ADS-B Update

On Tuesday, December 12, 2017 at 3:48:05 AM UTC-6, Darryl Ramm wrote:
It must be time for some more ADS-B posts, either that or we can talk about PW5 :-)

With the ~$350 street price Trig TN72 GPS source now available in the USA I wanted to revisit my understanding of the situation with ADS-B Out in gliders. I wrote a forum post for local Northern California pilots but it probably helps lots of other folks in the USA. See https://www.williamssoaring..com/new...er-this-Winter

---

And specifically I want to correct some doubt/misinformation I've helped spread here before about the Trig TN72 GPS source when it was first announced. The TN72 is either (depending on how it is configured in the paired transponder) a:

1. TABS/TSO-C199 GPS source (with SIL=1)

*or*

2. A "meets performance requirement of TSO-C145c" GPS source (language I prefer, although Trig may say it differently) (with SIL=3)

(OK the TN72 can also do plain NMEA (with SIL=0), but that's not intersting here).

A little more details and the implications of this is described in post linked to above.

It would be great for folks doing 1090ES Out installs to share their experiences. Here, or contact me directly,

I am happy to try to answer questions.

I'm also planning to give a few talks on ADS-B (and FLARM and Transponders) over the next few months, certainly on the West Coast, details later.

Darryl

Darryl I need to talk to you off line on this subject, Please email you contact info. thxs

There's someone in my club (we're Canadian but he's thinking of doing a fair amount of soaring in the U.S. in the future now that he has his own ship) who is considering transponder installation and ADS-B. If I understand the article if he wants full 2020 compliance the way to go right now would be a Trig TT22 (the transponder he is thinking of buying) combined with the TN70/TA70 correct? Antennas shouldn't be a problem as it's an early ASW-20.

If you want to talk about the PW-5, well I also know another Canadian pilot who owns one and flies it exclusively in the U.S. When she installed a Trig T22 and Powerflarm last winter the avionics shop did run the NMEA output from the Powrflarm to the transponder. From my reading of your article I gather this would A: not provide any official compliance with ADS-B requirements (they didn't think it would) and B: the output would show up on some ADS-B-in equipment but not the certified ones, or any of the ground based systems? I would be interested in the rationale behind that decision.

Thanks for the article and the posts.

On Thursday, December 14, 2017 at 11:29:04 AM UTC-8, wrote:
There's someone in my club (we're Canadian but he's thinking of doing a fair amount of soaring in the U.S. in the future now that he has his own ship) who is considering transponder installation and ADS-B. If I understand the article if he wants full 2020 compliance the way to go right now would be a Trig TT22 (the transponder he is thinking of buying) combined with the TN70/TA70 correct? Antennas shouldn't be a problem as it's an early ASW-20.

If you want to talk about the PW-5, well I also know another Canadian pilot who owns one and flies it exclusively in the U.S. When she installed a Trig T22 and Powerflarm last winter the avionics shop did run the NMEA output from the Powrflarm to the transponder. From my reading of your article I gather this would A: not provide any official compliance with ADS-B requirements (they didn't think it would) and B: the output would show up on some ADS-B-in equipment but not the certified ones, or any of the ground based systems? I would be interested in the rationale behind that decision.

Thanks for the article and the posts.

Dealing with Canadian registered aircraft and compliance with USA regulations is well beyond my area of comfort. Even the approval process for doing installation of a transponder in Canada is not something I have any understanding of. Canada has nothing like the 2020 Compliance regulations in the USA. OTOH folks in the GA avionics business in Canada might be able to help discuss how they do USA complaint ADS-B Out installs for GA aircraft planning on crossing the border.

The simplest thing may be not to worry about seeking 2020 Compliance unless there is a reason you need to, just install a TN72 for TABS output in the glider, do that install with SIL=1.

---

PowerFLARM NMEA Out connected to a TT22 or TT21 in the USA provides...

o Long range visibility to other PowerFLARM (with 1090ES In option) equipped gliders, hopefully to several tens of miles.
o Visibility to GA aircraft with portable ADS-B 1090ES In or dual link receivers (not UAT only receivers)
o Visibility to TCAS I and II, military IFF, and PCAS systems via the basic transponder
o Visibility to ATC via SSR when within radar range via the basic transponder

It does not provide
o Visibility to aircraft with IFR/panel mount ADS-B 1090ES In traffic displays
o ADS-B vsibility to ATC (but you have visibility via transponder when within SSR coverage)
o Visibility to aircraft with any UAT In only receivers (portable or panel mount).
o Does not make the aircraft an ADS-R and TIS-B client aircraft (which PowerFLARM won't decode anyhow).

Now the TN72 is available it probably makes sense for any people who have a SIL=0 install to replace that PowerFLARN or other NMEA connection with a Trig TN72 GPS to at least get a TABS install.

On Thursday, December 14, 2017 at 12:40:07 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 11:29:04 AM UTC-8, wrote:
There's someone in my club (we're Canadian but he's thinking of doing a fair amount of soaring in the U.S. in the future now that he has his own ship) who is considering transponder installation and ADS-B. If I understand the article if he wants full 2020 compliance the way to go right now would be a Trig TT22 (the transponder he is thinking of buying) combined with the TN70/TA70 correct? Antennas shouldn't be a problem as it's an early ASW-20.

If you want to talk about the PW-5, well I also know another Canadian pilot who owns one and flies it exclusively in the U.S. When she installed a Trig T22 and Powerflarm last winter the avionics shop did run the NMEA output from the Powrflarm to the transponder. From my reading of your article I gather this would A: not provide any official compliance with ADS-B requirements (they didn't think it would) and B: the output would show up on some ADS-B-in equipment but not the certified ones, or any of the ground based systems? I would be interested in the rationale behind that decision.

Thanks for the article and the posts.

Dealing with Canadian registered aircraft and compliance with USA regulations is well beyond my area of comfort. Even the approval process for doing installation of a transponder in Canada is not something I have any understanding of. Canada has nothing like the 2020 Compliance regulations in the USA. OTOH folks in the GA avionics business in Canada might be able to help discuss how they do USA complaint ADS-B Out installs for GA aircraft planning on crossing the border.

The simplest thing may be not to worry about seeking 2020 Compliance unless there is a reason you need to, just install a TN72 for TABS output in the glider, do that install with SIL=1.

---

PowerFLARM NMEA Out connected to a TT22 or TT21 in the USA provides...

o Long range visibility to other PowerFLARM (with 1090ES In option) equipped gliders, hopefully to several tens of miles.
o Visibility to GA aircraft with portable ADS-B 1090ES In or dual link receivers (not UAT only receivers)
o Visibility to TCAS I and II, military IFF, and PCAS systems via the basic transponder
o Visibility to ATC via SSR when within radar range via the basic transponder

It does not provide
o Visibility to aircraft with IFR/panel mount ADS-B 1090ES In traffic displays
o ADS-B vsibility to ATC (but you have visibility via transponder when within SSR coverage)
o Visibility to aircraft with any UAT In only receivers (portable or panel mount).
o Does not make the aircraft an ADS-R and TIS-B client aircraft (which PowerFLARM won't decode anyhow).

Now the TN72 is available it probably makes sense for any people who have a SIL=0 install to replace that PowerFLARN or other NMEA connection with a Trig TN72 GPS to at least get a TABS install.

Would only provide visibility to gliders and portable or panel mount receivers inside of radar coverage? Needs to be pinged to broadcast, no? (OK that's a lot of places but not everywhere).

On Thursday, December 14, 2017 at 4:04:16 PM UTC-8, jfitch wrote:
On Thursday, December 14, 2017 at 12:40:07 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 11:29:04 AM UTC-8, wrote:
There's someone in my club (we're Canadian but he's thinking of doing a fair amount of soaring in the U.S. in the future now that he has his own ship) who is considering transponder installation and ADS-B. If I understand the article if he wants full 2020 compliance the way to go right now would be a Trig TT22 (the transponder he is thinking of buying) combined with the TN70/TA70 correct? Antennas shouldn't be a problem as it's an early ASW-20.

If you want to talk about the PW-5, well I also know another Canadian pilot who owns one and flies it exclusively in the U.S. When she installed a Trig T22 and Powerflarm last winter the avionics shop did run the NMEA output from the Powrflarm to the transponder. From my reading of your article I gather this would A: not provide any official compliance with ADS-B requirements (they didn't think it would) and B: the output would show up on some ADS-B-in equipment but not the certified ones, or any of the ground based systems? I would be interested in the rationale behind that decision.

Thanks for the article and the posts.

Dealing with Canadian registered aircraft and compliance with USA regulations is well beyond my area of comfort. Even the approval process for doing installation of a transponder in Canada is not something I have any understanding of. Canada has nothing like the 2020 Compliance regulations in the USA. OTOH folks in the GA avionics business in Canada might be able to help discuss how they do USA complaint ADS-B Out installs for GA aircraft planning on crossing the border.

The simplest thing may be not to worry about seeking 2020 Compliance unless there is a reason you need to, just install a TN72 for TABS output in the glider, do that install with SIL=1.

---

PowerFLARM NMEA Out connected to a TT22 or TT21 in the USA provides...

o Long range visibility to other PowerFLARM (with 1090ES In option) equipped gliders, hopefully to several tens of miles.
o Visibility to GA aircraft with portable ADS-B 1090ES In or dual link receivers (not UAT only receivers)
o Visibility to TCAS I and II, military IFF, and PCAS systems via the basic transponder
o Visibility to ATC via SSR when within radar range via the basic transponder

It does not provide
o Visibility to aircraft with IFR/panel mount ADS-B 1090ES In traffic displays
o ADS-B vsibility to ATC (but you have visibility via transponder when within SSR coverage)
o Visibility to aircraft with any UAT In only receivers (portable or panel mount).
o Does not make the aircraft an ADS-R and TIS-B client aircraft (which PowerFLARM won't decode anyhow).

Now the TN72 is available it probably makes sense for any people who have a SIL=0 install to replace that PowerFLARN or other NMEA connection with a Trig TN72 GPS to at least get a TABS install.

Would only provide visibility to gliders and portable or panel mount receivers inside of radar coverage? Needs to be pinged to broadcast, no? (OK that's a lot of places but not everywhere).

Jon. I not sure specifically what part you are asking a question about.

ADS-B anything does not rely on a transponders being interrogated. Extended Squitter stuff is separate to interrogation responses. If you have a transponder with a GPS connected and its transmitting ADS-B Out at any SIL level then PowerFLARM and portable 1090ES ADS-B In receivers should see you. (I can't assure you for sure that SIL=0 will be seen ion every device, a portable manufacturer might decide to require SIL=1, not sure why they would but they could... ).

PCAS relies on an external interrogator. SSR or one of the ones below...

TCAS I, II, TCAD and IFF all are their own active interrogators and do not require the target to be near ground based SSR.

On Thursday, December 14, 2017 at 4:27:39 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 4:04:16 PM UTC-8, jfitch wrote:
On Thursday, December 14, 2017 at 12:40:07 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 11:29:04 AM UTC-8, wrote:
There's someone in my club (we're Canadian but he's thinking of doing a fair amount of soaring in the U.S. in the future now that he has his own ship) who is considering transponder installation and ADS-B. If I understand the article if he wants full 2020 compliance the way to go right now would be a Trig TT22 (the transponder he is thinking of buying) combined with the TN70/TA70 correct? Antennas shouldn't be a problem as it's an early ASW-20.

If you want to talk about the PW-5, well I also know another Canadian pilot who owns one and flies it exclusively in the U.S. When she installed a Trig T22 and Powerflarm last winter the avionics shop did run the NMEA output from the Powrflarm to the transponder. From my reading of your article I gather this would A: not provide any official compliance with ADS-B requirements (they didn't think it would) and B: the output would show up on some ADS-B-in equipment but not the certified ones, or any of the ground based systems? I would be interested in the rationale behind that decision.

Thanks for the article and the posts.

Dealing with Canadian registered aircraft and compliance with USA regulations is well beyond my area of comfort. Even the approval process for doing installation of a transponder in Canada is not something I have any understanding of. Canada has nothing like the 2020 Compliance regulations in the USA. OTOH folks in the GA avionics business in Canada might be able to help discuss how they do USA complaint ADS-B Out installs for GA aircraft planning on crossing the border.

The simplest thing may be not to worry about seeking 2020 Compliance unless there is a reason you need to, just install a TN72 for TABS output in the glider, do that install with SIL=1.

---

PowerFLARM NMEA Out connected to a TT22 or TT21 in the USA provides....

o Long range visibility to other PowerFLARM (with 1090ES In option) equipped gliders, hopefully to several tens of miles.
o Visibility to GA aircraft with portable ADS-B 1090ES In or dual link receivers (not UAT only receivers)
o Visibility to TCAS I and II, military IFF, and PCAS systems via the basic transponder
o Visibility to ATC via SSR when within radar range via the basic transponder

It does not provide
o Visibility to aircraft with IFR/panel mount ADS-B 1090ES In traffic displays
o ADS-B vsibility to ATC (but you have visibility via transponder when within SSR coverage)
o Visibility to aircraft with any UAT In only receivers (portable or panel mount).
o Does not make the aircraft an ADS-R and TIS-B client aircraft (which PowerFLARM won't decode anyhow).

Now the TN72 is available it probably makes sense for any people who have a SIL=0 install to replace that PowerFLARN or other NMEA connection with a Trig TN72 GPS to at least get a TABS install.

Would only provide visibility to gliders and portable or panel mount receivers inside of radar coverage? Needs to be pinged to broadcast, no? (OK that's a lot of places but not everywhere).

Jon. I not sure specifically what part you are asking a question about.

ADS-B anything does not rely on a transponders being interrogated. Extended Squitter stuff is separate to interrogation responses. If you have a transponder with a GPS connected and its transmitting ADS-B Out at any SIL level then PowerFLARM and portable 1090ES ADS-B In receivers should see you. (I can't assure you for sure that SIL=0 will be seen ion every device, a portable manufacturer might decide to require SIL=1, not sure why they would but they could... ).

PCAS relies on an external interrogator. SSR or one of the ones below...

TCAS I, II, TCAD and IFF all are their own active interrogators and do not require the target to be near ground based SSR.

OK, so ADS-B information is transmitted in the blind?

On Thursday, December 14, 2017 at 7:20:02 PM UTC-8, jfitch wrote:

OK, so ADS-B information is transmitted in the blind?

Yep. Completely blind/automatic. That is what the A in ADS-B stands for.

Automatic Dependent Surveillance - Broadcast

Dependent meaning GNSS/GPS.

ADS-B Out broadcasts data messages several times per second completely autonomously, with some pseudorandom time dither to avoid correlated collisions. The mix is a bit complex with ID, status, position and velocity messages broadcast at different rates. Position and velocity are twice per second.

The ADS-B Out side of things make no response to any interrogation and cannot tell if anything is listening. 1090ES Out systems are in practice parts of Mode S transponders and so have a whole slew of other things they do including other automatic broadcasts (like acquisition squitters) and multiple different interrogation types and on high-end transponder even air-air data link for TCAS resolution coordination, etc.. Way more complex than legacy Mode A/C transponders.... and so complex you can see why the expectation back in the early days of ADS-B planning seemed to be that Mode S transponder costs were going to remain high, and why UAT might be a good idea... well no because FPGAs and fast microcontrollers happened and turned transponder hardware into a software problem...

On Thursday, December 14, 2017 at 8:30:06 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 7:20:02 PM UTC-8, jfitch wrote:

OK, so ADS-B information is transmitted in the blind?

Yep. Completely blind/automatic. That is what the A in ADS-B stands for.

Automatic Dependent Surveillance - Broadcast

Dependent meaning GNSS/GPS.

ADS-B Out broadcasts data messages several times per second completely autonomously, with some pseudorandom time dither to avoid correlated collisions. The mix is a bit complex with ID, status, position and velocity messages broadcast at different rates. Position and velocity are twice per second..

The ADS-B Out side of things make no response to any interrogation and cannot tell if anything is listening. 1090ES Out systems are in practice parts of Mode S transponders and so have a whole slew of other things they do including other automatic broadcasts (like acquisition squitters) and multiple different interrogation types and on high-end transponder even air-air data link for TCAS resolution coordination, etc.. Way more complex than legacy Mode A/C transponders.... and so complex you can see why the expectation back in the early days of ADS-B planning seemed to be that Mode S transponder costs were going to remain high, and why UAT might be a good idea... well no because FPGAs and fast microcontrollers happened and turned transponder hardware into a software problem...

One more thing: if you get the TN72 you will also have to get a TSO'd antenna. So what, you say. Well the antenna costs as much as the TN72.

Tom

On Thursday, December 14, 2017 at 9:39:35 PM UTC-8, 2G wrote:
On Thursday, December 14, 2017 at 8:30:06 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 7:20:02 PM UTC-8, jfitch wrote:

OK, so ADS-B information is transmitted in the blind?

Yep. Completely blind/automatic. That is what the A in ADS-B stands for..

Automatic Dependent Surveillance - Broadcast

Dependent meaning GNSS/GPS.

ADS-B Out broadcasts data messages several times per second completely autonomously, with some pseudorandom time dither to avoid correlated collisions. The mix is a bit complex with ID, status, position and velocity messages broadcast at different rates. Position and velocity are twice per second.

The ADS-B Out side of things make no response to any interrogation and cannot tell if anything is listening. 1090ES Out systems are in practice parts of Mode S transponders and so have a whole slew of other things they do including other automatic broadcasts (like acquisition squitters) and multiple different interrogation types and on high-end transponder even air-air data link for TCAS resolution coordination, etc.. Way more complex than legacy Mode A/C transponders.... and so complex you can see why the expectation back in the early days of ADS-B planning seemed to be that Mode S transponder costs were going to remain high, and why UAT might be a good idea... well no because FPGAs and fast microcontrollers happened and turned transponder hardware into a software problem...

One more thing: if you get the TN72 you will also have to get a TSO'd antenna. So what, you say. Well the antenna costs as much as the TN72.

Tom

I would hope not, the thing is ugly as hell. If your glider is experimental there is no way I'd expect folks to install that, if certified ask your A&P IA what they want to see to sign off on a minor alteration to do a TABS install.

On Thursday, December 14, 2017 at 9:54:54 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 9:39:35 PM UTC-8, 2G wrote:
On Thursday, December 14, 2017 at 8:30:06 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 7:20:02 PM UTC-8, jfitch wrote:

OK, so ADS-B information is transmitted in the blind?

Yep. Completely blind/automatic. That is what the A in ADS-B stands for.

Automatic Dependent Surveillance - Broadcast

Dependent meaning GNSS/GPS.

ADS-B Out broadcasts data messages several times per second completely autonomously, with some pseudorandom time dither to avoid correlated collisions. The mix is a bit complex with ID, status, position and velocity messages broadcast at different rates. Position and velocity are twice per second.

The ADS-B Out side of things make no response to any interrogation and cannot tell if anything is listening. 1090ES Out systems are in practice parts of Mode S transponders and so have a whole slew of other things they do including other automatic broadcasts (like acquisition squitters) and multiple different interrogation types and on high-end transponder even air-air data link for TCAS resolution coordination, etc.. Way more complex than legacy Mode A/C transponders.... and so complex you can see why the expectation back in the early days of ADS-B planning seemed to be that Mode S transponder costs were going to remain high, and why UAT might be a good idea.... well no because FPGAs and fast microcontrollers happened and turned transponder hardware into a software problem...

One more thing: if you get the TN72 you will also have to get a TSO'd antenna. So what, you say. Well the antenna costs as much as the TN72.

Tom

I would hope not, the thing is ugly as hell. If your glider is experimental there is no way I'd expect folks to install that, if certified ask your A&P IA what they want to see to sign off on a minor alteration to do a TABS install.

Hoping isn't a part of an inspection: if it isn't TSO'd how can it be signed off by an IA?