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DR400 (steam) avionics upgrade

My club just acquired a 197x DR 400-180 Régent.
It’s equipped with an IFR panel (steam gauges, see attached picture).
Apart from VFR flights, we also plan to use this DR400 for ‘fair weather IFR training’.
To prepare for 8.33kHz we want to change the VHF, and then some voices raised asking for a GPS/Com/Nav system.
We’ve limited knowledge or experience of modern avionics and would like to propose the most cost effective and elegant way of doing this upgrade.
I also fly on a GNS530+430 equipped TB20, so I know this equipment, and I heard it could be found ‘second hand’, but it’s not the only solution I imagine.

What would you recommend ?

Thanks in advance for your answers.

LFLY, France

I assume it is F-Reg.
It looks like a lot of work
Steam gauges are perfectly alright.

The ADF takes a lot of space and can be removed.
You won’t fit 530+430 combination into the panel.
But a second hand double GNS430 would be ok.
A new audio panel.

You can go and put a GTN650 or 2 in.
Is it worth to invest a load of money?

Last Edited by mdoerr at 24 Nov 16:41
EGBE - Coventry, United Kingdom

Don’t exactly know the rules for IFR aircraft equipment in France, particularly with reference to BRNAV and Annex10.

You say it’s only for IR training, so you shouldn’t overdo it.
Since you have to get at least one 8.33 radio anyway (6000€ installed?), you might consider a GNS430, which (used) go for little money now. That will also give you a decent Nav radio, GPS approach capability and should cost between 10000 and 15000 depending on a few factors. Jesse might be able to help.

Mainz (EDFZ), Germany

I’m going down the same road at the moment with a DR400-180 of the same vintage, the GTN750 is to big to enable all the other kit to fit in the panel so the GTN650 is the way to go, it will control a remote transponder so that will save some space.

The ADF fitted needs to go in the scrap bin and the remote DME indicator is good if it is connected to a KN63…… If not decide if you need a DME. Both the GTN650 or the Garmin 8.33 NAV/com will control the DME.

For controlling the audio the Garmin audio panel is good or the PS engineering 8000BT is better.

Is it worth doing ?

You won’t get your money back if you sell the aircraft but it will increase the usage and should make money for your flying club.

For my personal DR400 it is about getting the aircraft the way I want it and enjoying it for the next 20 years, the DR400 is the only fixed pitch fixed gear aircraft that will perform my required mission of non stop to the south of France so for me it is worth it……but I don’t see me
recovering the cost if I sell the aircraft next week !

You may also find that the electrical cables that Robin installed when the aircraft was built have reached the end of the road and while the panel is out these may require replacing with cable that is not of the original motor car quality, the cables on my aircraft would have been a fire hazard in another five years !

Last Edited by A_and_C at 24 Nov 20:15

Hallo MDoerr u. Boscoromantico,
Vielen Dank führ deine Antwort.
Here is more background information.
1) First, the flying club is not a business like an airline, so pleasure is part of decisions (I’m only a member).
2) New audio panel was fitted last week: Garmin GMA340
3) ADF: I thought in EASA-land an ADF was mandatory for IFR. Am I correct ?
4) GPS rationale: since we need only 1 single 8.33 VHF to comply with new channel spacing rules, we’d like to install only one GPS/Nav/Com system (GNS430W, GTNxxx or equivalent).
Wouldn’t rules for IFR in France be the same as in any EASA member country ?
Would it be OK to perform GPS approaches with one single GNS or GTN ?
If not, do you think we could retrofit 2 GNS/GTN boxes in this already quite packed panel ?

Last Edited by Nestor at 24 Nov 20:21
LFLY, France

Wouldn’t rules for IFR in France be the same as in any EASA member country ?

BRNAV (RNAV5) is mandatory for all IFR in Europe.

Till 2-3 years ago it was mandatory only FL095 and above and maybe only in some countries.

“But any old GPS” installation can be BRNAV approved. My KLN94 is BRNAV. A GNS430 (old non-W version) can even be PRNAV (RNAV1) approved! So this is not an issue, but you need to find an installer who understands the paperwork and who will give you the right AFMS (flight manual supplement) which authorises BRNAV at least.

IMHO nobody should spend any significant money on avionics today unless they get PRNAV because that is still a dark cloud on the horizon.

But maybe not for IR training because most instrument training is done in VMC and not on Eurocontrol IFR flight plans.

As regards other equipment, AFAIK currently this remains under national control (e.g. whether you need 1×8.33 or 2×8.33 radio, etc).

Would it be OK to perform GPS approaches with one single GNS or GTN ?

Of course. But only the GTN (or 430*W*) will support LPV.

Shoreham EGKA, United Kingdom

Hi A and C,
As I said earlier, we’re like you: we fly for pleasure, not for business.
In fact we already retrofitted another “basic VFR” DR400-160 to complete Garmin 500 + GTN650.
This other DR400 is a DR400-180 Régent which was already IFR, so we thought we could do something “in between”, taking the excuse of the 8.33kHz mandatory upgrade to add GPS capability.
Idea would be to add one GPS/Com/Nav box, maybe two if using GPS for IFR mandates a redundant GPS.

LFLY, France

The avionics requirements are airspace requirements, it can therefore differ from country to country. If you have enough panel space I would recommend you to keep the ADF, to meet those requirements.

Normally I would suggest you to download the Garmin GTN simulator for I-Pad (there is also one for PC, but this is not representative). In the settings you can choose if you want to simulate the GTN-650 or GTN-750. That way you can review and discuss during a club meeting for example if the equipment does what you want.
In this case the DR400-180 is not on the EASA AML STC for the Garmin GTN products. Making it quite expensive to install.

The double GNS is only possible if you can use an existing approval, as it is currently classified as a major change for new approvals. This make this modification quite expensive as you will need to hire a design organisation to make the design change. A single GNS can be installed as a minor change.

I guess to keep it affordable you would be limited to install either a single GNS-430 or GNS-530.


Would it be OK to perform GPS approaches with one single GNS or GTN ?

Yes sure. The only downside of 1 GPS is that you always need to be able to reach an alternate where you can land with the remaining equipment should the GPS pack up, and it should have suitable weather to get in.

Very often there’s a big airport with several ILS fairly close, so this doesn’t seem to be very limiting, I think.

LSZK, Switzerland

Thanks Jesse and Tomjnx,
With all the above posts, I now understand why the other IFR-DR400 in our club, a DR400-160 with Garmin 500, is equipped with a single GTN650 (and not dual).
I concur, we must keep the King KR85 ADF, although the one already installed is very big (look at the picture).
More questions now:

1) Where would you fit a GNS430 or GTN650 on this panel ?
The only available space would be the removal of 1 King KY97A VHF, which is not sufficient.
Does this mean we must consider replacing the King KR85 ADF, which is bulky, by a smaller one ?
Or maybe we could move the KR21 Marker Beacon Receiver to a position above the Audio Panel, giving two standard spaces to instal a GNS430 or GTN650 ?

2) Do you think the existing 2 x NARCO NV122D Vor/Loc/Glide indicators could work with a GNS430 or GTN650 ?

Last Edited by Nestor at 24 Nov 21:20
LFLY, France
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