ADSB visibility with non certified GPS

On Thursday, September 28, 2017 at 11:20:23 AM UTC-7, Tom BravoMike wrote:
How does this offer fit into our discussion? For experimental gliders, and from the price point of view?

http://grtavionics.com/home/ads-b-so...ionix-echouat/

It does not fit anywhere. As discussed on r.a.s. many times in the past.

It is a UAT Out device. Invisible to PowerFLARM, invisible to TCAS.

And most importantly, It's not a transponder.... which the bulk of this conversation should be focused on.

On Thursday, September 28, 2017 at 11:35:19 AM UTC-7, jfitch wrote:
On Thursday, September 28, 2017 at 10:33:56 AM UTC-7, Darryl Ramm wrote:
On Thursday, September 28, 2017 at 9:12:56 AM UTC-7, jfitch wrote:
On Wednesday, September 27, 2017 at 10:24:48 AM UTC-7, son_of_flubber wrote:
I asked Trig support this question:

"Will a TT21 + TN72 transmit a non-zero quality indicator?"

Here is their reply:

"The TT21 is fully certified to the latest ADS-B Out cert TSO C166b – so it can output all the required data. It is true that if you wish to meet ADS-B Out compliance FAR 91.227, you should have a higher power TT22. However, there is no way for the radar to tell if you’re using a TT21 or TT22. Inspection of your aircraft would be the only way to tell. As such I believe a number of experimental pilots have opted to ignore the requirement , but of course I cannot recommend this as it would be in violation of FAR 91.227 – the requirements for 2020 compliance.

The TN72 offers both a SIL =1 output, and also a SIL = 3 output.. So this means that you can meet the FAA compliance check using your TN72 plus TT21. https://adsbperformance.faa.gov/PAPRRequest.aspx

If you so choose, you can opt to have your TT21 upgraded to a TT22. For more information on this please contact our US service centre below;

Trig Avionics Technical Support
9400 East 34th Street North
Wichita
KS 67226
United States

Tel: Toll Free 800 821 1212
Tel: +1 316 630 0101
Email:
Web: www.mcico.com
"

The response to my inquiry with is:

"The cost to update the TT21 to the TT22 is $950.00. Turn around time is 3-4 days in house."

That is some very useful information right there. Two questions:

Does the receiver (FAA) have any way to tell more information about the GPS source? If it is transmitting an SIL of 3 (required for carriage requirements), other than physical inspection can a receiver discriminate between a 70 and a 72?

There is no GPS Source vendor ID. No Mode-S transponder or UAT Out vendor ID, no serial numbers, no encryption signature, etc. allowed for in the design of ADS-B. The lack of signature is a much more serious shortcoming IMNSHO that any of the others. ADS-B Out systems do transmit SIL, NIC and NAC GPS quality parameters and interestingly CC (capability code) that describe if the aircraft has 1090ES In and/or UAT In.

What does Powerflarm do with a glider having both ADSB out and Flarm? Does it deambiguize?

Yes it deduplicates them, based in aircraft ICAO address. Presumably PowerFLARM gives priority to the FLARM signal but somebody like Dave would have to confirm that.

I believe FLARM also deduplicates Mode S PCAS alerts based on ICAO ID. It can't do that to Mode C PCAS alerts because there is no ICAO address broadcast on Mode C.

So hypothetically, an install of a TT21/TN72 in a certified glider is undetectable as such without a physical ground inspection? It looks to the receiver identical to a TT22/TN70 installation? (Ignoring here the regulatory consequences of such an inspection).

Yes.

---

There also things here I am going to follow up on about my understanding of install regulations in certified gliders and the situation with TABS. I'd like to have that clearly clarified by the FAA.

On 09/28/2017 12:50 PM, Darryl Ramm wrote:
On Thursday, September 28, 2017 at 11:20:23 AM UTC-7, Tom BravoMike wrote:
How does this offer fit into our discussion? For experimental gliders, and from the price point of view?

http://grtavionics.com/home/ads-b-so...ionix-echouat/

It does not fit anywhere. As discussed on r.a.s. many times in the past.

It is a UAT Out device. Invisible to PowerFLARM, invisible to TCAS.

And most importantly, It's not a transponder.... which the bulk of this conversation should be focused on.


Seems a little harsh. It clearly states it's for use in conjunction
with a Mode C transponder. That will work fine with TCAS, and will give
PCAS type warnings on PF. If Tom already has Mode C, then it would be a
low cost option for making him more visible, and adding dual-band ADS-B
in at the same time.

-Dave

On Thursday, September 28, 2017 at 3:59:36 PM UTC-5, kinsell wrote:
On 09/28/2017 12:50 PM, Darryl Ramm wrote:
On Thursday, September 28, 2017 at 11:20:23 AM UTC-7, Tom BravoMike wrote:
How does this offer fit into our discussion? For experimental gliders, and from the price point of view?

http://grtavionics.com/home/ads-b-so...ionix-echouat/

It does not fit anywhere. As discussed on r.a.s. many times in the past..

It is a UAT Out device. Invisible to PowerFLARM, invisible to TCAS.

And most importantly, It's not a transponder.... which the bulk of this conversation should be focused on.


Seems a little harsh. It clearly states it's for use in conjunction
with a Mode C transponder. That will work fine with TCAS, and will give
PCAS type warnings on PF. If Tom already has Mode C, then it would be a
low cost option for making him more visible, and adding dual-band ADS-B
in at the same time.

-Dave

That's exactly my case. I have the Microair T2000SFL and am willing to move toward ADS-B, without spending more than necessary, with the expected benefit of seeing and being seen electronically. At moments it sounds in the discussion here like one-sided visibility solves the problem: "you have the transponder - you are safe because they will see and fly around you". I would like to be seen by all practical means, and see possibly all traffic, so that I can react on my part, too.

On Thursday, September 28, 2017 at 2:32:12 PM UTC-7, Tom BravoMike wrote:
On Thursday, September 28, 2017 at 3:59:36 PM UTC-5, kinsell wrote:
On 09/28/2017 12:50 PM, Darryl Ramm wrote:
On Thursday, September 28, 2017 at 11:20:23 AM UTC-7, Tom BravoMike wrote:
How does this offer fit into our discussion? For experimental gliders, and from the price point of view?

http://grtavionics.com/home/ads-b-so...ionix-echouat/

It does not fit anywhere. As discussed on r.a.s. many times in the past.

It is a UAT Out device. Invisible to PowerFLARM, invisible to TCAS.

And most importantly, It's not a transponder.... which the bulk of this conversation should be focused on.


Seems a little harsh. It clearly states it's for use in conjunction
with a Mode C transponder. That will work fine with TCAS, and will give
PCAS type warnings on PF. If Tom already has Mode C, then it would be a
low cost option for making him more visible, and adding dual-band ADS-B
in at the same time.

-Dave

That's exactly my case. I have the Microair T2000SFL and am willing to move toward ADS-B, without spending more than necessary, with the expected benefit of seeing and being seen electronically. At moments it sounds in the discussion here like one-sided visibility solves the problem: "you have the transponder - you are safe because they will see and fly around you". I would like to be seen by all practical means, and see possibly all traffic, so that I can react on my part, too.

Tom

Sorry, yes the product info clearly states for use with a Mode C, but I did not want to assume that use was implied in your question. Your question just said experiential glider, and I want to be very clear what it will or will not do.

When it comes to airlines and fast jets visibility to them, and ATC, should always be the first goal, visibility of them is also useful of course, and in other situations visibility of other traffic become more important (e.g. you can respond more effectively to avoid slower the traffic, that traffic is less likely to have TCAS, or any traffic display system etc.)

You already have a transponder, which is great. Next question is do you have a PowerFLARM? I am guessing not, but I'll touch in that below.

First, please don't adopt UAT Out in the glider community, it is a poor choice given so many gliders have PowerFLARM and will not see your UAT position data, they will see your transponder via PCAS as long as it is being interrogated, but of course that's much less precise that FLARM or ADS-B. If you do have PowerFLARM already, OK that traffic will see you by FLARM. But 1090ES Out is still a better choice, including because it provides longer range visbility of you to all the PowerFLARM users.

Because of compatibility with PowerFLARM if you have a Mode C transponder in a glider and want to go to ADS-B Out then the much better path is to upgrade your transponder to Mode S and a suitable GPS source. Please sell or give your current Mode C transponders to another pilot or club to use.

When considering the cost of things, remember older Mode C transponder will eventually die and need to be replaced, and so why not just replace it now with a Mode S?

And that device asked about does have a dual-link UAT and 1090ES receiver which is great, but there is no way to get that data to display on common soaring flight computers, PDAs etc. You could add a dedicated display for that.

If you do want to add PowerFLARM in future that is likely to be a mess with no way to dedupe traffic from your UAT and ADS-B In system. Again, discussed a lot on r.a.s. and more info can be found by searching, I hope that problem gets solved over time.

If you do want a complete separate dual-link ADS-B In system then products like the Status S2, Statux, and uAvionix Scout, and more are options. (I don't have any personal reports of Scout use). A dual-link ADS-B In system will receive all line of sight 1090ES and UAT Out traffic. It will not receive TIS-B ground service (ADS-B data based on SSR radar) without a compliant ADS-B out system to make your aircraft an ADS-B client. (the UAT system you ask about would do that, but again your ADS-B Out won't ever be seen by PowerFLARM).

GRT avionics and uAvionix targets experimental aircraft, and your question was clearly about experimental. And no surprise that the UAT device is non-TSO. But I do get frustrated with both vendors here not providing really clear specs on their website of what the RTCA and TSO standards the product actually meet. The leading bold "meets 2020 claim" is only true for experimental aircraft, that should be even clearer.

Darryl,

Thank you for your extensive explanation. It basically confirms what I have understood so far about the system. Funny as it may sound, and contrary to the points you bring up, I seem to be even more convinced now that the relatively cheaper UAT system is the way to go.

1. I do have a Stratux with AHRS (on a second display, the first being XCSoar)and I'm subscribed to the iFlyGPS which has great screens with ADS-B traffic, plus includes photos of outlanding airfields with beautifully marked runways). I haven't tried it out extensively yet, but the little I have flown showed quite good visibility of the towers soon after launching.

2. I don't have PowerFlarm and don't think will go for it (but never say never). My doubt arises from the fact that it is so expensive while being limited to the soaring world. IMO, a better way to go is: forget FLARM, let everybody be equipped with ADS-B and let software apps calculate the collision avoidance with other gliders in soaring (BTW, I don't know what the probing/transmission frequency is for both systems). You state "so many gliders have PowerFLARM" - do we actually know how many? Percentagewise? So many problems/discussions on r.a.s. about Flarm upgrades, lack of range, antennas placing, poor customer service, interference issues etc. are not very encouraging, to be honest.

3. Why do so many sources say: You fly above 18,000 ft? Go for 1090. You fly below? Go for 978 ? See in that respect e.g.

https://www.garmin.com/en-US/blog/av...on-is-for-you/

but disregard the specific equipment suggested.

4. For me, the key term is: ALL PARTICIPANTS. Broadcast your information, receive as much information as you can (both with the help of the ground service centers/towers), use/tinker with what you get, adjusted to what you need for safety and competition by proper software onboard. Common, massive use of ADS-B will drive prices down.

5. I fully agree with your advice to upgrade to Mode S, which would open new options. The depth of the pocket will have the final say.


On Thursday, September 28, 2017 at 5:24:01 PM UTC-5, Darryl Ramm wrote:
On Thursday, September 28, 2017 at 2:32:12 PM UTC-7, Tom BravoMike wrote:
On Thursday, September 28, 2017 at 3:59:36 PM UTC-5, kinsell wrote:
On 09/28/2017 12:50 PM, Darryl Ramm wrote:
On Thursday, September 28, 2017 at 11:20:23 AM UTC-7, Tom BravoMike wrote:
How does this offer fit into our discussion? For experimental gliders, and from the price point of view?

http://grtavionics.com/home/ads-b-so...ionix-echouat/

It does not fit anywhere. As discussed on r.a.s. many times in the past.

It is a UAT Out device. Invisible to PowerFLARM, invisible to TCAS.

And most importantly, It's not a transponder.... which the bulk of this conversation should be focused on.


Seems a little harsh. It clearly states it's for use in conjunction
with a Mode C transponder. That will work fine with TCAS, and will give
PCAS type warnings on PF. If Tom already has Mode C, then it would be a
low cost option for making him more visible, and adding dual-band ADS-B
in at the same time.

-Dave

That's exactly my case. I have the Microair T2000SFL and am willing to move toward ADS-B, without spending more than necessary, with the expected benefit of seeing and being seen electronically. At moments it sounds in the discussion here like one-sided visibility solves the problem: "you have the transponder - you are safe because they will see and fly around you". I would like to be seen by all practical means, and see possibly all traffic, so that I can react on my part, too.

Tom

Sorry, yes the product info clearly states for use with a Mode C, but I did not want to assume that use was implied in your question. Your question just said experiential glider, and I want to be very clear what it will or will not do.

When it comes to airlines and fast jets visibility to them, and ATC, should always be the first goal, visibility of them is also useful of course, and in other situations visibility of other traffic become more important (e.g. you can respond more effectively to avoid slower the traffic, that traffic is less likely to have TCAS, or any traffic display system etc.)

You already have a transponder, which is great. Next question is do you have a PowerFLARM? I am guessing not, but I'll touch in that below.

First, please don't adopt UAT Out in the glider community, it is a poor choice given so many gliders have PowerFLARM and will not see your UAT position data, they will see your transponder via PCAS as long as it is being interrogated, but of course that's much less precise that FLARM or ADS-B. If you do have PowerFLARM already, OK that traffic will see you by FLARM. But 1090ES Out is still a better choice, including because it provides longer range visbility of you to all the PowerFLARM users.

Because of compatibility with PowerFLARM if you have a Mode C transponder in a glider and want to go to ADS-B Out then the much better path is to upgrade your transponder to Mode S and a suitable GPS source. Please sell or give your current Mode C transponders to another pilot or club to use.

When considering the cost of things, remember older Mode C transponder will eventually die and need to be replaced, and so why not just replace it now with a Mode S?

And that device asked about does have a dual-link UAT and 1090ES receiver which is great, but there is no way to get that data to display on common soaring flight computers, PDAs etc. You could add a dedicated display for that.

If you do want to add PowerFLARM in future that is likely to be a mess with no way to dedupe traffic from your UAT and ADS-B In system. Again, discussed a lot on r.a.s. and more info can be found by searching, I hope that problem gets solved over time.

If you do want a complete separate dual-link ADS-B In system then products like the Status S2, Statux, and uAvionix Scout, and more are options. (I don't have any personal reports of Scout use). A dual-link ADS-B In system will receive all line of sight 1090ES and UAT Out traffic. It will not receive TIS-B ground service (ADS-B data based on SSR radar) without a compliant ADS-B out system to make your aircraft an ADS-B client. (the UAT system you ask about would do that, but again your ADS-B Out won't ever be seen by PowerFLARM).

GRT avionics and uAvionix targets experimental aircraft, and your question was clearly about experimental. And no surprise that the UAT device is non-TSO. But I do get frustrated with both vendors here not providing really clear specs on their website of what the RTCA and TSO standards the product actually meet. The leading bold "meets 2020 claim" is only true for experimental aircraft, that should be even clearer.

On Thursday, September 28, 2017 at 6:53:44 PM UTC-7, Tom BravoMike wrote:
/snip/
3. Why do so many sources say: You fly above 18,000 ft? Go for 1090. You fly below? Go for 978 ? See in that respect e.g.

https://www.garmin.com/en-US/blog/av...on-is-for-you/

but disregard the specific equipment suggested.
/snip/

Tom

Sounds like you have a great handle on stuff here to help make the right decisions for you.

I would not give too much weight too much to the UAT argument in that blog. it's from several years ago, and suspect it is coming at a time where there actually started to be more 1090ES out installs in GA. Garmin might have had a sales reason around that time to mention UAT product upgrades (on the GLD88) and also may have in part just been echoing the FAAs vision for how ADS-B dual-link was going to be deployed. Today below 18,000' I think it is a good mix of UAT and 1090ES.

Some comments in the strange gymnastics behind dual-link in the USA: Originally the FAA has a view that UAT would be used for all lower altitude aircraft (then below FL240, later lowered to 18,000'), driven by concerns about 1090 MHz congestion, and likely expected costs of Mode S transponders, and likely a desire to create a user base of UAT to make FIS-B successful (and have FIS-B successful to encourage UAT adoption..). And organizations like AOPA and EAA liked the idea of keeping Mode C transponders so liked the idea of UAT, and so on.

.... but much of it is probably not true, Mode S transponders are not hugely expensive (for what they do), the rest of the word ignored UAT and went 1090ES only, so economies of there helped lower prices and will continue to, lots of folks "cheated" and got free FIS-B with portable devices without playing in ADS-B proper, ADS-B Out for many install its easier to upgrade older transponders with plug in replacements (and use existing antenna and wiring etc.) , or do a Mode S transponder firmware upgrade , etc., etc. It's a very complex system and I don't think played out as envisioned early on, really complex systems rarely do.

It seems that lots of GA folks are installing lots of different ADS-B Out stuff, in the mid-high end GA market I see people going with 1090ES Out and Dual-Link In. And not just for people who might fly in class A airspace. Much of that is driven by easy upgrades/add on to their transponders

As for PowerFLARM adoption, glider ports and operations that I know have strong adoption, most people flying cross country have it. The thing that matters is where you fly, if PowerFLARM usage is very low (and not likely to increase) then its a non-issue.

I'm not sure there us somebody else able to develop the software equivalent for ADS-B to what makes FLARM useful between gliders, usable at all in thermals etc. I've seen the issues with PowerFLARM, it was very frustrating, but I think we are on a stable/usable system now.

It is too bad we don't have an organization that would be willing to lobby the FAA to allow lower powered or experimental approved transponders and ADS-B out solutions in Certified gliders that do not have an electrical generator. Wouldn't that have been a reasonable approach for the last ten years? Why does the power requirements for transponders change at 15k rather than 18k? All things that working with the FAI might have helped the glider community in the long run.

On Thursday, September 28, 2017 at 10:14:46 PM UTC-7, Tim Taylor wrote:
It is too bad we don't have an organization that would be willing to lobby the FAA to allow lower powered or experimental approved transponders and ADS-B out solutions in Certified gliders that do not have an electrical generator. Wouldn't that have been a reasonable approach for the last ten years? Why does the power requirements for transponders change at 15k rather than 18k? All things that working with the FAI might have helped the glider community in the long run.

Being honest, the power argument is a specious excuse, at least in any serious cross country glider. The panel is full of battery powered stuff and even with old LA batteries it was not a problem to power them for 8 hours. With a single LFP mine will run about 14 hours. Including the transponder. In an old club 2-33 maybe there is an argument. It comes down to expense and installation suitability. The 145 gps units seem to require a huge wart antenna and the installation nonsense that goes with it.

On Friday, September 29, 2017 at 1:14:46 AM UTC-4, Tim Taylor wrote:
It is too bad we don't have an organization that would be willing to lobby the FAA to allow lower powered or experimental approved transponders and ADS-B out solutions in Certified gliders that do not have an electrical generator. Wouldn't that have been a reasonable approach for the last ten years? Why does the power requirements for transponders change at 15k rather than 18k? All things that working with the FAI might have helped the glider community in the long run.

Because half azzed transponder solutions are worse than no transponders. A bunch of pilots flying low power transponders powered by a hobby battery wired by an amateur and everyone assuming everything up there will be on everyone's TV is far more dangerous than knowing that there are things up there not beeping.