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Help me decide on an upgrade path

Malibuflyer wrote:

Looks to me like their way to say “Of course it works but legally we are not allowed to recommend it because it is obviously not allowed in certified aircraft…”

They were quite aware of how SC051c is written, so I don’t think that’s what they meant at all.

Again, SC051c allows such a connection if the FLARM equipment manufacturer says that it’s ok. You don’t need the approval of the nav box manufacturer.

ESKC (Uppsala/Sundbro), Sweden

Peter wrote:

Standard avonics shop position is: not on the STC = cannot be connected. Various threads – example.

Possibly. I’m lucky to not use a standard avionics shop, then.

OTOH my avionics guy says that an STC is better than a Standard Change because with an STC, all the documentation has already been written in the STC IM. For an SC, he must develop the documentation himself. I’ve found him using obscure STCs or EASA minor change approvals when an SC would work perfectly well. (E.g. for installing a NAVCOM.) Not always, though.

ESKC (Uppsala/Sundbro), Sweden

People who really know the Minor process can do amazing stuff. Under both EASA and FAA. But very few do, hence the “can’t do this without an STC” stuff.

I don’t know the details but for “pure monitoring” it should not be restricted. Under FAA, you can install more or less anything for “monitoring” provided it is TSOd (that gives you automatic approval for installation, because it demonstrates environmental etc compliance) and that is a Minor Alteration. So for example you can install a Sandel EHSI on the RHS, displaying all the usual stuff, from NAV/GPS1/GPS2/ADF/whatever and bring every imaginable signal into it (DME(s) also) and it is all on a Minor, just a logbook entry. Provided it cannot drive the autopilot

In this case we are talking about a traffic display, so why should that be different? But as I say I don’t know the EASA logic.

On a non-certified plane, none of this should matter, however.

BTW what is wrong with the TruTrak? Possibly there is no pitch trim, so altitude hold (ALT), VS, etc, become a bit “interesting”. It also can’t fly a heading, only a GPS track. But while the GFC500 can fly an ILS (very relevant to Europe) it can’t do it without GPS (it disconnects the GS if it loses GPS, reportedly).

Administrator
Shoreham EGKA, United Kingdom

Airborne_Again wrote:

Data bus/data connectivity between the FLARM device and other equipment which is:
• ETSO-authorised (or the equivalent); or
• required by the TCDS, AFM or POH; or
• required by other applicable requirements such as those for operations and airspace,
is not allowed unless the FLARM device is explicitly listed by its manufacturer as compatible equipment to which the other equipment can be connected

Airborne_Again wrote:

Again, SC051c allows such a connection if the FLARM equipment manufacturer says that it’s ok.

Interesting! I read the CS-tan differently than you. In my opinion, the “its manufacturer” refers not to the manufacturer of the FLARM device, but to the manufacturer of the “other device” it is connected to.
So a FLARM device must only be connected to a Garmin Navigator if Garmin lists this FLARM device as compatible equipment. Doesn’t matter what the FLARM manufacturer says.

Germany

So a FLARM device must only be connected to a Garmin Navigator if Garmin lists this FLARM device as compatible equipment.

That’s the traditional industry view.

Doesn’t matter what the FLARM manufacturer says.

True, unless the mfg has an STC.

However, the OP has an uncertified aircraft, no? So all of this is moot. It’s like installing a GTN750 in a Trabant; no STC support but 100% legal

The uncertified aircraft installation requirement is for TSOd avionics where they transmit e.g. radios, transponders, DME, etc. That is also how the FAA does it. The UK LAA does some other weird stuff.

Administrator
Shoreham EGKA, United Kingdom

Malibuflyer wrote:

In my opinion, the “its manufacturer” refers not to the manufacturer of the FLARM device, but to the manufacturer of the “other device” it is connected to.

I don’t see how the sentence can possibly be interpreted that way. If you have the expectation that it “should” refer to the manufacturer of the “other device”, then sure, you could just say that the wording was sloppy and that’s what is meant, but linguistically it can only refer to the manufacturer of the FLARM device.

Last Edited by Airborne_Again at 26 Jan 18:33
ESKC (Uppsala/Sundbro), Sweden

Hmm, so based on the discussion, it’s the “safer bet” to just go with the AT-1 by Air Avionics. Price is similar to the PowerFlarm Fusion and at first glance I don’t see any advantage of the PowerFlarm Fusion over the AT-1.

Peter wrote:

BTW what is wrong with the TruTrak? Possibly there is no pitch trim, so altitude hold (ALT), VS, etc, become a bit “interesting”. It also can’t fly a heading, only a GPS track. But while the GFC500 can fly an ILS (very relevant to Europe) it can’t do it without GPS (it disconnects the GS if it loses GPS, reportedly).

The TruTrak is great on paper. It’s just that neither the original builder nor the people I talked to so far could get it to work the way it’s intended. Currently, it flies TRK mode, IAS climb to target alt, VS descent to target alt and ALT hold. It somehow receives GPS data which it needs for TRK mode. But so far no one could get it to work in GPSS, GPSV, HDG, NAV mode. It also doesn’t take the altitude bug from the G600 and I am not sure if it is capable of this even in theory. I haven’t tried ILS yet and not sure if it would work without GPS (which would make it superior to the GFC500 in that regard).

It is inferior to the GFC in two respects:
1) user interface is not intuitive
2) it doesn’t fly as smoothly. it is not 100% stable in straight and level flight, it’s always a bit “chasing”. And when e.g. changing altitudes it is quite abrupt. It feels as if the servos are more “crude” than with the Garmin system (I know the GFC700 very well) and cannot physically be as precise.

I do have electric pitch trim, but it is not coupled with the TruTrak. It gives a visual indication when it wants me to trim however.

All that being said, the more I think about it, the more I am inclined to give the TruTrak another shot:
1) Will get the TruTrak sent to USA to get the latest firmware on it
2) Will update the G600 and GNS530W onto the latest firmwares
3) Check if the wiring is all done correctly between the Garmins and the TruTrak, then also double check the software settings (e.g. ARINC 429)
4) Install the AT-1

I still need to figure out if there is an additional benefit of replacing the GTX-328 Mode S transponder (I guess ATC would be more happy to have ADS-B data, but for collision avoidance maybe the AT-1 is enough?). If I replace it with e GTX345 I have ADS-B In/Out, it integrates traffic into the Garmins, but I am missing FLARM. So the AT-1 + GTX-328 seems better still.

I’m also wondering what the use of the GNC-250XL GPS/COM is. Why did the builder put it there? The GPS functions are made redundant by the 530 / g600. and the COM doesn’t support 8.33MHz, so I basically use it exclusively as a 121.5 standby COM2.

i’m surprised no-one brought up ADL Golze weather yet. It seems a ADL150B would be great (the ADL190 and ADL200 have ADS-B Traffic but that is already taken care of by the AT-1). The ADL150B should integrate with the G600, which would be awesome.

Switzerland

You cannot have a HDG mode without a heading source, which in GA avionics is normally a fluxgate magnetometer.

In fact GA autopilots cannot fly NAV (GPS or VOR/LOC) without a heading source, because they fly HDG as the primary target and then use the GPS/VOR/LOC deviation to adjust that. Same as they fly PIT as the primary target and use the ALT/GS deviation to adjust that. It is difficult to have a stable control loop which runs LOC or NAV as the primary, or ALT as the primary, because you get a delayed feedback on these. In fact barometric feedback is especially crappy.

Administrator
Shoreham EGKA, United Kingdom

Interesting. so it is all connected: the fact that I don’t have HDG function automatically means I cannot fly NAV. The Garmins do have heading information though, so it seems a fixable communication error.

I just learned that since I am flying an experimental, I don’t need a GFC 500 but instead can go with a G5X + GMC507, which changes the cost equation somewhat. Choices over choices :)

Switzerland

Peter wrote:

It is difficult to have a stable control loop which runs LOC or NAV as the primary, or ALT as the primary, because you get a delayed feedback on these. In fact barometric feedback is especially crappy.

Interestingly, the KAP140 holds altitude very well, even though it’s not pitch based. But I suppose it has accelerometers to complement the barometric feedback.

ESKC (Uppsala/Sundbro), Sweden
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