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Extra 400 upgrade project - call for advice

Thanks Peter. Some comments.

The “paintjob” is just a computer generated pic – the latest iteration of what it should become – the aircraft is not painted yet!
The lower part (dark) is meant to be sanded down to the CF with just a layer of protective lacquer. I am exploring solutions to do this without damaging the composite.

The cockpit photo shows the redesigned instrument panel less the iPad Pro which literally fills the copilot side.
This is because of the 2 “steam” gauges which we needed to reinstall due to the EDM930 lacking adequate sensors.
The iPad runs Garmin Pilot. Sadly I could not use the beautiful (and FAA-certified) flush mount by Guardian Avionics – too wide…
So I had to design my own and 3D print it. It works OK but is not as elegant. You can see the mounting parts if you look closely.

This panel is a “test” version. A V2 iteration will definitely come after some flying experience.
After 4 flights I already noted that I don’t like the position of the engine switches and the fact that the landing gear position lights are hidden by the yoke.
The original design had to host a myriad of instruments which I relentlessly chased out as part of this upgrade.
Now there is premium real estate available that should be used to improve ergonomics and therefore safety.
Notice how the two annunciator devices moved to the upper part under the glare shield. At least this IS final.

LSGG, LFEY, Switzerland

Hello Flyingfish,

to say I am mightily impressed won’t do it justice. You’ve done a fantastic job here, clearly at a price, but it has come out lovely.

Some comments:

Flyingfish wrote:

The only things I dislike are:
1. nose heaviness due to poor W&B design (the plane was obviously designed as a turboprop and V1 got a piston engine that weighs way too much. CG easily slips out of the forward limit and the aft 75% of the CG range is unreachable no matter how much you load the cabin.
2. heavy heaviness: this carbon-fiber plane weighs 1518 Kg empty. Did they mix lead in the resin or what?
3. corresponding handling at take-off and to a lesser extent landing. The nose really wants to go down all the time.
4. STEC55X autopilot. Only climb mode available is VS. This is very dangerous…

To 1: How about adding some counterweight in the tail? With the arm it has it might not need that much weightwise to improve the cg? Question is, whether it’s legally and mechanically possible but I recall someone doing this to a notoriously noseheavy airplane. It only took about 1 or 2 kg in the very rear to get the CG back into a manageable range. This would probably fix No 3 as well.

To 4: I also use the S-Tec 55x as there is nothing better available. Clearly, the VS modes are suboptimum but they are workable. It is not a set – and – forget kind of thing like Level Change or IAS hold, but it will do the job if managed properly. What we have done for the Mooney in that regard is to set up a climb and descent profile in VS which will leave us with a safe margin and at the same time helps engine cooling. We know the airplane will climb between 800 and 600 fpm up to FL100 so we defined a climb rate of 600 fpm to 5000 ft, 500 fpm to 10’000 ft and 300 above that. For descend we have a similar pattern, mostly at 500 fpm which will allow a descent with plenty of TAS but stays reasonably clear of Vne as well as shock cooling the engine. The 2nd bit is the altitude capture: We never leave it in an open climb or descent but whenever it is put in VS, at the same time an altitude gets armed with it. And the 3rd bit is clear: Fly the airplane even (or particularly) when the AP is on. That means watch speed, watch ROC/D.

Clearly, one of the newer digital AP’s with IAS/LVL Change modes are more suitable, but I find we can work very well with the 55X. It is one heck of an improvement over a System 30 or similar AP’s which have no autotrim and no proper VS rate. One bit I do like about the 55X is it’s weird CWS implementation. VFR that one simply is great. It does allow to set a turn rate with the yoke and then regulate VS manually. Not how CWS is supposed to work but great if you get numerous 360ties on approach and an altitude change in between.

Flyingfish wrote:

I don’t like the position of the engine switches and the fact that the landing gear position lights are hidden by the yoke.

Landing Gear I like the way it’s done with the airliners: Up on the panel and the lights up there with it. If that switch and the lights are simple switches with wiring (no mechanical linking) then it’s relatively easy to move them. Otherwise, the lights should be easy in any event. I am thinking of getting a voice warning for the gear too, as the acoustical one is too weak in my plane.

I love the way you did the glareshield, with the AP and the announciators.

Great plane, have yourself a lot of fun with it!

LSZH, Switzerland

@Flyingfish you have a lovely aircraft. I’d envy you if I’d be small enough to fit comfortably…

The lower part (dark) is meant to be sanded down to the CF with just a layer of protective lacquer. I am exploring solutions to do this without damaging the composite.

If the aircraft is in EDKB you might give Aeroconcept in EDKA a call. They have plenty experience in glider / Motorglider painting and are very savvy with FRP structures. Streifeneder would be another great adress for repainting FRP aircraft.

Inside the sky.
EDXE, EDXF, Germany

Mooney_Driver thank you… I am almost embarrassed by your compliments, but they do a lot of good at a time where the aircraft is once again experience weird issues.

Regarding the W&B issue. Thanks for your advice. here is where we stand:

Done tons of simulations of W&B. In fact I started even before we rebuilt the plane because the removal of old avionics would remove 20 Kg, part of which behind the pressure vessel. Somehow I had started with an erroneous initial CG arm in my spreadsheet, which resulted in me believing that all would be ok.
Since finding out about it, we have looked very closely at
1. Adding 4 Kg of lead in the tail cone (this is what it takes to barely shift CG back into the forward limits when loading is only 2 crew no PAX.
It is feasible, no structural issue (tailcone is supported by the strake).
2. Modifying the fuel system and adding a header tank behind the pressure vessel (!) . This would solve 2 problems: it would help CG and it would make the 17 USG (!!) of unusable fuel usable. This is why I did invest the time to assess feasibility. Not feasible on a certified aircraft.
3. Shaving weight off the nose. Replace one of the alternators with a PlanePower unit. This is possible, but the previous owner tried it and failed. I will look at it again, it can’t be rocket science… This would save about 3 Kg.
4. Carrying water filled jerrycans in the baggage compartment. These can be filled or emptied at will and therefore CG can be moved backwards a bit when no PAX. no PAX means little luggage so it would work.
So shifting 3 Kg to the tail cone and adding another 1 Kg to the empty weight looks like a possible solution. It won’t do miracles though. Simulation shows that this plane needs 60 Kg (!!!) less in the nose to be perfectly balanced.
I am very reluctant to further adding to the empty weight. The rule of the game will be: remove weight in the front and use this to “buy” ballast in the tailcone.

I can’t see any engine accessories that could possibly be replaced with lighter ones. The radiators and the intercooler look very heavy but the risk/return ratio is not favorable… Only other idea is to use some aero carpet instead of the plush one that has been installed.

Regarding STEC55x, agree with you. I did try to get a DFC90, but Avidyne’s answer was a final “NIET”…
As a spoiled ex-G1000 boy, I will need to be very very careful…
Your CWS trick is noted.
One positive about the STEC55X autopilot is that it has the Yaw Damper option.

Regarding Landing Gear switches / lights: I also agree with the logic used in airliners.
My problem has been to persuade our avionics chief to move them at all.
In the present development of the V2 panel both the gear and flap subsystems have gained some height bur ar still in the bottom part of the panel.

mh: thanks. I will take a look. My instructor is quite big and he is an Extra 400 owner.

And to round up this post, here is the actual avionics list:
G500 with integrated VS preselect, RDR2000 weather radar control and DME control.
GTN750 primary com/nav
Bidirectional FlightStream 210 interface to iPad Pro and Garmin D2 watch, with backup AHRS/GPS. SynVis, Charts and Checklists on iPad.
GNC255 NavCom 2 (noGPS)
Garmin D2 compass/cabin altitude alerter, emergency GPS.
Ryan 9900 TCAD combined with Garmin GTX345R ADS-B in/out. Consolidated traffic alerts
JPI EDM930 primary engine monitor

We have installed a separate switch to power on the EDM before anything else. Good for the battery and avoids subjecting avionics to voltage swings when starting engine. There is also a separate switch for the G500 to allow a targeted reboot in flight.

Last Edited by Flyingfish at 22 Oct 13:12
LSGG, LFEY, Switzerland

Why do want to power-up the EDM before anything else?

The G500 “reboot switch” is interesting

Shoreham EGKA, United Kingdom


The G500 “reboot switch” is as Peter said, interesting, but on my C/B’s panel, I have 3 circuit breakers concerning the G500:
The GDU, the ADC and the AHRS.

Considering that I don’t have a reboot switch, in case of the G500 failure (or its component), what breaker should I pull first ?
I’ll ask the same question to my maintenance /avionics shop on Monday but that’s good to have several opinions on that…

Au plaisir de te revoir…


Emmanuel! Funny to meet you on-line.

I have no experience with rebooting a G500.
I did reboot the G1000 a couple of times in flight. I did this by switching off the master switch.

Amitiés et à bientôt.

Peter: powering up the EDM first reduces the drain on the battery, allows me to update fuel levels, make a note of times (out of EDM) and start the engine and stabilize voltage before the rest of the avionics come alive and start telling me how they feel.
I found the G1000 and its peripherals very noisy and disturbing during the startup.
From experience so far, this was a good design decision. Very pleasant startup flow.

LSGG, LFEY, Switzerland

More news:

We had to abort the latest flight due to a failed cylinder. (The engine has been rebuilt and the existing cylinders overhauled).
Two of them were ECi, and both failed. There is an FAA AD on these but mine were outside the S/N range of the AD. I will let the FAA know as this AD seems to be justified and maybe a bit on the shy side.

Now grounded again and waiting for a replacement.
Fortunately Alberta Aero Engines have a spare cylinder that can arrive in less than 2 weeks.
We will be able to keep the existing piston. This is important because it preserves the precision balancing work that has been done.

Right now, I am working on a radical redesign of the panel, to keep my spirits up.
I think I’ve taken it a good step further. Will post a drawing asap.

Can someone recommend a source for best quality aviation switches? I intend to move some of them to the panel and would like to take the opportunity to upgrade them all.

LSGG, LFEY, Switzerland

Mooney_Driver wrote:

is to set up a climb and descent profile in VS which will leave us with a safe margin and at the same time helps engine cooling. We know the airplane will climb between 800 and 600 fpm up to FL100 so we defined a climb rate of 600 fpm to 5000 ft, 500 fpm to 10’000 ft

Please let me ask you, have you managed to reprogramme / set up the STEC55X so that it follows these profiles or is this the profile that you choose to fly to maintain airspeed and cooling?
Thanks Q


Regarding pistons, I have been told by my US engine shop that nowadays they come in very closely matched sets, so you can just swap them around. The rest of the moving parts (conrods, crack, pins) do need to be balanced up.

Regarding switches, the best switches I know are French ones made by APEM. Their toggle switches are here and the popular one is here These are sealed, which is right for any environment where there might be moisture, or a fuel leak… You can see these aren’t cheap. They also come in safety-locking versions, etc. A slightly cheaper variant, still high grade but doesn’t feel as good, is this

I have in the past bought a load of these on Ebay, at 1/10 of the price, unused milspec stock from Israel

Honeywell also make milspec switches but they feel less slick than APEM. Here and this is a really nice one which I have used for critical stuff. Honeywell have bought a huge number of companies making switches and transducers…

Shoreham EGKA, United Kingdom
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