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Stroh21

Well Known Member
Hello VAF!

The project I'm working on while deployed over the next 4 months is piecing together a panel upgrade for my RV-8A. The goal of the upgrade is to add some IFR capability and revise the layout of the panel. Any and all advice is welcome. I have a limited budget for this project, so I'll be looking to the Classifieds on VAF and E-bay to acquire these parts. Any advice on acquisition is also appreciated! :)

CURRENT EQUIPMENT:
Basic 6 Pack
King KT-76A Transponder
VHF Radio - Type Unknown
Trutrack 2 Axis Autopilot
Garmin 796
Dynon EMS

PLANNED EQUIPMENT FOR IFR PANEL:
Dynon D10A EFIS - Already Purchased
Dynon D10-EMS
Garmin 796 - (Can I certify this myself for /G operations?)
Garmin GDL-39 3D to improve the 796.
Garmin SL-30 or King KX-155 (Not sure if King will work with the EFIS?)
Garmin GMS-240 (or do I need a 340 for IFR flght?)
King KT-76A Transponder (Connected to the EFIS for altimeter setting?)
Trutrack 2 Axis Autopilot (Will this talk to the Dynon EFIS?)
Dynon HS-34 (Do I need this?)

DESIRED OUTCOME:
1. Legal flight in IFR. AKA: Ability to takeoff with a low cloud deck. Not looking to fly in moderate weather.
2. Add second radio for safety
3. Improve the 796 with the GD-39 3D so it has the backup ADI.

Am I missing anything? Sorry for the long post and thank you for the help up front!!!

Matt
 
Stroh21 said:
Hello VAF!

Garmin 796 - (Can I certify this myself for /G operations?)

Matt
Click to expand...

Sorry, the FAA won't let handheld GPS's play IFR. What some people do is install an SL30 and then fly direct with the handheld GPS and use the SL30 for the approach. That assumes there is an ILS where you are going.
 
My two cents:
Although not strictly required by FARs, IMHO it's crazy to contemplate IFR without some basic backup flight instruments with independent power. Is your current AI vacuum driven? If so, keep it and the ASI and altimeter as backups.
You don't need an audio panel; get or build an intercom with inputs for the radio(s).
I'm assuming you do not want to get into IFR GPS due to the cost. It's high.
The SL-30 is a great nav radio, you can tune in an ILS and a VOR at the same time. You'll need to check and see if the Dynon can display both, I know the GRT will. Of course the SL-30 is no longer made, you'll have to find a used one.
While going the way of the dodo there are still ILS's that need either an ADF or MB (assuming, again, no TSO'd GPS). Used MB receivers are only a few hundred dollars. If your local ILS uses a VOR cross fix for the FAF, the SL-30 is all you need. If your home airport has an ILS that needs an ADF too (there are still quite a few like that), you may need to look at a used, older TSO 129 GPS to use instead of an ADF. That would give you more options, too.
I cannot answer the TT question. But take a look at Trio, I think it's a better value for the money. Both of these autopilots must be fed with an RS-232 signal from a GPS, or from an EFIS that generates a signal from heading, VOR, etc., that looks like a gps, if you want them to track a course. Either will work as an altitude hold, wing-leveler, with no other inputs, if that's all you need.
Are you based, or flying into, an airport under class B or C, or the B mode C veil? e.g., will you be needing ADSB-out? Or, do you want it?
Yes, you can get altitude encoding out of the EFIS. But you need to double check if the KT-76A can read serial (okay) or if it needs gray code, in which case you'll need to check and see if the Dynon provides that. e.g., make sure they will work together.
Sorry there's more questions here than answers. But there's lots to think about.
 
going off the top of my head here but I am almost sure the 76A is a gray code unit. dynon does make a box to convert them, but if you already have mode c i would just leave it as is for now.

as stated, to get /G you must have a /G approved box. by the way, going direct with out a /G box is not legal. but I have told many controllers that I can fly a heading/direct when able really, really well wink wink.


bob burns
 
n82rb said:
as stated, to get /G you must have a /G approved box. by the way, going direct with out a /G box is not legal. but I have told many controllers that I can fly a heading/direct when able really, really well wink wink.
bob burns
Click to expand...

What is legal is a radar vector. So if you're going to xyz, even if it's 200 miles away, you call ATC and say,"How about a radar vector direct xyz on maybe, like, a heading of 136?". They know what's going on, but often say okay.
 
As others have said, you can fly legal IFR with the SL-30, but you would only be able to fly some (not all, as mentioned) VOR and ILS approaches. I think you would be MUCH better served by a Garmin 400W or 625 IFR GPS and no NAV radio (better with both, but if I was picking one, I'd go with the GPS). This would allow you to fly all GPS approaches, both precision and non-precision.

With your proposed panel, there is no need for the HS-34, as that is an ARINC converter with other easy-to-access buttons. If you get an IFR GPS as mentioned above, you would need the HS-34.

Recommendation: put the EMS close to the EFIS, as you will likely use that screen for HSI in either setup.

The TruTrak can fly off the IFR GPS or it should be able to fly off the SL-30. I'm not sure if the D-10A will drive the GPS, but you don't need it to. It can drive itself (functions depend on the model).

The GMA-240 is an audio panel without a marker beacon. The 340 has a marker beacon. If flying only an SL-30, you may want the marker beacon. If you go with a 400W or 625, you don't even need an audio panel. You may want a second radio, even a handheld with a way to plug into an external antenna would work as a backup.

Feel free to call me if you want to discuss the options. I am international this week, so calls would need to be short. I am back stateside Sunday afternoon for longer calls.
 
Thank you for the inputs!

Hey Guys!

Thank you very much for the inputs. I apologize for the slow reply. Work has been very busy the last several days.

The discussion has gotten me thinking about going with a GPS instead of the VOR radio. The C-130 I fly isn't GPS approach capable, so I'm used to flying ILS approaches at AF bases. I probably need to open up my scope to getting a GPS. The budget doesn't allow for it just yet, but maybe I need to bite the bullet and save up for a Garmin 430W.

I need to also research making my own Comm Panel. Sounds like a fun project! Do you guys recommend any books or websites on this topic? I graduated as an EE from college, so I wouldn't mind brushing off those brain cells.

I also liked the idea of integrating a hand held radio into the comm system. Great idea for use as a second or third radio!

I plan on keeping the Vacuum ADI and a combo Airspeed/Altitude instrument on my panel as a backup system to the Dynon. I like double and triple redundancy. It is a C-130 thing :cool:

Thank you again for the discussion. I'm still interested in hearing others inputs. For those offering advice over the phone, I probably won't be in a good position to call until February if the offer is still open then.

Rounds on target! Fire for effect!
Matt
 
GPS thoughts continued...

What is the community opinion of the Garmin GNC 300XL? It seems to fill the IFR GPS requirement previously mentioned and adds a second comm radio for $1600ish. I know it doesn't give me a precision approach capability, but I don't plan on needing to fly in weather down to minimums :)
 
Stroh21 said:
What is the community opinion of the Garmin GNC 300XL? It seems to fill the IFR GPS requirement previously mentioned and adds a second comm radio for $1600ish. I know it doesn't give me a precision approach capability, but I don't plan on needing to fly in weather down to minimums :)
Click to expand...

It was a fine radio in its time, but you have to wonder how long Garmin will support it. It needs an external annunciation box. As a TSO 129 box it is only approved as 'supplemental' navigation, e.g., you must have a VOR too. However it can sub for MB or ADF if required on most ILS approaches, as well as give you LNAV minimums on gps approaches. I think it's a good low cost approach. The only question is ADSB-out. Will you want or need it in 4 years? If 'yes' then you'll need another gps, one meeting ADSB requirements. The sum of the Garmin 300 plus another gps for ADSB plus a nav-com may be more than a New Garmin 420W.

As to the audio switch panel: I built my own intercom/switch panel and as a EE I'm sure you can too. Parts are cheap, the cost is 90% your (free) labor! And you get what you want as far as control. I built mine using Op amps which only need a single sided power supply (about $0.25 each).
 
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Good to know about it being a supplimental radio and needing the VOR.

Any inputs on the King KX 125? I know it is an older radio, but it seems to fill the same role as the Garmin SL-30. What am I missing on this one?

Thank you again for helping answer silly questions!
 
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