Need Help with GPS Tso-C146a

[royrtaylorjr]

Hello Dynon: This is my first post and I need help GPS wise. I have the skyview 7" with the Dynon Avionics SV-XPNDR-261. I would like to hook up a certified GPS to it so I have true ADSB out. I have checked out the Freeflight 1201 but the specs are System: TSO-C145a (Class Beta 1). The 261 says it needs TSO-C146A. HELP.
On a side note, My install of the sky view along with the 2 coms, transponder , intercom and adsb receiver was very easy and worked the first time I fired it up. Thanks for your help
Roy Taylor

 

[Dynon]

Where are you seeing a reference to TSO-C146A exclusively? The Freeflight 1201 is one of the explicitly-supported GPSes.

 

[royrtaylorjr]

In looking at the spec sheet from Sarasota avionics, or any of the avionics shops. It is listed as follows:
    Type: Twelve-channel receiver, L1 frequency, C/A code, continuous tracking Nine GPS, 2 WAAS, 1 overhead, satellite capability
    Position Update Rate: Two times per second
    Velocity: 1000 knots, steady-state
    Dynamics: Complies with RTCA/DO-229C, Sec. 2.1.2.5
    Certified Interface: RS-232
    Environmental: DO-160E (A1/C4/D1)

CERTIFICATIONS:

    System: TSO-C145a (Class Beta 1)
    Software: DO-178B, Level C [/b]
This is what was confusing me.

Roy Taylor

 

[royrtaylorjr]

The Transponder spec sheet for the 261 states:
For High Performance Aircraft

Integrated: Made for the SkyView System with control and annuciation appearing on the SkyView Display. The transponder module can be mounted anywhere in the airplane that is convenient.

Traffic: Features TIS Traffic (USA).

Small and Light with Easy Installation: At only 1 pound and 5.6” by 1.8” by 2.4”, the transponder module can fit into the tiniest places and aircraft. A quick release mounting system allows for simple installation and easy removal if needed for service.

Meets USA and Europe ADS-B Out Mandates: Note, full ADS-B Out compliance requires a TSO-C146A GPS (WAAS) to be connected.

Dynon Warranty, Support, and Service: These transponders come with a 3-year Dynon Warranty.

 

[royrtaylorjr]

Is the spec sheet from Sarasota incorrect?

 

[Dynon]

Looks like that's an earlier printing of the sheet that was specific to the capability now. It's incomplete now, though it was correct at the time. There are multiple TSOs that can now be used to satisfy a compliant GPS position requirement. The latest version of that brochure doesn't get too specific as to the specific TSOs that are applicable. But, more importantly, the specific GPS needs to have been approved for use as a GPS source. The good news is that our installation guide has a specific list of compatible GPS products. The Freeflight 1201 is among them.

 

[royrtaylorjr]

Thank you very much. Now I can continue my build. Just did not want to purchase the wrong unit.

Roy Taylor

 

[lolachampcar]

One word of potential caution.  The FAA is requiring antenna to antenna certification which is what is driving the need for an STC or a Field Approval based on an existing STC for a system to be 2020 compliant.

It is unclear how the FAA will handle Experimental installations.  They may turn a blind eye or they may require compliance as they do with a transponder (must be TSO'd although the aircraft is not certified).

In addition to antenna to antenna certification, Dynon uses a different version of the Trig Mode S transponder and Dynon uses its own version of ground/air. Neither of these elements have been shown to be 2020 compliant. So, in addition to the system wide installation acceptance, the FF/Skyview system does not pass the 2020 sniff test from a component level.

Applying this to your (or my) situation, I took Dynon's advice and used their very good and capable GPS sensor so as to allow the FAA more time to sort out Exp and ADSB compliance.  There was no reason to spend $3K for the FF receiver only to have at best equal performance to the Dynon solution and no guarantee of 2020 compliance.

Happy flying.

 

[dynonsupport]

Lola,
The FAA is not requiring antenna to antenna "certification". You don't actually need a TSO for a transponder- you need a transponder that "meets the performance requirements of TSO X". ADS-B is the same, and it's technically legal to put completely uncertified stuff in your experimental- assuming you have data that it meets the performance requirements.

The ADS-B mandate has one weird twist- "all ADS-B OUT installs must be STC'd." Which is impossible in an experimental, which has no TC to start with.

The FAA has actually been pretty clear how they will handle experimentals- they need data showing it "works". One data set they accept is any STC'd combination of a specific transponder and a specific GPS. They will accept other data sets, and Dynon is and has been in discussions with the FAA for years about our setup and demonstrating that it will comply. The Trig transponder and the FF GPS is actually the only combination that has been STC'd so far, so that's the easiest one to show compliance for, and is already accepted by the FAA via their "any STC'd combo rule". On the experimental side, the FAA is more than accepting of the fact that the standard part number for the Trig and the Dynon variant are the same, and thus acceptable. When you last asked you were wondering about putting the Dynon in a type certificated aircraft, and we were warning we have no experience with that and listing possible issues.

We do not use our own version of Ground/AIR. We use the fully certified algorithm in the transponder, which is both compliant and REQUIRED for 2020. The transponder by itself decides ground/air, with no decisions made in SkyView.

As far as we know, have been told, have heard, and have experienced, a Dynon transponder hooked to a FF GPS is fully compliant today and has no caveats or issues with 2020 compliance. If that is worth $3K today is a different issues, but that setup will work.

 

[lolachampcar]

I followed up with Dynon regarding documentation on Pitot/Static performance as an input to the Trigg algorithm.  I also followed up with Trigg on the availability of data or an existing STC using the Trigg algorithm.  No joy on both.

The Perigrin STC I believe you are referencing
http://www.peregrine.aero/STCs.html
Is for the Trigg production part number.  Dynon uses a different connector pin out and thus a different part number.  In addition, the Perigrin STC uses a separate switch for ground/air thus the STC'd or acceptable data for the FAA would use this method of air/ground and the same part number as that listed on the STC.

Look, I'm not trying to make trouble.  At the same time, people telling me things are so then not being able to collect the supporting documentation when I try to make use of that "so" is not helpful.

Dynon, you have a lot more experience than I with the FAA and Experimental aircraft thus you are much more likely to be right.  I'm just cautious.  The FAA will not let you fly with a transponder that does not meet TSO even if you are Experimental.  The FAA has learned the hard way with the helicopters in the Gulf that simply bolting TSO'd bits together is not enough to ensure a functioning system; thus the requirement for an STC or Field Approval based on an STC for certified aircraft.  There is the POSSIBILITY that the FAA may not turn a blind eye to making sure ADSB-out actually WORKS in an Experimental aircraft.  Given that they have seen installations of TSO'd hardware by professional avionics shops in certified aircraft fail to perform, it is not unreasonable to think that they may question us moms and pops bolting the stuff into our planes.

Given that your GPS puck works so well, I thought it best to mention that using the complete Dynon set up today and giving the FAA more time to definitively examine the Experimental/ADSB-Out issue MAY be a wise choice.

Now, if Dynon would like to post or provide some documentation from the FAA that speaks to the acceptability of your part number of the Trigg transponder, your pitot/static input to the Trigg transponder for ground/air determination, the acceptability of the Trigg ground/air algorithm and antenna to antenna installation guidelines that guarantee compliance with the 2020 ADSB-Out mandate then I am all ears and eyes.

 

[rfazio1951]

Looks like that's an earlier printing of the sheet that was specific to the capability now. It's incomplete now, though it was correct at the time. There are multiple TSOs that can now be used to satisfy a compliant GPS position requirement. The latest version of that brochure doesn't get too specific as to the specific TSOs that are applicable. But, more importantly, the specific GPS needs to have been approved for use as a GPS source. The good news is that our installation guide has a specific list of compatible GPS products. The Freeflight 1201 is among them.

I looked through the installation guide and can't find the list of compatible GPS products. Where is it?

 

[rvator51]

Try pages 235, 337, and 338 to see lists.

 

[swatson999]

I don't quite see what the issue is here. Looking at FAA materials, for *experimental* aircraft, you'll need (by 2020) an ADS-B "transmitter" which meets the spec, and a position source (GPS) which meets the spec feeding it. Dynon's XPDR meets TSO appropriately, so pick a certified GPS to your liking (one that can communicate with the XPDR), configure the Dynon system accordingly, and go (after the usual 24-month static/XPDR check, etc.).

As Dynon said, there's no "STC" for E-ABs, so that doesn't enter into the discussion. There's no mention in what I read about antennae at all. What they care about is that your transmitter (here, XPDR) is sending valid data of the required type with the required integrity levels for positional data.

I have a SV system w/ XPDR and a GNS-430W (which I'll connect at annual in a few months, when I have the plane apart and can get to the wiring). I anticipate doing nothing more than that (other than checking the results via the email request to the FAA for confirmation of correct operation).

Here's some info I found, for reference

http://www.faa.gov/nextgen/ga/media/AEA-ADS-B%20Installation.pdf