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Minimalistic panel upgrade for "inexpensive" aircraft

Looking at, for example Planecheck, you see a lot of aircraft in the price range around 20 – 30 000 € without basic future proof panels, ie without mode S transponder and 8.33 kHz radios. I guess that the reason they are in this price range is that the market for planes needing upgrades equal to or over the purchase price to keep them flying is almost non existant.

But, let’s say you got a good deal on one of these aircraft. What’s the most minimalistic and inexpensive panel you would put in, if the following criteria were to be met to fullest extent possible? What would be your first sacrifice in order to bring costs down?

  • B-RNAV capability (LPV if possible)
  • Mode S
  • 8.33 kHz radios (at least one)
  • possibly getting rid of vacuumdriven instruments
  • IFR capable (not just compliant)
  • used equipment ok, doesn’t have to be new
  • autopilot, preferably 2-axis with altitude preselect

Carry-on equipment would include an Ipad (with back-up) coupled to a GDL 39 3D and ADL 140 running Garmin Pilot and the Golze app for amongst other things back-up attitude, synthetic vision and in-flight weather (radar, IR and sferics). Intended mission would be IFR touring and traveling.

Last Edited by Axe at 20 Sep 21:32
Axe
ESOK

For many aircraft you don’t need to upgrade too much, but it’s still going to easily add €10000+ to your costs, even going conservatively.

A used Garmin GNS 430 and suitable CDI, if the aircraft doesn’t already have one, would cover two of your first three points, assuming you can live without LPV. Yes, they are old but these boxes are remarkable value for money. If you want LPV, then go for a GNS 430W instead, but at higher cost – and then you should also consider a GTN 650.

If you need a Mode-S transponder, you might not see many on the used market. The Trig TT-31 is excellent value for money, though personally I prefer the numbered buttons of the Garmin GTX330. I believe the Bendix King KT74 is really a rebadged Trig unit with Garmin-style numbered buttons. If you’re going for the latest technology, then consider the Garmin GTX 335 (or 345) for ADS-B Out (and In).

If you want to minimise costs, then you don’t need to get rid of the vacuum instruments, assuming that they work, of course.

It would be very useful to have an autopilot, but it’s not essential. IFR without an autopilot is entirely possible, but especially in IMC it is definitely more tiring. If you’re going to do serious IFR touring, then an autopilot is probably essential. I suspect many aircraft in the price range you mentioned either won’t have one at all, or it will be INOP.

EGTT, The London FIR

Excellent point regarding the autopilot. Would never consider an airplane for IFR touring without at least a 1-axis autopilot coupled to the heading bug, night and day when it comes to minimizing task saturation. So I’ll add that to the list above:

  • Autopliot, preferably 2-axis with altitude preselect
Axe
ESOK

Axe, the budget of €30k is actually enough to buy an aircraft already equipped with almost everything you want. My example: Grumman Tiger with Garmin GNS430 + DME + ADF for navigation, Garmin GTX330 mode S transponder and Century II 1-axis autopilot with tracking, bought for €26000 six years ago.

LKBU near Prague, Czech Republic

Ditto to everything above.
I’ve heard it said that you should buy a plane the way you want it, rather than buy and upgrade.
The reason for this is that the seller is liable to lose a lot of value for the installed avionics on the sale.
Also, not always the case, but older AC that have better avionics were typically better cared for all the way around (owner willing to spend to keep it in good shape).

However, if I were to buy an oldie and upgrade, my list would go something like this:

1) XPDR = 3-5k (also consider an Avidyne AXP340, which is a drop-in KT76A replacement and an OEM’d Trig with a custom-designed UI)
2) NAV/COM = 7-10k min (Installation will hurt and make this a 10k+ job) I’d go with a 430W/IFD440 or better (regular 430 is already obsolete)
3) ELT = 1.5k installed – you can go a little cheaper, but why?
4) EDM = 5k+ installed
5) Autopilot = 8k+ (if you’re touring, this is pretty much standard equipment… )
6) LED Landing Light = 0.5k+ (keep your battery for your avionics, you’ll need it in case of propulsion loss at night)
7) Redesigned Panel = 1k+ (if you’re replacing circle steam gauges with square electronics, something will have to change…)
8) Audio Panel = 2-4k

Minimum is about 5k and you aren’t getting a lot for that. Just coming up to speed. (XPDR/COM/ELT)
Better is about 12k, which gets you the above plus a decent NAV system
Optimum is about 20-30k. That should make flying “easy” and fairly stress-free.

No expert, but recently did a bit of research for upgrades.

Last Edited by AF at 20 Sep 22:24

Ultranomad wrote:

Axe, the budget of €30k is actually enough to buy an aircraft already equipped with almost everything you want. My example: Grumman Tiger with Garmin GNS430 + DME + ADF for navigation, Garmin GTX330 mode S transponder and Century II 1-axis autopilot with tracking, bought for €26000 six years ago.

Amazing deal. Well played. I’m floored and impressed!

I concur, but those deals are far and few between. For the rest of us it is probably up to either finding a plane upgraded to sell, ie done at the lowest cost possible, or one that needs refurbishment. I like the latter because if you are planning to keep the plane for a while it might be worth a little extra to get it the way you wan’t.

My take resembles the ones above almost identically. Which in itself is a telling sign of how limited the market is. I’d probably do this:

  • GNS 430 (at the current pace the ILS doesn’t seem to disappear so no need for LPV yet)
  • Trig TT31

Then play the waiting game for a decent retrofit autopilot like the TruTrak or Trio. Or maybe even the Dynon Skyview HDX. Should any of these ever become available for anything other than a C172 or P28A in EASA-land.

On a side note, what in the panel could be replaced by a Garmin G5 and a Sandel SN3500?

Axe
ESOK

Finners wrote:

The Trig TT-31 is excellent value for money, though personally I prefer the numbered buttons of the Garmin GTX330.

There are plenty of mode-s Garmin GTX330 on ebay at this time. A normal price should be USD1000-1500. Many people in the US are going for a GTX345 for being ADS-B in-out compliant. This would be the least expensive option.

Axe wrote:

On a side note, what in the panel could be replaced by a Garmin G5 and a Sandel SN3500?

I would go for 2 times a Garmin G5. You have full redundancy and replaces your AI and DI. Also will be able to drive your future G500 autopilot and interface with the GNS430. The other option indeed is to wait for the full Dynon Skyview integrated solution, but this is also not very cheap.

Ukraine

Axe,

there are plenty such airframes out there, not all are on planecheck however. The real good ones usually never get there but are around on the local airfields where they usually don’t fly much and people have been toying with the idea of selling but never really got the guts to take the decision.

Avionic upgrades are always expensive but one can try to minimize them by looking out for planes which have the VERY expensive stuff already. First of all that is the autopilot. A plane with a working autopilot (even if it’s a legacy one) will have more possibilities, particularly if an Aspen EFD is in the calculation. The Aspen has a GPSS interface which allows GPSS via the heading mode with almost all legacy AP’s which can take a HDG signal from an old gyro. It also has an altitude alerter which can be upgraded to an arming system if you own an S-Tec 2 axis AP. So I’d always try to find a plane which already has an AP.

GNS430’s are available widely today and the WAAS versions are also becoming available. A normal 14/28V 430 can be upgraded to WAAS quite easily. If there is a 430 installed already (or a 530) then that is a bonus as long as it’s not a 28V only one, as that one is no longer supported by Garmin, but you can upgrade it to WAAS if it breaks. Of course a GNS will automatically mean you have 8.33.

Transponder: No brainer: Trigg. If there is an old KT76A it is a question of pulling the old one out and putting the new one in. Works. If not, changing it is not a big issue and they are relatively cheap.

What I did to my airplane was to upgrade the 430 to W and install an Aspen and an S-Tec 55X AP. That was costly but now the plane is very nice to fly and has all functions I wanted. That is another thing you might consider when buying a plane with an old panel: you can make it your own and put in what YOU really want, not what your predecessor wanted.

For VFR, it is even easier. You need Mode S (again the Trigg is cheap and good) and eventually 8.33. There are 8.33 radios around which are also not too expensive so there is really no need to install a GNS or GTN. Far easier to either fly with a tablett PC or to get a VFR GPS like the Garmin 695 or similar which provide more than enough for VFR travel.

LSZH, Switzerland

Mooney_Driver wrote:

What I did to my airplane was to upgrade the 430 to W

How much did you pay for that and where did you have it done?
I’ve got a 430, but they’ve raised the price of the upgrade so much that it seems more worthwhile to upgrade to an IFD440 instead…

Any advice/thoughts?

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