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Experimentals won't require TSO'd ADS-B equipment

DrillBit said:
My understanding is a devilish detail remains: A TSO'd txpndr + TSO'd, IFR-legal GPS is still not a legal ADS-B system. The whole system, including the wires, where the antenna is, in a one-of-a-kind EAB plane, has to meet the TSO performance requirements.

Before the FAA's clarification, the ADS-B regs seemingly required a (supplemental) type cert to prove full compliance with the ADS-B 2020 mandate. Since EABs by definition have no type certs, no Bravo, Charlie, or Mode C veil flying allowed.

Now, an (S)TC is not required, just a demonstration your unique, one-of-a-kind EAB aircraft's ADS-B system meets TSO's performance requirements. Apparently, that's still such a complex, expensive thing to accomplish, few EAB owners could do it.

I think this also means you can buy the exact same parts for a certified plane's ADS-B system (even an all-in-one txpndr-GPS-encoder-antenna box as other posters have suggested), have them installed in your EAB by shop with all the qualifications to work on certified ships, and pay the certified prices for the whole shebang...and it wouldn't be recognized by the FAA as a mandate-meeting ADS-B set-up, unless it was tested as a system according to the complex, expensive methods that earned a certified plane its (S)TC.

If I'm not wrong, the Dynon txpndr can continue to be hooked up to Dynon's GPS (or any other GPS device for that matter) after 2020. But the the bits and bytes in the extended squitting will declare "I am not a 2020-compliant ADS-B out broadcaster!!!". You'll still be able to wake up ground stations and get receive ADS-B in traffic, etc. But stray 1 yard inside a Mode C veil and the FAA will probably tell the NTSB's administrative law judge that by gum, they're 100% positive the GPS position was accurate, so the pilot certificate action is justified. <Insert Law & Order Cha-Chunk Sound here>
Click to expand...

I believe Dynon has stated on their forum that they have been working with the FAA for quite a while on this, and that it is expected that they will demonstrate that their XPDR connected to the usual suspects of WAAS-enabled GPS (430W, GTN, etc.) are compliant, that they'll provide documentation of that and that the FAA has indicated (or said) that such is expected to suffice for E-ABs. You can search their forum for their exact wording.

This makes the GPS-XPDR system analogous to a XPDR-only system in E-ABs (where there is no such thing as an STC) for installation by E-AB owners/builders to meet the appropriate FARs.

Personally, I think there's an awful lot of hand-wringing over this, along with a pretty fair amount of misinformation (thanks to EAA's Editor-in-Chief, among others).
 
That's why I've wired up pin 6 (IIRC) on my Dynon transponder's 25-pin D-shell: GPS serial in. Coiled up the wire and secured it for the future....

I hope a 5 Hz GPS receiver (with WAAS etc.) will suffice--one doesn't need a big-G navigator to feed the txpndr lat-long, heading, and velocity. (Not planning on IFR capability for N748PK at this time.)
 
Kurt,
There are only two FARs you need to follow: 91.225 and 91.227. Neither states you need a TSO or installation approval. AC 20-165 and other documents which guide installation approval for TC'd aircraft don't apply to EAB.

What the FAR does require is that you meet some performance level, and some of this performance is the system design assurance, which is where the issue between the GPS and ADS-B device comes into play.

This isn't all that different than all the other things you do as an EAB builder or operator. You have a lot of FARs to comply with, and as the operator, it's you that has to verify you are in compliance. It's just as illegal to fly a plane out of conditional inspection as it is to not have a compliant ADS-B system when you need one, and it's up to you to decide to buy non-TSO'd lights for your plane and then fly at night, where specific lighting performance is required by the FAR and your operating limitations.

Now, today, it is hard for a EAB builder to know the system they have in the plane is compliant, because without design documentation, it's a really technical thing to do. If you start with two TSO'd devices, AC 20-165 actually sets up a pretty easy test flight to do that the FAA will help you with. If you want non-TSO'd devices, then you need more data, since you can't rely on the TSO to back you up in many areas.

The FAA, EAA, and industry is aware of this issue where an STC documents compliance for a TC'd airplane, but there's no official path of documentation for an EAB. Everyone is working on this, and just like we saw a clarification from the FAA this week on some ADS-B language, the expectation is that they will also issue guidance for EAB compliance very soon.

Did they kind of mess up and do we wish they had this guidance as part of the rule back in 2010? Sure. Are they also going to fix this oversight 5 years before the rule takes effect and make sure that 20% of the GA fleet can keep flying? Yes. Not a single person I have talked to in the FAA's NextGen group wants anything but a clear, simple path for EAB operators to know they are compliant.

--Ian
Dynon Avionics
 
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N941WR said:
Jordan1976 said:
...This isn't true for ADS-B. You can't get around the ADS-B requirement by having a generator that isn't spun by the engine. You must have no electrical system at all to fly under the Mode C veil and not have ADS-B.
Click to expand...

I think the way the FAA looks at is that "engine-driven electrical" system is the key. Even with the wind generator, I would be exempt.

That said, I am checking and will report back.
Click to expand...
I heard back from my contact at the Charlotte FSDO and here was his reply:
CLT FSDO said:
Bill;
At this point, which could always change, if the aircraft does NOT have an engine driven power system, then it will be exempt just like the transponder.
But of course, like I said, it could change.
...
Click to expand...
 
N941WR said:
I heard back from my contact at the Charlotte FSDO and here was his reply:
Click to expand...

Not to continue to beat this horse, but a response from a single person at a random FSDO = ZILCH...as far as actual "legal" positioning and interpretation from the FAA goes. There are numerous examples in history of folks relying on responses from a singular person at a random FSDO only to be violated later (and having it stick).

As the old story goes, if you ask 50 different FSDO folks the same question, you'll get 60 different answers. Some folks hunt until they find the answer they like, but it still doesn't really mean much of anything in regards to the law. So it goes with many 3 letter gubm't agencies. Rely on advice from an IRS employee and try to use that in Tax Court as a defense? Do a web search and see how that turned out for many folks. :)

I'm not taking sides on the actual subject answer you received, just pointing out that response from a singular FAA person is almost useless from a legal perspective. Sometimes you're best off not asking the question to begin with, because then they have to answer (and if they don't know the answer, what you get might not be the answer you want)!

Just my 2 cents as usual.

Cheers,
Stein
 
SteinAir said:
Not to continue to beat this horse, but a response from a single person at a random FSDO = ZILCH...as far as actual "legal" positioning and interpretation from the FAA goes. There are numerous examples in history of folks relying on responses from a singular person at a random FSDO only to be violated later (and having it stick).

As the old story goes, if you ask 50 different FSDO folks the same question, you'll get 60 different answers. Some folks hunt until they find the answer they like, but it still doesn't really mean much of anything in regards to the law. So it goes with many 3 letter gubm't agencies. Rely on advice from an IRS employee and try to use that in Tax Court as a defense? Do a web search and see how that turned out for many folks. :)

I'm not taking sides on the actual subject answer you received, just pointing out that response from a singular FAA person is almost useless from a legal perspective. Sometimes you're best off not asking the question to begin with, because then they have to answer (and if they don't know the answer, what you get might not be the answer you want)!

Just my 2 cents as usual.

Cheers,
Stein
Click to expand...
Which is exactly why I worded it the way I did. However, this follows the same rules they have been using for transponders, so it will probably stand up.
 
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Another option on the market:

http://navworx.com/products-ADS600-EXP.php

The ADS600-EXP? is a remote mounted Universal Access Transceiver (UAT).

  • Meets performance requirements of TSO-C154c
  • Transmits SDA = 2, SIL = 2
  • Provides Traffic and Weather via Wifi or RS-232
  • Internal Wifi
  • Connects to optional TransMonSPE for control panel and altitude encoder input
  • read more

$699
 
Amazing. This changes everything, especially if you can connect a SIL 3 GPS.
 
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Jordan1976 said:
Scroll,
For someone in your situation, which is a person with a Dynon transponder installed, what you need is a GPS on board that is compliant with the rules. This unfortunately is not the one integrated into SkyView, due to the requirement that it "meet the TSO" which is a very complex thing to demonstrate.

So, by 2020, you will need a new GPS, but that's it. Dynon's recommendation for someone in your situation is to wait. You still have years to comply, and industry has years to make a set of solutions you can choose from. As more affordable solutions come up, Dynon will be there to support them and give guidance on what you need to be sure you are legal.

--Ian
Click to expand...

Ian,
Thanks, good Sir, that helps. :D
 
The FAA is actively attempting to shutdown GA..

How can they expect $10k worth of compliance on a $60k aircraft?

I guess I need to start looking into this..
 
Question

If you elect to not install a compliant ADS-B system, the only places you can't fly are in class B and inside the mode C veil.

Is that correct?
 
twisted-wrench said:
Question

If you elect to not install a compliant ADS-B system, the only places you can't fly are in class B and inside the mode C veil.

Is that correct?
Click to expand...

No it's not. You could not fly anywhere that a Mode C transponder is currently required. That would be:
Not inside class B or the mode C veil around the central airport.
Not inside class C, nor above it.
Not above 10,000' MSL except in rare cases where it is class G, or within 2500' of the ground.
 
We?ve been answering a lot of questions from customers emailing and calling since the FAA made the rule clarification on Monday. The short answer (which has already been discussed in detail on this thread) is that the rule clarification does not change anything regarding performance requirements.

The design assurance and performance requirements for the position source haven?t changed, and even though our GTX 23 ES is a fully rule compliant TSO?d Mode S transponder that meets all the 2020 requirements when connected to a GNS 4XXW/5XXW or GTN 6XX/7XX IFR GPS navigator, the G3X system isn?t rule compliant when used with the VFR GPS built into the GDU 37X and GDU 4XX displays.

There continues to be a lot of talk in the media about the FAA possibly relaxing ADS-B requirements and this recent minor rule change has done nothing but fuel the fire. Garmin has been closely involved in discussions with the FAA and we don?t see any reason to believe the FAA will relax the requirements at this point. Garmin will continue to work with industry partners and lobby for GA and experimental aviation. But we would not advise customers to plan on a non-compliant installation being a good long term solution.

Thanks,
Brian
 
the navworkx solution has gps but you still need a certain type of transponder to go with it... not quite a "complete" solution...
 
It does indeed have a built in GPS. Not a TSO'd GPS but they seem to be interpreting the new rule to mean that experimentals won't need a TSO'd GPS position source, just a GPS source that performs to TSO'd specs.
 
edneff said:
the navworkx solution has gps but you still need a certain type of transponder to go with it... not quite a "complete" solution...
Click to expand...

They offer a transponder interface gizmo that sniffs the squawk code and altitude from the RF output of your existing mode C transponder or if you have a GTX-327 or 330 then it can connect directly.
 
Peterk said:
So why can NavWorks offer a compliant system for thousands less than anyone else? What are we missing here?
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I personally think they are making marketing claims that they will never be able to back up.

No way I would buy into their current interpretation of the rules.

The bottom line is that to claim you meet the performance standard means that eventually the FAA is going to want you to prove it. How are you going to do that? Just saying "Because the manufacturer says it does." ain't gonna cut it when they have not went through the trouble/time/expense to prove it for themselves.....
 
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And a digital transponder like my GTX327 or their $150 unit to capture altitude and squawk off your non digital transponder. I say pretty complete for $699
 
brad walton said:
And a digital transponder like my GTX327 or their $150 unit to capture altitude and squawk off your non digital transponder. I say pretty complete for $699
Click to expand...

The big question remaining is their interpretation of the new rule from the FAA on whether the non TSO GPS in it will still be legal to use after 2020.
 
Here is what it says on the NaxWorx web site.

The ADS600-EXP? is a remote mounted Universal Access Transceiver (UAT).

Meets performance requirements of TSO-C154c
Transmits SDA = 2, SIL = 3
Provides Traffic and Weather via Wifi or RS-232
Internal Wifi
Connects to optional TransMonSPE for control panel and altitude encoder input

Note:
The ADS600-EXP meets the ADS-B Final Rule Technical Amendment, dated 2/9/2015, affecting 14 CFR 91.225 (b)(1)(ii) which permits ADS-B OUT in the NAS with devices that meet the performance requirements of TSO-C154c
 
As far as "proving" the EXP box meets the performance spec: Since Navworx already has a TSO'd GPS they may be thinking of "qual by sim" for the EXP box. If the EXP box happens to use the same GPS chipset and/or the same circuit card assembly as the TSO'd box it may be just a paperwork exercise with the Feds. This approach is very common with military avionics boxes.
GZ
 
Tram said:
The FAA is actively attempting to shutdown GA..

How can they expect $10k worth of compliance on a $60k aircraft?

I guess I need to start looking into this..
Click to expand...

To keep this in perspective from the FAA point of view. When the EPA first required catalytic converters on cars, it cost $200 for the converter. GM was building an entire V8 engine w/carb for $200 at that time!

Don't count on "reasoning" as a valid argument.
 
GPS Specs are different

As far as "proving" the EXP box meets the performance spec: Since Navworx already has a TSO'd GPS they may be thinking of "qual by sim" for the EXP box. If the EXP box happens to use the same GPS chipset and/or the same circuit card assembly as the TSO'd box it may be just a paperwork exercise with the Feds. This approach is very common with military avionics boxes.
GZ
Click to expand...

Navworx specs for the -600BG TSO GPS (-143dBm tracking; -137dBm acquisition) are different from the -EXP (-156dBm tracking; -144dBm acquisition).

No idea if these numbers are significant.

Regards,

Merrill
 
mdevans9 said:
Navworx specs for the -600BG TSO GPS (-143dBm tracking; -137dBm acquisition) are different from the -EXP (-156dBm tracking; -144dBm acquisition).

No idea if these numbers are significant.

Regards,

Merrill
Click to expand...

If I follow this correctly, they are claiming that the EXP GPS is almost an order of magnitude more sensitive than the TSO GPS (by 13 and 7 dB). Not sure if significant, but certainly a "better" spec claim for the EXP than the TSO.

I don't generally play with RF above 30 MHz, but these numbers are probably 50 dB better than the noise floor of any receiver I've ever built! :eek: 156 dB below a milliwatt is almost not even there.

Hoping this is the first of several competing offerings in this price range that will enable E-AB aircraft compliance by 2020.

-Stormy
 
g3xpert said:
The design assurance and performance requirements for the position source haven?t changed, and even though our GTX 23 ES is a fully rule compliant TSO?d Mode S transponder that meets all the 2020 requirements when connected to a GNS 4XXW/5XXW or GTN 6XX/7XX IFR GPS navigator, the G3X system isn?t rule compliant when used with the VFR GPS built into the GDU 37X and GDU 4XX displays.



Thanks,
Brian
Click to expand...

Without revealing any proprietary information, would the Garmin team mind explaining the difference between a TSO'ed and non-TSO'ed unit. Is it different hardware internally or the same hardware but a different level of design documentation and testing required to meet the TSO standard.

I find it hard to believe beyond the consumer level GPS chipset there are really that many alternatives for components that support RAIM etc. So do all the units really have the same chipsets regardless of TSO status.

Another example of this is the GTR200 radio (great unit thanks Garmin), is it really that different inside from it's TSO'ed big brother the GTR225.

Robert
 
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