What if - GPS fails??

[Carl_Froehlich]

Running dual HDX displays, GPS-250 and GTN-650 (via the SkyVIew ARINC). ADS-b out is provided by the GTN-650 Serial #2 feeding the SkyView XPDR. All work fine.

The issue:
- If the GTN-650 GPS goes south, the SkyView (with GPS-250 feeding Serial #5)) provides the navigation backup.
- If the GPS-250 goes south, I still have the GTN-650 feeding the SkyView PDF, but I assume without the GPS-250 I lose the SkyView moving map, and with it goes ADS-b displayed informationand such.

My questions:
- Is my assumption on what happens if the GPS-250 goes south correct?
- I have one open serial port (#4) on the GTN-650. I have one open serial port (#4) on the SkyView. Is there any problem using the GTN-650 serial output to feed the SkyView for GPS data as a backup mode? If not, what configuration should I use for the SkyView and GTN-650 serials? I assume I would only use the GTN-650 serial output to the SkyView serial input as I do not believe there is a SkyView serial output function for the GTN-650.

Carl

 

[swatson999]

Why don't you get an ARINC module and let the 650 drive *both* displays? I have a GNS430W + ARINC, and do everything for flight planning on that unit, with the SV nav info (moving map, HSI, etc.) being sourced from that. The GPS2020 (not 250) that I have is a) feeding the XPDR for ADS-B out, and b) a backup should the 430W fail.

N.B. If you do this, make sure that one and only source is used for both displays...it's VERY easy to get situationally confused if the SV GPS is driving the SV map/HSI, and the Garmin is driving its own, and the two are showing different flight plans or approaches or whatever.

 

[Carl_Froehlich]

Why don't you get an ARINC module and let the 650 drive *both* displays? I have a GNS430W + ARINC, and do everything for flight planning on that unit, with the SV nav info (moving map, HSI, etc.) being sourced from that. The GPS2020 (not 250) that I have is a) feeding the XPDR for ADS-B out, and b) a backup should the 430W fail.

N.B. If you do this, make sure that one and only source is used for both displays...it's VERY easy to get situationally confused if the SV GPS is driving the SV map/HSI, and the Garmin is driving its own, and the two are showing different flight plans or approaches or whatever.

Already do that. Not the issue at hand. I want a GPS feed from the GTN-650 to feed the SkyView in the event of the GPS-250 failing. The GTN-650, via the ARINC does feed the SkyVIew PDF, but my understanding is it does not feed the SkyView moving map.

Carl

 

[swatson999]

So you already have an ARINC box, with the GTN connected to it, but *not* to pin 3?

Whatever is on the ARINC most assuredly *can* feed the SV moving map, but I believe you must have pin 3 connected per the Installation Manual.

I don't know if you can just run any GPS output directly to one of the serial inputs on the SV itself, but hey...if you can', it's likely to be described in the Installation Manual.

 

[Carl_Froehlich]

Pin 3 is connected. But, my assumption is with the normal configuration this has the GTN feed the PDF, but not provide GPS position information to the SkyView moving map. That still comes from the GPS-250 (or GPS-20200.

Let me know if my assumption is wrong.
Carl

 

[swatson999]

That's because you have it set up that way in the menus. If the GTN is connected to the ARINC per the manual, and the settings are correct, then you can use that as the source for your map. See the section on GPS Source in the Navigation Mapping Software portion of the User's Manual.

You should also see the option in the FP menu. Be forewarned, you can have one source driving the HSI and the other driving your moving map via the FP (there's an option to ensure they're always both using the same source, though).

 

[airguy]

You should also see the option in the FP menu. Be forewarned, you can have one source driving the HSI and the other driving your moving map via the FP (there's an option to ensure they're always both using the same source, though).

And you definitely want to use that option to make sure they are the same source, or things get very confusing.

 

[swatson999]

And you definitely want to use that option to make sure they are the same source, or things get very confusing.

Indeed. Ask me how I know this.

 

[Marc_J._Zeitlin]

...has the GTN feed the PDF...

Alright - I know this is MY problem, but the continual referral to "PDF" files is driving me nuts. The EFIS is a PFD (Primary Flight Display), NOT a PDF (Portable Document Format).

 

[Carl_Froehlich]

Good discussion, however my orginal issue remains unresolved.

Under the following conditions (my normal configuration):
- GTN-650 providing the flight plan to the SkyView via the Dynon ARINC. The ARINC install per the SkyView install manual.
- The SkyView receiving GPS information from the GPS-250.

My assumptions are, if the GPS-250 dies then:
- The SkyView continues to receive flight plan deviation information, displayed on the PFD.
- The autopilot servos continue to work.
- The SkyView moving map no longer has position information as this comes from the GPS-250, so it becomes useless.

In other words, the GTN-650 does not provide GPS information for the moving map in the event of the GPS-250 failing.

My question - is this a correct assessment of what will happen?

Carl

 

[swatson999]

It would be a pretty dumb system that, having multiple sources of data, fails completely when only one of those sources fails. Now, assuming that you have the ARINC box properly connected, along with the serial line *to* the ARINC box as noted in the Installation Manual*, the answer to your question is NO, that is not what will happen.

From the User's Guide, Section 7 (same section I told you to read in post #6):

SkyView’s Moving Map display depends on the system having a valid GPS source. In the event of the failure of the primary GPS source used to display the Moving Map, SkyView will automatically use other available GPS sources that are configured in the system. SkyView determines which GPS source to use by using the following prioritized list of GPS sources:

POS 1-> GPS 1->GPS 2->GPS 3->GPS 4->POS 2->POS 3->POS 4

See the SkyView Classic / SE / HDX System Installation Guide for more information on setting up GPS sources.

You *have* read both the Installation Manual and the User's Manual, correct?

*From the Installation manual, section 12:

The SV-ARINC-429 also has a serial input that is designed to provide auxiliary information that ARINC-429 GPS outputs do not provide (such as altitude). SkyView needs this data to consider the input a valid and complete GPS position source. This input is not a general purpose serial port, and cannot be configured for other uses. Input coming into this serial port is assumed to be in Aviation format, which most ARINC-429 capable panel mount GPS units can output.
See the Third-Party Device Connection and Configuration Reference Guide document for information about connecting and configuring third-party ARINC-429 devices.

 

[swatson999]

For example, if your system has one SV-GPS-2020 configured as POS 1 and a Garmin device configured as GPS 1, the Moving Map will always use the SV-GPS-2020 as its primary data source. If the SV-GPS-2020 fails or you configure its input function to NONE, the Moving Map Page will use the Garmin device (or other GPS source) configured as GPS 1 as its primary data source.

Section 4, Skyview Installation manual.

I say again...have you *read the manuals*?

 

[swatson999]

You're welcome.