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jump4way

Well Known Member
I have been searching the forums and have found tons of information on this topic but none that quite seem to meet my particular setup and questions. I'm looking for thoughts on the following setup.

GRT Horizon EFIS and EIS
Dynon D10A for backup with battery backup and for autopilot
GNS 430W primary com and nav
Icom A210 second com
GMA 240 Audio panel

This is going in a 4. I am curious about comments about the Dynon D10a as backup versus traditional steam gauges. The other option I was considering in the way of steam gauges is an AS, Alt, and TC for backup. Eventually a TruTrak autopilot. Obviously space is limited.

It seems to me that the dual glass setup with separate type Efis would guard against the software fault. With battery backup on both that would guard against electrical failure for a time. That leaves the only real fault area that I can see being a pitot static failure. Am I missing anything? Is the dynon AP a reasonable alternative to the TruTrak lines?

Andy
 
Looks to me like you have the dissimilar redundancy covered - that's good. I'd have no problem backing up the GRT with a Dynon for attitude. I'd strongly consider adding another GPS - even if it is just a puny OEM hockey puck, it will give you good position info as an emergency if the 430 dies (otherwise, you have no Nav information other than what ATC gives you on the radio. I like to keep the Autopilot separate from the primary EFIS, and you've done that - the Dynon A/P is experiencing some early growing pains, as reported here, so you have to decide if you think it will reach an acceptable level of maturity by the time you fly it - that would be the decision point for me between the Dynon and Tru track (The Tru Trak integrates beautifully with the GRT equipment BTW - drives from the EFIS just great!).A lot of us have gone with a small backup battery for the EFIS so that it can be powered on before engine start and not reboot when you hit the starter switch - that also gives you good backup power in case both your alternator and battery die (or the main bus shorts).

Paul
 
The only thing I would add to Iron's comments is that a Dynon seems overkill for a back-up. I would get a Trutrak autopilot as they work very well with the GRT EFIS, and then an attitude instrument of your choice. If you stick with the Dynon ask them how much integration testing they have done with a GRT EFIS driving their autopilot. You would like them to say they have flown that combination for several hours and have had the GRT drive the autopilot down to 200ft on an ILS.

Do you need an audio panel? I think you could get away with something much more simple? I think a huff & puff ASI and altimeter (if you have room) adds a lot of redundancy, even if you go with a Dynon as back up.

Pete
 
dynon D6 as backup?

I plan to use the Dynon D6 as a backup to the AFS system. I like the dissimilarity, and you get a whole 6-pack worth of backup for only $1600. I can live without NAV indicators on the backup.
 
Thanks for the great replies. As for Paul's comments, I do have a 496 and coincidentally an AV8or that I could use as a back up GPS but finding a place for it in the 4 panel seems to be my problem. I'll keep playing with the layout and see if I can figure anything out. I do seem to have all of my eggs in one basket regarding navigation. I suppose if it won't fit in the panel I can at least keep one of them in the aircraft for emergency use. Is the backup battery that you are using the one sold by GRT or is it some homemade version?

As for the Dynon autopilot, it sure seems to require a lot of tinkering to get it right from what I have read. I'm really the type with the patience to tweak settings for a long duration and enjoy it. Maybe another option is to go with the D6 and the TruTrak AP setup. I of course then lose the added features of the D10a, but would it be more bang for my buck in the long run?

I don't know that I do actually need an audio panel. When I originally began planning having an audio panel it was to have the ability to receive marker beacons. I have since chosen and audio panel without that ability. I also plan to have dual comms, would that not require an audio panel? Maybe a good stereo intercom would be the way to go with an auxiliary input for an audio source if that is possible with dual comms. I don't know if I would be able to take advantage of the EFIS audio warnings without an audio panel or not. Anyone know the answer to that?

Thanks again for all of the great feedback.
 
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Pete,
The EFIS + AP from us is less than a simple TruTrak AP, so it's much, much less expensive to go with a Dynon as an attitude backup as well as an AP. Which makes the Dynon not so much overkill ;)

As for us being driven by the GRT, basically no testing has been done. Unlike TruTrak, we support Localizer and VOR right in the box, so we can fly an Localizers without needing GRT to convert from an Localizer and then "lie" to the TruTrak about being on a GPS approach. Additionally, we support flying a HDG bug right in the EFIS, which TT doesn't do unless the EFIS lies to it about it being a GPSS source. Because of this, there isn't much reason for us to accept input from other EFIS systems, since we are the EFIS system.
 
dynonsupport said:
Additionally, we support flying a HDG bug right in the EFIS, which TT doesn't do unless the EFIS lies to it about it being a GPSS source. Because of this, there isn't much reason for us to accept input from other EFIS systems, since we are the EFIS system.
Click to expand...

I'm not sure it makes much difference to the pilot what "kind" of source the autopilot thinks it is seeing, does it? On the GRT, you put the A/P in heading mode, turn the knob, and the airplane follows the heading bug. This is what yours does as well...no? the TT doesn't care if the steering commands from the EFIS are derived from GPS, VOR, LORAN, or whatever - they are just steering commands.

Andy - the Aux battery system I have is just one I buitl myslef, long before GRT started offering there's. It's eally handy that the GRT boxes have three power feeds - very easy to incorporate multiple isolated sources.

Paul
 
RV-4 Panel

I think your panel will do what you want it to. I agree with the comment about a backup GPS. Radios fail.

A couple of years ago I did what you are doing now. I wish I had bought a 430 now because many approaches (at least in my area) are now requiring DME or GPS (certified). Anyway, here is what I ended up with:

Audio panel (for the marker beacons and 2 coms)
SL-30 Nav Com (Includes VOR/ILS)
SL-40 Com
AFS-3500 EFIS with backup battery
TT 2 1/8" ADI for a backup horizon with a backup battery
TT Digiflight II VSGV which will do everything you could possibly want when driven from the EFIS
Garmin 496 for GPS input into the EFIS to drive the map and for HSI functionality (Powered by the aircraft but has backup battery)
A steam guage ASI 2 1/8"
A real magnetic compass

I also carry a Garmin 195 as backup for navigation.

It all comes down to four things to ensure your survival when you are IMC: altitude, airspeed, attitude, and location. You should set up your system so that when there is a failure you have enough backups to know these things. There was another thread recently about failure analysis. Takesome time to think things through, because you don't want to be doing this in the soup.

So, for altitude I have my EFIS as primary, and my GPS altitude as backup in an emergency, and also my portable 195 as backup to the backup.

For airspeed primary is the EFIS, then the steam gauge, then GPS speed (if the heated pitot ices up.)

For attitude, I have the EFIS as primary, THE AUTOPILOT as secondary, the ADI as backup to the autopilot, and I have practiced using only the GPS 496. It is totally possible to survive using only the 496 in IMC if the turbulence is not extreme. I like the ADI becuase it also doubles as a VSI, and if it has GPS input is good as a heading indicator.

For where you are, have a backup GPS. I have the NAVCOM as well, but the GPS is more accurate and easier to use.

I got my instrument rating a little over a year ago in a steam gauge airplane. I gave Doug Rosendahl a call to discuss flying IFR int he -4 after I saw the article in Kitplanes on his Rocket. (The article mentioned that he flew his -4 IFR regularly.) He told me, and I believe it is very good advice that the first step should you figure out that the EFIS has failed (or any other failure for that matter) should be to activate the autopilot so that you can get reoriented and figure out what to do. So whatever you decide, get an autopilot that you have a lot of faith in that is separate from your primary EFIS and will not have any system interconnection in common.

Another piece of advice I would give you is that in a -4, you need to be really organized. I use airchart systems for IFR enroute charts. I really like them because no matter where you go, just grab one spiral bound book and off you go. Hauling a lot of approach plate books along is no fun on a long cross country, so I have been watching the other threads on this site about the ebook readers etc for approach plates. I think that will probably be what I do once there is some mileage on them. AFS has approach plates that are georeferenced for the EFIS which are nice if you can do multiple sreens, but I don't use them on the approach becuase it wipes out my single screen EFIS display.

My 2 cents. YMMV
 
Most others have pretty much hit everything spot on...especially in an RV4. The There is not a whole bundle of extra room on the panel, so what you've got is a pretty nice setup. Not too long ago we did an RV-4 very close to what you're doing and it works wonderfully, the customer flies it hundreds of hours per year with lots of actual IMC.

I would say the AP would be something to look at very seriously as Brent stated, the TruTrak plays nicely with the GRT and is well proven to fly nicely either from the GRT or directly from the GNS-430W and will fly coupled GPS approaches from either one. GRT and TruTrak each spent a lot of time on the interface between the two and there is really no reason to bother considering other unproven and/or untested combinations. Also, since WAAS GPS approaches now outnumber ILS approaches by a good margin, and the goal of the FAA is working towards having a GPS approach at most pulished runways it makes good sense to have a system that will track and fly WAAS approaches.

The little Dynon is an excellent box and we install a good number of them as backups to many different systems (GRT, AFS, Garmin, etc..). It's backup battery has been very robust so I wouldn't worry too much about that.

Given your space contraints and equipment choices, I think you've made good decisions....and I wouldn't have a problem recommending that panel. By far, the large majority of IFR RV panels use a similar set of equipment as what you've chosen so you're heading in the right direction.

My 2 cents as usual!

Cheers,
Stein
 
Ironflight said:
I'm not sure it makes much difference to the pilot what "kind" of source the autopilot thinks it is seeing, does it?
Click to expand...

My point was that we don't need to get commands from the GRT EFIS. We naturally fly the Localizer and Heading bugs. We don't require an external EFIS to do those things like TruTrak does. Since TruTrak can't fly a heading or a Localizer without an external device attached, the integration with GRT is a big deal, but not so much when the AP already does all those functions.
 
dynonsupport said:
My point was that we don't need to get commands from the GRT EFIS. We naturally fly the Localizer and Heading bugs. We don't require an external EFIS to do those things like TruTrak does. Since TruTrak can't fly a heading or a Localizer without an external device attached, the integration with GRT is a big deal, but not so much when the AP already does all those functions.
Click to expand...

I understand your point - your A/P IS your EFIS, essentially. Of course, you do need an "external device" (an ILS receiver) to provide your guidance. The TT will fly a heading without anything else attached BTW - at least my Pictorial Pilot will.

Paul
 
Advantage of similar equipment

jump4way said:
I have been searching the forums and have found tons of information on this topic but none that quite seem to meet my particular setup and questions. I'm looking for thoughts on the following setup.

GRT Horizon EFIS and EIS
Dynon D10A for backup with battery backup and for autopilot
GNS 430W primary com and nav
Icom A210 second com
GMA 240 Audio panel

This is going in a 4. I am curious about comments about the Dynon D10a as backup versus traditional steam gauges. The other option I was considering in the way of steam gauges is an AS, Alt, and TC for backup. Eventually a TruTrak autopilot. Obviously space is limited.

It seems to me that the dual glass setup with separate type Efis would guard against the software fault. With battery backup on both that would guard against electrical failure for a time. That leaves the only real fault area that I can see being a pitot static failure. Am I missing anything? Is the dynon AP a reasonable alternative to the TruTrak lines?

Andy
Click to expand...

Andy,

I will throw you my logic since I am right in the middle of my design. I like the bang for the buck of the Dynon equipment so I designed around that as my EFIS. I understand the logic of dissimilar equipment and possible failure modes. I am going Dynon 180 EFIS/EMS and the Dynon 10A as my back up attitude reference. It think the "software bug" effecting both item at the same time is so remote I just don't consider it. My time in actual IFR will be very little of my over all flight time. I fly for a living and the time spent in actual IFR is only a fraction of total time.

The Dynon combo gives me display agility, I can have the D-180 with EFIS/EMS and the D-10A with an HSI display up or I can have the D-180 all EFIS and run the EMS display on the D-10A. This "display agility" benefit far out weighs the remote possibility of both EFIS displays going out at the same time. They each will have separate battery back ups, so it would have to be some software bug that make them both fail.

The rest of my panel is much like yours G-430W, G496, IC-210, this gives redundancy in Comm, EFIS and GPS.

Cheers
 
Andy,

I long ago chose the Dynon D-10A as my set of "backup gauges." My primary displays are GRT Horizon 1 EFISs. In my airplane, the little Dynon will literally be a stand-alone instrument, not connected to anything but a magnetometer and a power source. (If I had waited a bit longer, I'd probably have bought the new D6, but the D-10A has some good stuff like the ability to display checklists, which I think could be useful...) Anyway, I agree with the philosophy that it's prudent to use different manufacturers for your two EFISs. If you have the choice to do so, why not?

Other thoughts:

1. Remember that if your engine info will be displayed on your GRT screen(s), you can stash the EIS box out of sight and free up some panel space (if you need it for something more important).

2. My Dynon has an internal backup battery. My GRTs can be switched to a 7.2 Ah battery. You can avoid the voltage dip to your EFIS that occurs during engine start with either Paul's method (a separate power input from a backup battery), or by using a power stabilizer like the one offered by TCW Tech.

3. As the others have said, the TruTrak autopilots interface very well with GRT EFISs and Garmin products. I have no first-hand experience with the Dynon autopilot, so I cannot give advice there. I prefer working with thoroughly tested and proved solutions when I'm installing mission-critical systems. Not to say other solutions aren't adequate or even great, but I know what definitely works.

4. If you have two comm radios, I think you will be happier if you have an audio panel. It just makes life so simple -- plus it allows you to easily add inputs/outputs for whatever strikes your fancy later: XM/Sirius music, iPod, video camera, etc.

Just another $.02. (Keep this up and you'll be rich!)

Sounds like you're off to a great start with your panel planning. Best of luck.
 
A thought

Following Paul's Note about the Trutrak.

I have a D100 a Pictorial pilot and a 430W as my IFR tools. I find that I almost never hook the TT to the 430W to provide steering. Personal preference but I kinda like them seperated while in the soup. I guess I'm nervous that if the 430W quits, what does the TT do.

That and I have the mental note of where i was driving the airplane because i dialled the heading into to TT manually.

FWIW

Frank
 
N999BT, Stein,

Is there a significant difference between the GRT and AFS when having it drive the TT auto pilot? Does the AFS generate steering from an analog source like the GRT does?

schu
 
frankh said:
I have a D100 a Pictorial pilot and a 430W as my IFR tools. I find that I almost never hook the TT to the 430W to provide steering. Personal preference but I kinda like them seperated while in the soup. I guess I'm nervous that if the 430W quits, what does the TT do.
Frank
Click to expand...

Does anyone know what will happen in this set up above of Frank's, if the 430W quits?
John
 
I can tell you that if I'm driving my TT Pictoral Pilot direct form my 430, and the 430 quits putting out RS-232 sentances, the Autopilot just keeps going in a straight line on it's last heading. Pretty simple.
 
AFS and TT

The AFS drives the TT autopilot based on bugs or steering commands from a navigational input like a 430 or 496. It uses whatever you have selected for the HSI display. I would assume that is the same with GRT, but I have no experience with GRT. The autopilot feature of the AFS works well. I know they have spent a lot of time working with TT to get it right.

On my airplane it will fly an ILS beautifully. I am happy with it.
 
Andy,

I would think about a handheld GPS in that mix. With its built in battery, it is a natural backup device. Besides, if you pick the right unit, it will also give you XM weather. (This assumes you don't turn on the weather on your GRT.)
 
Thanks for all of the help guys. Here is what I settled on for my panel:

Dynon D6 for backup instruments
GMA 240 audio panel
GTX 327 transponder
Garmin 496
GRT Horizon I HX EFIS and EIS
TruTrak Digiflight II VSGV
Garmin 430W
Icom A210

Now if I can just cram it all in the 4 I will be all set.

Andy
 
Hah, posting after you made up your mind.

Anyway, I'll add my 2 cents in here. First and foremost, I am a happy customer of BOTH Dynon and TruTrak. That being said, there are a couple of things that Dynon has said in this thread which you should understand are said honestly, but from a marketing perspective. What I'm going to say is my own opinion, but I hope it is fair and presents you with apples-to-apples comparisons.

First, if you were JUST looking at the Dynon as a way to get Autopilot and wanted to compare feature for feature with TruTrak, you should understand that a) assuming you are GOING to have a GRT and b) also assuming that you are GOING to have a 430W, then c) to get the maximum possible use out of your 430W you can have that capability CHEAPER using the TruTrak.

Why? With the Dynon, in order to get vertical guidance for precision WAAS approaches you need ARINC capability, for which you must by the AP74. D10A + AP74 + servos = more than TruTrak Digiflight II VSGV. Now, this combination (single GRT + 430 + TruTrak) does NOT give you a backup attitude indicator (and why TruTrak hasn't made a model of the VSGV with their slick attitude backup I don't know). However, it DOES give you a totally independent attitude system which will fly you through the clouds to safety in the event of EFIS failure; or, you could just buy a used vacuum backup AI.

In the event of EFIS failure the TruTrack mentioned will NOT fly an ILS approach coupled (because it needs the ARINC signal from the GRT, which is derived from the Serial 430 ILS data); however if you install a switch for ARINC data to choose either the 430 or GRT as "source" for the AP then the 430 will happily fly a precision GPS approach in the event of failure of the EFIS. Too, I believe that the 430 offers an HSI page (I know the 480 does, but they are different animals). If that is true, you can use the AP and manually dial in heading and punch in descent rate to keep you squarely centered on an ILS approach.

My second comment was on the audio panel. I got the Sigtronics stereo high-noise 2 place intercom and couldn't be happier. PM me if you need a wiring diagram for attaching the various components - you hook up the audio for the various devices to the music input so they get damped if there is an incoming radio call and so they get boosted sufficiently to hear. You can then set up potentiometers for each input to control volume. I have audio inputs from both the Dynon HS34 and the Garmin 496; works great and I can listen to XM Radio from the Garmin.

PM me if you want a link to a wiring diagram, am at work and can't remember the link.
 
rjtjrt said:
Does anyone know what will happen in this set up above of Frank's, if the 430W quits?
John
Click to expand...

The TruTraks are now all consistent in that they revert to zero bank (rate of turn? still not fully clear on this) in the event of loss of GPS signal.

Check out the TT forum for details.
 
jump4way said:
Thanks for all of the help guys. Here is what I settled on for my panel:

Dynon D6 for backup instruments
GMA 240 audio panel
GTX 327 transponder
Garmin 496
GRT Horizon I HX EFIS and EIS
TruTrak Digiflight II VSGV
Garmin 430W
Icom A210

Now if I can just cram it all in the 4 I will be all set.

Andy
Click to expand...

Final note - I've posted it elsewhere here, but there is a cool "under-documented feature" of the TT. It accepts both ARINC and serial inputs. In your setup, you will want to run the ARINC input off a switch which allows you to set either the 430 or the GRT as the "source" for ARINC steering. However, I would hard-wire the Serial input to the 496. If you have your 430 wired to feed flight plan info to your 496 and the 430 dies, you can simply engage the mode button again on the TT to resume following the flight plan.
 
Blue Mountain Avionics fuel quantity set-up

Can anyone tell me how to set up my BMI EFIS to show fuel quantities using the Van's resistance senders? Havin' a little trouble getting a hold of Greg R. Sure would appreciate some help.
 
Thanks for the tips on the best way to set up the TT with the equipment I have. If anyone has any other tips on the best way to tie these things together to take advantage of all of the capabilities, I would greatly appreciate it.
 
breister said:
With the Dynon, in order to get vertical guidance for precision WAAS approaches you need ARINC capability, for which you must by the AP74. D10A + AP74 + servos = more than TruTrak Digiflight II VSGV.
Click to expand...

A few corrections:

You don't need the AP74 to get ARINC. You need the HS34. The AP74 just makes the AP easier to use, but is not a data converter.

Digiflight II VSGV: $5225
Dynon D10A + 2 servos + HS34: $4350

We're still $900 less, with a "free" EFIS included.

The thing that the IIVSGV can do that the Dynon cannot today is the vertical part of the approach, so they aren't apples to apples comparisons. You could consider the IIVSG to be a better comparison at $4725, which is still more than our solution.
 
My bad and humble apologies to Dynon - I added hastily at work and somehow added an extra $1,000. Sorry!

:eek:

Either solution will work, and as I said I am a happy customer of both vendors.

To my original point, with the AP76 on hold the TT (perhaps also Trio?) is the only solution which will fly a coupled precision GPSS or ILS (through the GRT, or if you buy the more expensive TT) down to minimums. I can't fly an ILS or even LOC at all with my setup because Dynon doesn't have that nice feature GRT has to convert the ILS data to simulate a GPSS approach (hint!). :D

As an aside, I NEVER flew with the glide slope coupled on the ILS anyway (my prior plane had a different TT which WOULD fly the ILS). It tended to hunt too much vertically at a phase of flight when you are too close to both the ground and stall speed for me to be comfortable. Haven't decided yet on GPSS but expect ARINC steering to be smoother. Instead for ILS (if I don't hand-fly it for proficiency) I initially dial in 500fpm descent and adjust up or down. That technique I believe is also available on the Dynon (vertical fpm climb/descent), so it could also probably "fake" either the ILS or GPSS.

The choices are getting tougher every day...
 
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