Questions - ADSB-Out as it is today and tomorrow

[lolachampcar]

Using a complete Skyview system... My first question is what is the FAA report going to look like when I request compliance performance feedback from the "9-AWA-AFS-300-ADSB-AvionicsCheck@faa.gov" email?  How does the non-certified nature of the Dynon GPS receiver come across / affect the report back from the FAA?

For the future-
Given that the Trig transponder is used, will moving to something like the FF 1201 as a direct to transponder GPS source allow for a passing compliance test from the FAA?  What is needed to tell the Trig unit to use the direct connected GPS source instead of that provided by Skyview (and do you need to set up the input format)?

I'm working on using Trig/FF 1201 in a certified aircraft under a field approval which is what is generating all these questions.  I'd like to try out the whole FAA compliance feedback deal using my nicely functional Skyview system to get some experience but would really like to know if there are any gotchas before I head off down the path.

Thanks,
Bill

 

[RVDan]

When you email for the report tell them that the gps is uncertified and they will let you know if it is correct for an uncertified GPS.

 

[GalinHdz]

Setting it up for 2020 compliance will depend on whether your transponder is an actual TRIG unit or a Dynon SV-XPONDER-261 module, made by TRIG.

If it is an actual TRIG unit the GPS source is connected directly to pin #5 of the transponder module. http://www.trig-avionics.com/library/TT2x-00560-00-AM.pdf
If it is a Dynon SV-XPONDER-261 the GPS source is connected, via a 1.2K ohm resistor, directly to pin #3 of the transponder module. http://www.dynonavionics.com/downlo...iew_System_Installation_Guide-Rev_R_v11.0.pdf

Then go to the configuration section of the transponder module and set it up to use the certified GPS source. I hope this helps.

 

[lolachampcar]

I understand the physical connection differences. I was more fishing for information about how the FAA views experimental aircraft, how the mandate affects we experimental guys/gals and if we can use the FAA's in flight quality control system to verify our current and post 2020 installs. I can not help but think Dynon has a master plan and, like they always do, have thought through the matter in detail.

Hopefully that work includes masking a TSO'd firmware to their GPS engine of choice then having it TSO'd The puck rocks and is really what we should be doing for certified GPS for GA ADSB-out.

 

[Dynon]

In short:

- If you use SkyView's GPS for ADS-B, your report will have a bunch of red boxes for some of the parameters that report the integrity of your position fix. The first page will also note that you've got some issues that affect your eventual mandate compliance.
- The FAA's OK with experimentals having non-compliant installations because the mandate doesn't go into effect until 2020. Jan 1, 2020, they care a lot more
- There's a lot of technical data in those reports, and there are even things in there that we need some clarity on. But if you're using SkyView's position source (ie, not a compliant source like a GTN or 430W), you don't even really need to pull the report. If you're getting ADS-B FULL(SkyView 10.1 and below) or ADS-B OK (SkyView v11 or later), you're waking up the system and getting full traffic and weather back, which is what you care about immediately. If you're ONLY ever getting PARTIAL or NO RADAR, something's up with your configuration, whether it's wires or settings or antenna.
- While we don't have a master plan for 2020, I like to point out that there is 5.5 years until the mandate takes effect. 5.5 years ago, we hadn't even released SkyView at all. In other words, it's an eternity away in avionics terms. By 2018 you'll probably just install a chip in your head and talk to the ADS-B towers yourself. Your brain may need to be 2020-compliant though

 

[hoyden]

Received my report yesterday. SIL and SDA are zero with percent fails of 100%. Other failure categories have very low % failure; <1%.

 

[lolachampcar]

Dynon
Thanks for the info and hoyden thanks for the detail.  Any chance you can post the report you received back?

Also, does anyone know how the FAA views certified aircraft with failing position integrity?  I ask here as I know I will get nothing but blank stares if I ask at the FSDO

Lastly, I know we're are a long way off but then there is A LOT of work that needs to be done in that 5.5 years.  In addition, there is a lot of FUD going around WRT ADSB so having clear open discussion with people like the guys at Dynon who are living it from a technical standpoint (and do not have an axe to grind unlike some other vendors) is a breath of fresh air.

Dynon, any interest at all in masking a TSO'd firmware to your GPS puck???

 

[RVDan]

I have done several STC's for certified aircraft and use the same report to validate the installation.  Certified installations should come back compliant if that is what they are certified for. 

In the interim until 2020 the data is being used to indicate how well installations are going and to help validate the air ground datalink.  I have had them pull up an aircraft I am working and reviewed each data hit.  You can see data until you go below coverage.

After 2020 i suspect a failing aircraft will be mailed a notice, sort of like RVSM is handled.

 

[Dynon]

Certified installations are only allowed with all TSO'd bits and an STC for the installation, so they're inherently 2020 compliant.

 

[lolachampcar]

If one were to use the SV Trig transponder (along with the Skyview of course) in combination with the FF 1201 GPS receiver for a TSO'd or compliant ADSB-Out solution, could the 1201 position data be used in parallel by Skyview? Would you just "Y" the 232 data to both the txp and the SV systems?

 

[GalinHdz]

Any chance you can post the report you received back?

FWIW: I have a DYNON SkyView system with a Garmin G430W as the GPS position source. This is the report I got back from the FAA. Fully 2020 compliant:

http://puertoricoflyer.com/Files/N819PR - ADSB Report.pdf

This is a document the FAA sends trying to explain what the report means:

http://www.puertoricoflyer.com/Files/N819PR - ADSB Report Explanation.pdf

 

[dynonsupport]

SkyView cannot use the FF data format. Not that there is a big reason to- it doesn't gain you anything except redundancy. It's a slower GPS (1Hz) than the Dynon GPS.

 

[lolachampcar]

$200 for a Dynon GPS receiver is not much so I can live with the financial impact of that statement but you must see the irony in saying do not use the $2500 (plus expensive TSO'd antenna) as your position source because it is not as good as ours.

Is it really true that the TSO adds zero value? Is it better to report a less accurate position more often? Is Dynon's product an order of magnitude less reliable? Just curious.

I'll check the manual but I assume you wire the FF into the Txp and leave the Dynon puck a direct wire to SV.

 

[dynonsupport]

We see no irony in saying more expensive devices are less useful than Dynon's stuff. Isn't that what Dynon was founded on?

There are two main uses of GPS position in a SkyView system:

1) The SkyView display which uses this for the moving map, synvis, and other calculations
2) The transponder, which uses this for ADS-B out.

For #1, a certified GPS isn't as good for the simple reason that it outputs data at 1Hz, not 5Hz. This means your screen can only update once per second, so it will be more jumpy. Yes, things like the 430 or GTN products have 5Hz GPS sensors internally, but they only send that data out at 1Hz. Even with a certified GPS on board, we prefer the Dynon GPS when it's working because we see the use of the Certified GPS as a negative, not even neutral much less positive.

On top of this, if SkyView's screen has certified position, it doesn't make it any more legal for IFR navigation.

Now, we do support connections of certified GPS units to SkyView, it's just not the Freeflight units. Not many people are equipping with those in experimental planes right now. It tends to be that you either fly IFR and thus have a full IFR navigator like a GTN/GNS, or you are VFR and are waiting until 2019 and expect a TSO'd GPS to be a lot cheaper than $2500 by then. We could write support for the FF data format, and might if there is enough interest in it as a backup GPS source.

The Dynon GPS puck is extraordinarily reliable and accurate. The TSO doesn't define any of that. You can legally make a TSO'd product that breaks every other hour. All the TSO really defines is that it knows it has broken and doesn't output bad data. There's a very real chance that our $200 GPS receiver is more accurate than any TSO'd receiver. The TSO also defines only a minimum performance level that is often far from commercially good enough- all of our RF products seriously exceed the TSO in many ways since a modern, good product blows the TSO out of the water.

For #2, you need a certified position source to be 2020 compliant. That can be a FF unit or Garmin IFR navigator today. More in the future I'm sure. If you don't care about 2020 compliance today (and it gets you nothing to do so) then we can use the uncertified GPS in SkyView to source this. ADS-B data is always at 1Hz, so the data rate doesn't get you anything here, and your SkyView position and transponder position can come from totally different sources.

 

[lolachampcar]

Thank you! And yes, that is exactly why I buy Dynon equipment.

 

[William_Ince]

Thank you!  And yes, that is exactly why I buy Dynon equipment.

And that is why I also bought Dynon SkyView displays and GPS/AP.

I am waiting to install ADS-B out though.
Just my opinion, but I think within the next few years, the equipment will get even better and hopefully, the prices will come down.

Right now, I think ADS-B out is still too expensive.

 

[cmgolden]

a certified GPS isn't as good for the simple reason that it outputs data at 1Hz, not 5Hz. This means your screen can only update once per second, so it will be more jumpy. Yes, things like the 430 or GTN products have 5Hz GPS sensors internally, but they only send that data out at 1Hz.

If I change the Flight Plan source on the Map page to an ARINC/430W to see my IFR-GPS flight plan route on the map, will the map page then only update at 1 hz? 

If so, is there a way to benefit from the improved 5 hz position updates of the Dynon GPS puck, while still displaying the 430 flight plan on the map (other than re-entering the flight plan in the Dynon for the map page)?

P.S. Sorry to stray from the post's original subject.

 

[dynonsupport]

Using the 430's flight plan does not decrease the update rate of the rest of the SkyView system. Everything still runs at 5Hz.

 

[mike_newall]

If you were going to use an output from the Skyview as position for the SV-XPNDR, which pin is it coming out of the Skyview from ?

The input to the transponder shows pin 3, but where are we getting a supply from ?

 

[swatson999]

If you were going to use an output from the Skyview as position for the SV-XPNDR, which pin is it coming out of the Skyview from ?

The input to the transponder shows pin 3, but where are we getting a supply from ?

I believe it's via the already-connected serial lines to/from the XPDR. You don't connect the puck directly to the XPDR.

This is what I have currently, and it works just fine (just have been too lazy to crawl under my dash and connect my 430W to the XPDR... ).