Need help understanding IFR Navigators

[R7237]

I might be showing my ignorance, but here goes:
What does an IFR navigator (like GPS-175) provide that a WAAS GPS (like SV-GPS-2020) does not,, other than TSO certification?
I am building the panel on an RV-12iS build as an EAB that I want IFR capability to use for Trainning purposes. I can add a nav radio (like Val NAV 2k) and take care of ILS/GS/VOR, but am trying to decide the need for a GPS-175 vs just using the SV-GPS-2020. Obviously price is the concern ($4250 vs $500). The airplane will have an autopilot.
Does the GPS-175 allow for RNAV approaches that the SV-GPS-2020 does not?
The airplane will have an AFS-5500 as the primary flight EFIS and the Dynon SV autopilot.

Thanks in advance.

[N546RV]

Your AFS display will not have the capability to load approaches, pure and simple, whereas the GPS-175 will. Keep in mind that the GPS-175 is a full-fledged GPS navigator unit, whereas the SV-GPS-2020 is simple a GPD receiver puck whose sole purpose is to provide position data to a compatible EFIS screen.

[N804RV]

The Garmin adds enroute and terminal IFR navigation and GPS based approaches. Whereas, the Dynon hockey puck only gives you an ADS-B out position source and VFR Navigation.

You could file and fly IFR with ILS/VOR. But, once you fly IFR GPS, you'll be hooked. Especially with some cool glass, like the Skyview system.

[dlloyd3]

Download the Garmin user guide and it describes all the self testing the 175 does in the background. It will give alerts and even cancel approaches if anything is amiss. Lot of stuff going on in that little box. If you want to do IFR training the 175 will also simulate an ILS approach with dire warnings of for training purposes only. The Dynon system needs a GPS reference and the 2020 works well with it. $500 well spent.

[R7237]

Originally Posted by dlloyd3

Download the Garmin user guide and it describes all the self testing the 175 does in the background. It will give alerts and even cancel approaches if anything is amiss. Lot of stuff going on in that little box. If you want to do IFR training the 175 will also simulate an ILS approach with dire warnings of for training purposes only. The Dynon system needs a GPS reference and the 2020 works well with it. $500 well spent.

Would you recommend I install both the SV-GPS-2020 and the GPS-175?
I figured with an ARINC adaptor, I would provide the GPS data from the GPS-175 to the AFS 5500 and the SV-GPS-2020 would don't be needed,,,, GPS data to the transponder as well.

[GalinHdz]

Originally Posted by R7237

Would you recommend I install both the SV-GPS-2020 and the GPS-175?
I figured with an ARINC adaptor, I would provide the GPS data from the GPS-175 to the AFS 5500 and the SV-GPS-2020 would don't be needed,,,, GPS data to the transponder as well.

In aviation I am a belt & suspenders kind of guy so IMHO yes.

The 2020 is a simple connection for your transponder and you can have the 175 as a backup. You have to connect the 175 directly to your transponder (not through the SkyView/AFS) for it to be used as an ADS-B source. But that is the great thing about experimental, you can do whatever is best for you.

FWIW I have the exact same setup but with a G430W instead of the 175.

[SMRacer]

Originally Posted by R7237

Would you recommend I install both the SV-GPS-2020 and the GPS-175?
I figured with an ARINC adaptor, I would provide the GPS data from the GPS-175 to the AFS 5500 and the SV-GPS-2020 would don't be needed,,,, GPS data to the transponder as well.

You do not need the GPS-2020 if you have the Garmin GPS 175. The Garmin can supply the signal for ADSB out. But you would still need a GPS source for the AFS. You could however, get by with a SV-GPS-250 (instead of the 2020) for the AFS display. The GPS 250 can be found used for about $50 from those upgrading, so you could save some money that way. I don't think you can use the Garmin 175 GPS signal for the AFS 5500.

[BobTurner]

It sounds like you have already purchased an EFIS, but, if not, maybe you should look at GRT. They have a beta-test going with gps approaches using their $500 gps intended for adsb-out use, plus all the rest of the software and databases inside an HX EFIS (not sure if their newer efis units also support this). There is no TSO, and they clearly state this is for practice use under vfr. Any approval for ifr use is up to the owner to obtain.

[R7237]

Originally Posted by BobTurner

It sounds like you have already purchased an EFIS, but, if not, maybe you should look at GRT. They have a beta-test going with gps approaches using their $500 gps intended for adsb-out use, plus all the rest of the software and databases inside an HX EFIS (not sure if their newer efis units also support this). There is no TSO, and they clearly state this is for practice use under vfr. Any approval for ifr use is up to the owner to obtain.

Already have the AFS 5500, otherwise would consider it.

[Carl Froehlich]

Originally Posted by SMRacer

You do not need the GPS-2020 if you have the Garmin GPS 175. The Garmin can supply the signal for ADSB out. But you would still need a GPS source for the AFS. You could however, get by with a SV-GPS-250 (instead of the 2020) for the AFS display. The GPS 250 can be found used for about $50 from those upgrading, so you could save some money that way. I don't think you can use the Garmin 175 GPS signal for the AFS 5500.

Two points:
- Yes, you still need the GPS-2020 or GPS-250 if only for backup.
- Yes, perfectly ok to use the GPS-250 instead of the GPS-2020 if you are using the Garmin box for the serial GPS output to the XPDR for ADS-b out. I did this on my current RV-8 (GTN-650 with dual SkyView HDX displays). As a side benefit, the GPS-250 position locks much faster than the GTN-650 and I told faster than the GPS-2020. It is not WAAS, so may differ from the GPS-250 by a couple of feet (in other words no practical difference as you don?t use either for IFR approach).

Carl