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Avionic options for the new build

Carl Froehlich

Well Known Member
All,

I’d be interested in thoughts on my three listed options. Background; this is my fourth build (RV-10). All the builds have dual SkyView EFIS displays (as will this one). The builds also revolved around the GTN 650 as the TSO navigator. I’m not thrilled with the 650 (price or ease of operation) but at the time of the build it was as the least bad of the available options.

For this build however I have new choices to consider. Here are the three options I came up with (and the associated ACS list price for each option):
1. GTN 650 with the Dynon radio as Comm #2. $13,300
2. GNC 355 with the Trig TX-56A as the NAV/LOC/GS receiver and Comm #2. $11,500
3. GPS 175 with the Trig TX-56A as NAV/LOC/GS receiver and Comm #1, the Dynon radio as Comm 2. $10,930

Side notes:
- I require ILS/LOC/NAV capability.
- I will be again use the integrated SkyView XPDR.
- Indications are the Trig NAV/Comm will integrate with the SkyView just like the Dynon radio.

I have not flown any GPS navigator other than the GTN 650. My first question is can I consider the GPS 175 to have the same GPS navigator capability as the GTN 650? Same question for the GNC 355?

Beside the obvious price advantage, what am I missing?

I have considered and rejected other common avionic options like the Garmin Comm and NAV/Comm as well as the Avidyne navigator - so no need to rehash that.

Carl
 
Carl,

You know my choice is number 2. If the navigator fails you still have the Trig ILS option. Also if you have to power down to save battery in alternator failure, the Trig TX56 takes less battery power to operate and on battery you still have the dynon gps on the sky views. Trig will get you to an approach and dynon will get you to the Initial fix. The 650 is single point failure. To each his own cheers
 
Hi Carl

I have Dual Dynon Displays, Dynon Coms and Garmin 175 in my RV10.

I have not flown with the Garmin 650 but the only item I miss on the Garmin 175 vs my previous Garmin 430 is the vertical navigation planning and the fuel planning page. The 175 performs great on the RNAV approaches.

Steve
 
Thanks for the feedback.

Now two more questions:
- Those of you flying with the 355 or the 175 and a standalone VOR/LOC/GS receiver, when doing an ILS approach does the 355/175 display the full approach on the EFIS like the 650? I know to shift the HSI to the ILS receiver the approach, but what about the use of GPS for such things as IAP, Holds, Missed Approach?
- Is the only difference between the 355 and the 175 being the 355 has a Comm?

Carl
 
Here you go Carl,

Yes only difference between 175 and 355 is the Comm capability. Your first question is a little trickier to answer. Short answer is not exactly. The 650 retains the approach when switching between GPS and LOC because the “source selection” on the dynon remains the same. When you change the source selection over to Trig TX56, you loose the mapping feature that was being displayed while using the 355. Here is the work around I mostly do, I upload my flight plan into both the dynon skyview via WIFI and Garmin 355 via Bluetooth. ForeFlight lets you load procedures into your flight plan that gets transferred to both. If I’m shooting an ILS with the Trig 56A, my source selection is NAV 1 (brings up CDI) for the Trig BUT retains the mapping feature from the Dynon on the MFD. That gives you the tracking you are looking for. If I need to go missed I just switch the source selection to Garmin 355 and my missed approach course shows up on the MFD. interesting thing is I can program in a ILS/VOR/LOC into the 355 but it’s not legal to fly the magenta needle on those courses. But it flys them beautifully or ahhhh that’s what I heard.
 
Time to move on

I gave up VOR/ILS when I installed a GPS175 and removed the Garmin SL30.

But if you can't live with that, keep in mind that the GPS 175 device is an input device only. (IMO) The screen is too small to be really viable. My 175 displays on my AFS 5600. And thus I am happy with that particular combination.

The GNC 355/GNX 375 suffer from the same limitation. Again only in my opinion.
 
For this build however I have new choices to consider. Here are the three options I came up with (and the associated ACS list price for each option):
1. GTN 650 with the Dynon radio as Comm #2. $13,300
2. GNC 355 with the Trig TX-56A as the NAV/LOC/GS receiver and Comm #2. $11,500
3. GPS 175 with the Trig TX-56A as NAV/LOC/GS receiver and Comm #1, the Dynon radio as Comm 2. $10,930

Side notes:
- I require ILS/LOC/NAV capability.
- I will be again use the integrated SkyView XPDR.
- Indications are the Trig NAV/Comm will integrate with the SkyView just like the Dynon radio.

Carl

Carl,
Personally I’m an option 3 guy. But that may be because I have almost that exact setup. I do have a question or two though…

Why Dynon Comm as Comm 2? Do you believe the TX will have the same APT features as the Dynon? I really love the “hot” buttons. To me, Dynon at Comm 1 makes more sense. As I’m writing this though it comes to my mind that I have a Skyview Classic and that may be the difference… I am not familiar with all of the touch capabilities.

Either way, once installed would appreciate pics and PIREP on TX 56A
 
Did you consider an avidyne navigator?

I have dual dynon displays in my rv7 and they play very nicely with avidyne.

I’ve flown with the garmin 650 and 759 and don’t like the levels of menus in basic operation and the touch screen in turbulence. The avidyne is much more usable.

David
 
To the specific questions:
- Avidyne. I went around the tree deciding between the Avidyne and the GTN 650 on the last build. I was attracted to the Avidyne as the reviews I found said it was far less clunky to operate than the 650 (as in button smashing to make it play nice). But it came down to “the devil you know” and I went with the 650.
- On the Dynon radio as Comm #1, that is what the current owner of my first RV-10 does and he loves it (GTN-650 and Dynon radio). Of note, the SkyView does not care if the Dynon radio is Comm #1 or #2 (that is an Audio Panel selection), it will talk to it anyway for automatic feeding of frequencies. I hear the Trig NAV/Comm will talk to the SkyView in the same manner, but I think that is a SkyView software update or two away.
- On the 355 or 175 display area, I consider them on par with the marginally bigger 650 display - as in close to useless for moving map, weather or contact information. The SkyView does these functions far better than the 650, or for that matter the 750.

Scott, on using the 175 or 355 and the Trig Nav/Comm for an ILS approach. If I retain the SkyView on the 175 or 355 for the flight plan source, selecting the HSI to NAV should not change the ILS approach displayed on the SkyView - should it? The nice magenta lines should remain while the HSI shifts to green, like the 650 does. Your thoughts?

Carl


Carl
 
Hey Carl,

Yes, If you have the Dynon as "source" select and change to Nav 1 (TRIG 56) on the source select to bring up the CDI green needles, the Dynon Map still shows your course or/and approach. If you hit source select for the Garmin 355, it will bring up whatever course is in the Garmin at the time. So I just download from foreflight and load both Garmin 355 and Dynon with my flight plan. THat way I have the option of doing a GPS or ILS approach, if your using green needles anyway, you only need the flight plan to get you to your Initial Fix, then its green needles and altitude the rest of the way via VOR or ILS (w/glideslope). My glideslope fromt the TRIG to DYnon has been great, manually or autopilot flying. If you use the Dynon Autopilot for either GPS or ILS, "you need to be level for the Glide slope to lock on". If your decending and arm the LNAV function, it will blow past the glide slope, you need to be level for the LNAV to activate. IF you remember to level prior to intercept of the GS, it will lock everytime and fly the entire approach. Works really well. Let me know if that makes sense. Or PM to give me a call and discuss.
 
Bear in mind that the Trig Nav/Com has only the SL-30 serial interface and does not have an ARINC 429 link. I don't know if that is significant with the Skyview - Garmin equipment likes the ARINC feed via a GAD 29.

GPS175 (etc) does not quite have all the functionality available in a 650, if you only fly IFR occasionally it may not be a factor. The missing features are in the details (and I can't remember exactly what) but in some cases there is more workload with a 175 to do stuff that the 650 will automate. 355 (& 375) have same GPS functions as the 175.
 
Carl,

I would give Rob Hickman at AFS a call and ask his opinion. He flies with both a Garmin and Avidyne in his RV-10.

I know AFS has plans more more tightly integrated features with the Avidyne. Since Garmin went with proprietary APIs in the GTN series, that won’t happen with Garmin products. I don’t know what Dynon’s plans are for doing the same with the HDX.

I know I’m a bit biased, but I recently upgraded my AF-5500s to AF-6600s. I really like the improved performance and screen size.

Bob
 
Thanks Bob. On the RV-8 build I ruled out the Avidyne and have not had reason to review that decision - for now.

Frogman 208 sent me some data on using the 355/175 and a standalone NAV/Comm for the ILS approach. It appears that the 175 and Trig combo will function like the 650 does in my RV-8 for providing the approach, holds, missed approach tracks and such. Here the flight plan for the SkyView is selected to the 175. Once on the approach the HSI will be shifted from the 175 to the Trig Nav/Comm. Frogman is going to provide more information as he checks details.

Carl
 
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