Help me upgrade my Decathlon VFR panel

Ed Haywood

En-Route
Joined
Jul 12, 2020
Messages
3,620
Location
Tampa FL
Display Name

Display name:
Big Ed
I'm doing a pre-buy for a Super Decathlon. I plan to do some cross country flying in the Southeast US. I am based in Tampa and will be flying to coastal NC, central GA, and southern MS. VFR only, as neither I nor the plane are IFR capable.

Current avionics is bare bones steam gauges (AS, ALT, VSI, G-meter, MP, RPM, and Turn Coord), NAV COM with CDI, and GTX 335 ADS-B out with GPS antenna. See pic below. I also have a GDL-50 portable ADS-B receiver, mobile devices of various sizes, and a Garmin Pilot subscription.

Vo5NAja.jpg


I would like to improve aircraft safety and practicality for VFR travel, while minimizing cost and not adding weight. Everything must be capable of aerobatics without damage. Interested in thoughts and suggestions from the crowd.

My first thought is to replace the Turn Coord with a G5 AI. That will give me a lot better capability handle inadvertant flight into IMC. I've never flown partial panel on a TC alone, but I can't imagine it is easy. A G5 is a lot of bang for the buck.

Beyond that, VOR NAV is pretty much obsolete. Should I consider replacing the Nav/Com with a built in GPS Nav/Com, like a refurb G430? Or does that not provide any capability that the GDL 50 feeding to a tablet would not do just as well, for a lot cheaper? Does the CDI do me any good or is it dead weight?
 
I agree with Salty.

My guess is that you will end up navigating on your portable. The panel works as is.

Don’t think too hard about backups and inadvertent IFR. Keep it VFR operationally.

In hazy VFR like some of us saw or are seeing due to the dust storm, the TC is easier to fly well than any AI in level flight. It kind of damps out what you don’t need to react to.


Sent from my iPad using Tapatalk Pro
 
You plan to fly VFR. I wouldn't change a thing. I think it is fine just the way it is.
Keep the airplane light; filling it full of crap just adds weight.
There's absolutely zero value installing an IFR panel mount GPS in your plane. For VFR navigation any decent Garmin portable or tablet with a good app will be better, more capable and far less expensive than any older panel mount GPS - by a lot. With that, and a portable radio with headset adaptor, you have 100% back up for comm and nav, independent of the aircraft electrical system.

For inadvertent flight into IMC, use the TC to do a standard rate turn for 60 seconds and get the hell out of there. Better still, don't push your luck.

I bought a 1996 Husky in 2018. It came with a full state-of-the-art-in-1996 panel and radio stack, including of all things a King IFR GPS. Of course back then portable moving map GPS units were just starting to appear, so maybe it made sense to the original purchaser. It doesn't any more for me; I've never turned it on. It's a VFR only airplane for me. I haven't got around to it yet, but I'm going to start ripping that sort of stuff out of it to lighten it up and keep it simple.
 
Yes, I like simple, no need to get carried away with any upgrades right. That said, those Collins Comm and Nav units are fine, until they give up, then probably not worth repair, if you could get them fixed, so I'd have a piggy bank saved for eventual replacement, something like the Garmin 255 might be cheapest, or as suggested above, the 355 GPS/Comm. Or, go minimalist and get the basic Garmin 245 Comm only. But your Collins radios may last many more years, working just fine.
 
OK, seems like the consensus is leave it alone. I can do that. I'll practice turns on the TC until I am confident.

Would it be worth the effort to set up a phone/tablet as an emergency PFD using the AHRS feed from the GDL-50?

Nobody addressed the CDI. Do I need it? Should I sell it?

Can I do anything useful with the GPS WAAS source in the GTX 335, other than be ADS-B compliant?

I will definitely need to add a couple of USB ports.
 
OK, seems like the consensus is leave it alone. I can do that. I'll practice turns on the TC until I am confident.

Would it be worth the effort to set up a phone/tablet as an emergency PFD using the AHRS feed from the GDL-50?

Nobody addressed the CDI. Do I need it? Should I sell it?

Can I do anything useful with the GPS WAAS source in the GTX 335, other than be ADS-B compliant?

I will definitely need to add a couple of USB ports.
Put in a g5 if an AI will make you feel more comfortable. A gnc355 can probably feed the CDI if you go that route.
 
OK, seems like the consensus is leave it alone. I can do that. I'll practice turns on the TC until I am confident.

Would it be worth the effort to set up a phone/tablet as an emergency PFD using the AHRS feed from the GDL-50?

Nobody addressed the CDI. Do I need it? Should I sell it?

Can I do anything useful with the GPS WAAS source in the GTX 335, other than be ADS-B compliant?

I will definitely need to add a couple of USB ports.

Hey folks, we are really slipping here. :eek:
Has there ever been a time before where we advised against spending money on new panel stuff? I mean, what just happened here?:dunno:
Based on past track record we should have advised him to completely junk the panel, go all glass with a G500 TXi paired with a nice GTN 750/650 Xi combo, that fancy Garmin voice command audio panel, digital engine monitor and a new Garmin autopilot. All fitted into a new, custom silkscreened instrument panel. Throwing in a couple of expensive Bose headsets would round things out perfectly, non?
This can't continue...:fingerwag:
People might stop asking for advice. :yikes:

To the specific, serious questions:
  • I'd definitely set up the tablet to receive from the GDL-50. If you already have both, there's no added cost;
  • Presumably the CDI is connected to the Collins Nav. If it is all working fine I would leave it as is. Take it out at some point in the future if you decide to upgrade the radio; but as @Jim Carpenter said above, you might get years of good service from the Collins NavCom. Recognize, presumably "simple" panel upgrades rarely are. They are like house renovations. Once you start opening things up you end up spending more money and time than you expected. All sorts of things can cause issues, starting with old wiring.
  • I don't think you can use the WAAS from the 335 for anything else useful, but @bnt83 or @flyingcheesehead are just two of our resident experts on that sort of thing.
 
Last edited:
Can I do anything useful with the GPS WAAS source in the GTX 335, other than be ADS-B compliant?
IIRC a 335 feeding GPS to a G5+magnetometer will show you TAS and a wind vector.
 
For VFR, it's fine as is. I might add a dual USB charging port for your EFB/GPS tablet that has an internal GPS. And carry a backup EFB/GPS (e.g. smartphone). That should give you redundancy and a neat cockpit. For long XC trips, you don't want your EFB/GPS to run down and die, and while you can carry a powerbank, that's just more stuff rattling around the cockpit, and which also needs to be recharged sometime.

If you want a neater, panel-mounted ADS-B in and out solution, then an upgrade to the transponder would give you bluetooth or wifi weather on your EFB without extra gadgets and wires to the GDL-50 in the cockpit. Depends on how often you are going on long XC trips, and how neat you want the cockpit area.
 
Replace the old nav com with a Garmin GNC355 GPS/Com, and put a G5 in place of the T+B. That will give you some good reliability, and something to get you home in the event of an inadvertent IMC encounter.
 
Spend some time flying with Foreflight or Avare or whatever on your tablet or iPad and then decide if you really need an installed GPS, for me the answer was a resounding "no". I removed the old Narco com and replaced it with a 2" Becker and removed the VOR and replaced it with nothing, saved several pounds.
 
That panel is beautiful. I’d swap out the nav com for a gnc355 and leave everything else alone. Swapping out the turn coord would be ok, but not necessary imo

I completely agree with this. That is if you decide to do anything at all.
 
could go dual GI-275s to keep it looking clean
I love my GI-275. Property the nicest instrument I’ve ever used. If you want to spend money they would look incredible in that panel. I would totally choose them over the G5s.
 
upload_2020-7-20_7-4-54.png

I fly everywhere with a Stratux, a tablet and a handheld. Back up batteries and my smartphone and I'm set to go. Not an IFR solution, but with some practice needle, ball and airspeed work as a get out jail free card.
 
Mmmm, that's one gauge I plan to use frequently. I rarely check while flying; pretty easy to tell G's from physical cues. But the meter is useful when practicing for contests to make sure you are pulling hard enough on entry. The natural tendency is to under-pull.

Ah, didn't realize that you were going to compete with it. Then keeping the G-meter makes sense.
 
I vote for a helmet mounted HUD.

Realistically, I vote the panel is fine as is and agree to keep the old collins unit until it dies on you. A comfortable parachute and a little scrubbing to make everything shiny is probably a better investment.

What about aileron spades? I haven't flown a Decathalon, but in a Citabria the difference was very noticeable.
 
Spend some time flying with Foreflight or Avare or whatever on your tablet or iPad...

Or iPhone or equivalent. Big enough to display a sectional with a magenta line to follow, GS, ETA at destination and so forth. Giving up a lot of screen real estate compared to even an iPad Mini, but mounted high enough and close enough to the pilot, more than enough info for VFR flying. Or a Garmin Aera 660 or similar for a dedicated solution.

And I agree with others to just fly the plane for a while as is. Upgrade as things break, or as you see a real need. Or just on a whim. No right answer that suits everyone.
 
VFR day? I’d remove the turn coordinator, VSI, navcom and CDI, and install a com radio. Use a tablet or sectional for navigation and enjoy.
 
All good answers. Thanks very much for all the insight and opinions.

I was considering a G5 upgrade mainly because the seller is an A&P who likes to upgrade planes.

But I concur with the comments saying not to mess with it. I'll get some dual hood time to make sure I'm comfortable flying on the TC.

Also concur that my 10" tablet with Garmin Pilot and GDL-50 input for WAAS GPS, AHRS, and ADS-B IN is probably as good or better than panel options costing 10 times as much.
 
If the thing doesn't have lights then you definitely shouldn't touch the panel at all. I was thinking you may be flying at night and the G5/GNC355 might be nice, but with no lights, don't do it.
 
It does have lights. I won't be making a habit of night trips, but late afternoon return trips have a way of turning into night trips for the last hour.
 
Personally, I would want an AI if there was a chance I'd be flying at night, but that's just me.
 
if you must, you can do a GTN650, G5, and a JPI engine monitor. The decathlon I flew just had the engine monitor and it helped. I do know of a fully IFR decathlon my flown by a CFI i use for currency. But for simple fun, just fly baby fly, no need for the whizbang.
 
Personally, I would want an AI if there was a chance I'd be flying at night, but that's just me.

Well, that's what originally motivated me to start this thread.

Bottom line, I am buying the plane I WANT instead of the plane I NEED. So now I have to rationalize some work-arounds.

I need a decent XC plane for 500-600 mile business trips with 1-2 passengers and light bags. I also need to finally get my instrument rating after 30 years of scud running. But when I searched for what was available for my budget, I did not like what I saw. Everything in my range has issues, and I lack the knowledge to evaluate the risk of those issues.

Then I stumbled across the plane I really wanted all along, just 90 miles away. Or the plane found me. It has issues too, but I understand those issues, so I can make an informed decision on risk and value. It also helps that the price is well below my budget.

But I still need to make work trips. I can travel by myself, and I do have total flexibility to change my schedule for weather delays, but I still need to do XC.

The Super D will do XC ... but not very well. Instead of filing IFR, getting up high and doing 5 hour legs at 140kt, I'm going to be bumping along under the clouds in VFR and making fuel stops every 3 hours at 120kt. I'm ok with that, and I've even convinced myself it will be fun barnstorming across the southeast in a T&F taildragger. But I do need to consider safety, and an AI does seem like a benefical upgrade.

After thinking about it, I do not want to hack up the panel unnecessarily to put in a G5. I also do not need all the redundant data that the G5, GI 275, and AV-30 display, since I prefer analog dial gauges for airspeed and altitude when flying acro. However, the gauge hole digital horizons are interesting. Maybe something like an RCA2610?

2610-3.jpg
 
Last edited:
After thinking about it, I do not want to hack up the panel unnecessarily to put in a G5.

Why would you need to "hack up the panel?" The G5 will fit in a standard instrument hole. You only need to do extra work if you want to flush mount it. Quite frankly, it looks just fine without flush mounting and they work great. I have two, both an AI and HSI, and they fit in the existing holes and look just fine.
 
What about putting an AV-20-S in the empty 2" hole the left side? Only $895 certified???

11-17557a.jpg
 
It does have lights. I won't be making a habit of night trips, but late afternoon return trips have a way of turning into night trips for the last hour.
[/QUOTE]

Personally, I would want an AI if there was a chance I'd be flying at night, but that's just me.

What about putting an AV-20-S in the empty 2" hole the left side? Only $895 certified???

11-17557a.jpg

I agree with @Salty

If "the last hour" might be at night, and it's not certain to be over a well lit area (city, urban landscape, interstate, etc) then I would definitely install an AI and make sure I have adequate panel lighting (post lights or backlit instruments).

But for that I still think a G5 is expensive overkill. An electric horizon like the RC Allen or AV 20 would seem perfectly adequate and economical for those few occasions where you might be landing after dusk.
 
The RCA costs more than the G5. Probably cheaper to install, since the only connections are power and ground. I do like the clean look of the RCA. But is the TC required equipment, and is it replaceable by an AI?
 
OK, I'm going to buck the trend here and suggest a GI-275 AI replacing the VSI, especially with possible night flight. My rationale:

* It's not too expensive. Around $5000 installed, I think.
* It's clean, as it's a round gauge that would fit in the round panel.
* It includes a VSI and the VSI hole has a cutout for the knob that the TC hole does not.
* It neatly fills in the other thing missing in the panel: A DG.
* It will keep working in the event of an electrical failure, whereas the TC won't. It'll even be lit.
* You can configure what you want on the display. If you don't like fancy, you can turn it off.
* It doesn't care about attitude or G's like the spinning gyro in the TC does.

The pretty but cluttered SVT background in all the pics is actually an optional add-on. Most of the clutter on the screen isn't even present without a GPS attached anyway. One thing I'll admit I don't know is where the heading comes from. That may also not be available without GPS, as I don't think it comes with a magnetometer. Not sure if the 335 can provide that source. G5 isn't a bad choice, either, but it's a wash on cost as there is a magnetometer to install. And it isn't round. And the display is crude. For reference, I have a pair of G5 in my 172, so I have experience with that. (Installed before the GI-275 was available.)
 
I am looking at this wrong. This is an acro bird that does XC, not an XC bird that does acro. The panel is optimized for the primary use case, probably by people who know a lot more about acro than I do.

I do not use gauges much when I fly acro, except for Speed and Altitude check before each maneuver. I prefer outside visual cues such as a sighting gauge against the physical horizon. However, straight and level recovery is a part of contest grading. The VSI (and maybe the TC) could be useful to confirm S&L and fine tune control inputs to get the highest score. For example, on an Immelman, airspeed is close to MCA when performing the half roll at the top. If you recover with nose-level attitude you will have sink rate, and that will downgrade your score. Checking the VSI right as you stop the roll could help refine your presentation, especially if you don't have a coach.

So based on all that, an AV-20-S in the 2 1/4" gauge hole on the left side would be the least disruptive way to increase XC safety, and also quite cost effective. That, and some hood practice on the TC and VSI.
 
Last edited:
Cool, thanks for the mock up! Here's what I'm thinking of initially. Already have the 10" tablet and the GDL 50. If the big tablet bumps my knees, a mini-tablet would fit well horizontally in that space. RAM yoke mount should attach solidly to the tube frame.

mock panel - Copy.png
 
Last edited:
Back
Top