gypsywagon wrote:I asked about the garmin 500 to come and you Bigrenna where the one to turn me on to the Trio Pro. Just sayin!

Let me know where to send your check back...

I just reread the orig question again... For those that dont understand, some DG's output a heading signal driven by the bug that can be used by an autopilot. The question is 1) does the G5 output this signal, and 2) if so, can the Trio use it for a heading source to drive the A/P. In other words, fly just by the heading bug irrespective of the GPS.

I looked thru the install manual again and there is no mention for unsupported A/Ps, however the G5 does export the signal when used with the GAD29 and GMU11. I guess this is a question for Trio. If someone wants to call this would be interesting info.

I'm very interested in the outcome of this as well. I was anticipating installing a GFC500 next year just to keep it "all Garmin" and avoid weird compatibility issues, but missed one little detail - the GFC500 isn't AML'd back to 182's of my vintage, and I don't think Garmin has plans to do it. Trio takes ARINC429 in which the standard GAD29 outputs, so hopefully this is as simple as it ought to be. Of course, Garmin has been known to lock data communications to their own equipment.

I sent Trio an email, will post back any response.

From what I've heard and read, Garmin doesn't always play well with others.
Maybe it'd be best to just go all-Garmin.
I've got a G5 now, and tentatively planning on a GDL82 when the time comes.
If my old Narco Com 810 radio or AT150 txp go belly-up,
I'll probably replace them with Garmin units.
Garmin's good stuff, and they've been around a long time now.
I don't see any sign of that changing.

I am using the RS232 out from my GTX 335 to share the WAAS with the G5. Also to the ELT.

The issue with total Garmin in the AP world is that their low cost model (GFC-500) only covers specific versions of aircraft lines, so for example C182E and up. Nothing for the early 182's like mine, 180/185 crowd, etc. I haven't heard back from Garmin yet on whether they will expand the AML's.

I did get some good info from Chuck at Trio today though, and told him I'd be re-posting the salient bits of our conversation here. This is what I've learned:
- The Trio gets all of its steering via the ARINC bus coming out of the Navigator. This is why GPSS/GPVS work for approaches now.
- Units like the Aspen or G5 transmit their selected course features through the same bus, so it's more or less a matter of interpreting the messages and doing something with them.
- Trio has been attempting the Aspen integration first, however G5 also uses the same message labels, so if one works they both should.
- They are working on installing this with an Aspen to test in a 182 right now.
- No firm ETA, but he thinks they will have the software update in the Trio to support G5/Aspen lateral course steering by mid summer. This is largely dependent on the feds in Chicago, however they've been responsive so far.

So, this is great news! If you can wait a few months for the feature to exist, you should (theoretically until proven) have G5-driven Trio autopilot capability. It'll use the same GAD29 box you'd interface to the navigator with, so you don't need the 29B. What I don't know yet is if you could drive an autopilot using G5+GAD29 alone (no navigator) or if they'd even test that functionality, but it's all the same bus. Will update back when I get an answer to that one.

Here's an AOPA online report about more airplanes being added to Garmin's GFC500 autopilot STC.
The way I read it, it sounds like the G5 drives the autopilot, navigator input is optional.
From the article:
"When the GFC 500 is integrated with the G5, the electronic flight instrument provides input and display of altitude preselect, heading, vertical speed target, airspeed target, and Flight Director command bars for the autopilot. An optional GAD29 adapter allows the GFC 500 and G5 to interface with select Garmin GPS or VHF navigators, Garmin said."

https://www.aopa.org/news-and-media/all ... 0405epilot

Yes Hotrod, that's how I understand it as well. It's a good unit, you just need to make sure it can be installed in your aircraft. Garmin's may have tighter integration in the aircraft you can actually put it in, though it's more expensive. The Trio will miss a feature or two from the G5+GFC setup (at least temporarily - wait a few months and update the software), however it's cheaper by itself and the STC is far more applicable to this crowd since they covered 172, 175, 177, 180, 182, 185 and Piper PA-28. The downside there is that you *must* have a navigator to interface with the autopilot, you can't just plug the G5 into it. Word I got is that theoretically it'd work that way since data is data, but the STC doesn't cover direct G5->Trio so far.

lefoy84 wrote:I am using the RS232 out from my GTX 335 to share the WAAS with the G5. Also to the ELT.

I wanted to do that with my GTX 345 WAAS, share the GPS with my ELT - but was told by the Avionics shop it would not work...

In 1956 Mr. Maxwell bought a C-180, which we flew mostly IFR. The autopilot would follow the bug on the DG. The autopilot would also track the CDI. But since I was too short to see out, he let me do that. It was rocket science.

Kind of a thread drift, but had anybody been able to successfully get a nav radio to drive the vor/loc/gs indicator function of the G5? I know it can do it when paired with the nav radio in the newer garmin GPSs, but I was wondering if there was any other radios it could also be paired with. No help in the Garmin manuals, so I'm assuming no? Figured it can't hurt to ask... thanks!