5.50 software for G5 systems (with/without autopilot), and is currently testing the new V6.20 software with this capability for G3X Touch systems."

I have no idea what's involved here and assumed there was a standard for VPATH...I gather that assumption is incorrect. If Skyview could support coupling the autopilot to the VNAV info, that would be really nice.


In all fairness to Dynon, AFS, et al, no EFIS vendor that I'm aware supported vertical data when in the enroute mode of the GPS. It is only supported in the approach mode when the approach is activated and the vertical mode has been armed. Even Garmin's EFIS don't support these features at release time and they were the developers. It's no surprise that they are going to be the first on board.

There are two new features that Garmin released this past week. The first is to set an altitude for each fix in the flight plan. This enables you set different altitudes for different segments of you flight. If I understand this mode properly, you start your descent or ascent once you reach the fix.

The other is a slight variation of the above in that you can set a point in which you want to be at a specific altitude. This will enable started an ascent or descent so that you are at the desired altitude when you reach that point.

This is going to require new code from all the vendors. The question is if it's in their development cycle and when it's anticipated to be released. I doubt that it will be a quick release for any of the vendors other than Garmin. But I'm willing to be pleasantly surprised.

To clarify my "crickets" comment, when I asked on the AFS forum, I was expecting some sort of response ranging from "what new feature of the 650" to "not in the current development schedule" or "give us x months, we're working on it". No response was given.

From the comments given here by Support, I'm interpreting that it's still in the discovery phase for Dynon (and probably all other vendors too) and there isn't a plan yet until they can get the code and see what is on the ARINC bus. I suspect that vendors probably got the code the same day we did.
 

swatson999

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I can imagine quite a few use cases to work out before any such feature would be released. E.g., you have various crossing altitudes set, or flight segment altitudes set, then either request or get assigned something different. How do you easily and safely enter a new altitude for your current leg? Does that override the ones for the next set of legs? And so on...

Lots of combinations and scenarios to work out.
 
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