Flarm suppression of ADS-B out on Tow Planes

[[email protected]]

For those towing behind tow planes equipped with ADS-B out (1090MHz), a new version of PowerFlarm firmware 6.67 is now available which should suppress the collision warning from the tow plane's ADS-B out. Below are release notes.

Version 6.67
Published 04 March 2019
Platforms Build Expiration
All PowerFLARM- and Classic FLARM-based devices a072808ac
Not operational after 31 October 2020
Changes since 6.63 Enhancements
 PowerFLARM: Suppress warnings from tow aircraft equipped with ADS-B Out, but not FLARM
 All: Info Alarms/traffic advisories in saturated situations are moderated such that they can no longer be mistaken as full traffic alarms

Thanks to Jerome at Flarm for working on providing this enhancement.

GC

[JS[_5_]]

On Tuesday, March 19, 2019 at 1:54:40 PM UTC-7, wrote:
> For those towing behind tow planes equipped with ADS-B out (1090MHz), a new version of PowerFlarm firmware 6.67 is now available which should suppress the collision warning from the tow plane's ADS-B out. Below are release notes.
>
> Version 6.67
> Published 04 March 2019
> Platforms Build Expiration
> All PowerFLARM- and Classic FLARM-based devices a072808ac
> Not operational after 31 October 2020
> Changes since 6.63 Enhancements
>  PowerFLARM: Suppress warnings from tow aircraft equipped with ADS-B Out, but not FLARM
>  All: Info Alarms/traffic advisories in saturated situations are moderated such that they can no longer be mistaken as full traffic alarms
>
> Thanks to Jerome at Flarm for working on providing this enhancement.
>
> GC

Thanks, just updated. The display shows v6.67, took 5 minutes.
Looking forward to trying that.
Jim

[[email protected]]

On Tuesday, March 19, 2019 at 4:54:40 PM UTC-4, wrote:
> For those towing behind tow planes equipped with ADS-B out (1090MHz), a new version of PowerFlarm firmware 6.67 is now available which should suppress the collision warning from the tow plane's ADS-B out. Below are release notes.


What about those tow planes equipped with ADS-B out using UAT (978MHz)?

[kinsell]

On 3/19/19 4:50 PM, wrote:
> On Tuesday, March 19, 2019 at 4:54:40 PM UTC-4, wrote:
>> For those towing behind tow planes equipped with ADS-B out (1090MHz), a new version of PowerFlarm firmware 6.67 is now available which should suppress the collision warning from the tow plane's ADS-B out. Below are release notes.
>
>
> What about those tow planes equipped with ADS-B out using UAT (978MHz)?
>

PF doesn't receive 978 MHz, so there shouldn't be alarms generated.

[Ramy[_2_]]

On Tuesday, March 19, 2019 at 3:50:19 PM UTC-7, wrote:
> On Tuesday, March 19, 2019 at 4:54:40 PM UTC-4, wrote:
> > For those towing behind tow planes equipped with ADS-B out (1090MHz), a new version of PowerFlarm firmware 6.67 is now available which should suppress the collision warning from the tow plane's ADS-B out. Below are release notes.
>
>
> What about those tow planes equipped with ADS-B out using UAT (978MHz)?

UAT is not showing in powerflarm anyway.

This is great news. I am curious how the new suppression determine the ADSB signal is from the tow plane. I guess the suppression will work similarly for any formation flying, which is a good thing.

Ramy

[Darryl Ramm]

On Tuesday, March 19, 2019 at 4:05:58 PM UTC-7, kinsell wrote:
> On 3/19/19 4:50 PM, wrote:
> > On Tuesday, March 19, 2019 at 4:54:40 PM UTC-4, wrote:
> >> For those towing behind tow planes equipped with ADS-B out (1090MHz), a new version of PowerFlarm firmware 6.67 is now available which should suppress the collision warning from the tow plane's ADS-B out. Below are release notes.
> >
> >
> > What about those tow planes equipped with ADS-B out using UAT (978MHz)?
> >
>
> PF doesn't receive 978 MHz, so there shouldn't be alarms generated.

Jeez is there anybody who has not been paying attention who actually has equipped a tow plane with UAT Out?

[Mike Schumann[_2_]]

On Tuesday, March 19, 2019 at 7:18:33 PM UTC-4, Darryl Ramm wrote:
> On Tuesday, March 19, 2019 at 4:05:58 PM UTC-7, kinsell wrote:
> > On 3/19/19 4:50 PM, wrote:
> > > On Tuesday, March 19, 2019 at 4:54:40 PM UTC-4, wrote:
> > >> For those towing behind tow planes equipped with ADS-B out (1090MHz), a new version of PowerFlarm firmware 6.67 is now available which should suppress the collision warning from the tow plane's ADS-B out. Below are release notes.
> > >
> > >
> > > What about those tow planes equipped with ADS-B out using UAT (978MHz)?
> > >
> >
> > PF doesn't receive 978 MHz, so there shouldn't be alarms generated.
>
> Jeez is there anybody who has not been paying attention who actually has equipped a tow plane with UAT Out?

skyBeacon is a pretty darn inexpensive and easy to implement way to make a tow plane 2020 compliant. I wouldn't be surprised if a significant number of people don't go that route, even though it is UAT instead of 1090ES.

A big question is exactly how FLARM has suppressed the tow plane ADS-B alarms. Does FLARM recognize the fact that the tow plane and glider are in formation, and only suppress the alarm while the formation flight continues, or does it somehow completely suppress all alarms for the tow plane? You definitely would want to see tow plane alarms after the glider releases from the tow in the event that you accidentally get on a collision course with the tow plane after the completion of the tow.

[Andy Blackburn[_3_]]

These seem to me to be two examples of difficulty assessing the number of decimal places in looking at probabilities.

Equipping a towplane with UAT says an owner is willing to spend money on ADS-B, but not the flavor that represents the vast majority of collision threats (it's a glider towplane after all). That just seems dopey. UAT is problematic for other reasons too in that it requires ADS-R or a dual-band receiver to be seen by the vast majority of aircraft that have opted for 1090ES and towplanes tend to operate down low where ADS-R services may not be available for other powered traffic. A waste of money that simultaneously makes other people's lives less safe and more difficult. Buying something that's far less likely to work because it's cheap hardly seems like a smart buy.

I doubt that Flarm would pick an algorithm that can both identify what's a towplane through formation flight and then blank out the ADS-B ICAO address and never check for towplane behavior again - but even if it did the probability of a towplane releasing a glider and circling around in a climb to become a collision threat seems like and extremely low probability scenario and not a reason to reject/critique the idea of towplane suppression. In 46 years of glider flying I've never, ever seen a towplane do that. Either way towplane suppression is a good idea and I tend to think the Flarm folks are pretty clever. I look forward to trying it out.

Andy Blackburn


On Tuesday, March 19, 2019 at 8:44:42 PM UTC-5, Mike Schumann wrote:
> skyBeacon is a pretty darn inexpensive and easy to implement way to make a tow plane 2020 compliant. I wouldn't be surprised if a significant number of people don't go that route, even though it is UAT instead of 1090ES.
>
> A big question is exactly how FLARM has suppressed the tow plane ADS-B alarms. Does FLARM recognize the fact that the tow plane and glider are in formation, and only suppress the alarm while the formation flight continues, or does it somehow completely suppress all alarms for the tow plane? You definitely would want to see tow plane alarms after the glider releases from the tow in the event that you accidentally get on a collision course with the tow plane after the completion of the tow.

[Darryl Ramm]

On Tuesday, March 19, 2019 at 6:44:42 PM UTC-7, Mike Schumann wrote:

>
> skyBeacon is a pretty darn inexpensive and easy to implement way to make a tow plane 2020 compliant. I wouldn't be surprised if a significant number of people don't go that route, even though it is UAT instead of 1090ES.
>

That would be the stupidest thing in the world. "significant number".... bull****. There are very few towplanes anywhere that I know of that are planning to equip with ADS-B Out for 2020 compliance reasons. I'm not aware of any of them going UAT, I had one question asked months ago and that person went away understanding why to use 1090ES Out not UAT. I only hear about ADS-B Out installs that folks ask for help with, but by now I'd hope that enough people know to keep UAT away from PowerFLARM equipped gliders.

[Ramy[_2_]]

Andy, I know of two mid airs between a tow plane and the glider it just released. One luckily just exchanged some paint, the other was fatal to both pilots. So I would hope and expect the suppression is only during the tow.

Ramy

[Charles Longley]

Must be a lot of stupid pilots! uAvionix is backed up close to a month on skyBeacon orders.....

[Darryl Ramm]

.... around gliders. You have been here on r.a.s enough that if you do not understand the issues and context by now you never will.

[JS[_5_]]

On Tuesday, March 19, 2019 at 6:44:42 PM UTC-7, Mike Schumann wrote:
>
> skyBeacon is a pretty darn inexpensive and easy to implement way to make a tow plane 2020 compliant. I wouldn't be surprised if a significant number of people don't go that route, even though it is UAT instead of 1090ES.
>
> A big question is exactly how FLARM has suppressed the tow plane ADS-B alarms. Does FLARM recognize the fact that the tow plane and glider are in formation, and only suppress the alarm while the formation flight continues, or does it somehow completely suppress all alarms for the tow plane? You definitely would want to see tow plane alarms after the glider releases from the tow in the event that you accidentally get on a collision course with the tow plane after the completion of the tow.

Good question Mike.
If the towplane was FLARM equipped, it wouldn't be annoying as hell like ADS-B alone is - or possibly was before this update. We'll see.

Don't understand why there is the UAT crap. Nobody else uses it.

If both towplane and glider were just ADS-B equipped, what sort of alarms go off? Is ADS-B-in intelligent enough to suppress alarms for formation flying?

I've towed behind FLARM-only towplanes, there is no noise on tow.
Jim

[Andy Blackburn[_3_]]

On Tuesday, March 19, 2019 at 10:59:46 PM UTC-5, Ramy wrote:
> Andy, I know of two mid airs between a tow plane and the glider it just released. One luckily just exchanged some paint, the other was fatal to both pilots. So I would hope and expect the suppression is only during the tow.
>
> Ramy

If the fatal is the one I'm thinking of wasn't that on turn to final on a wave day? I'm thinking that would be long enough to reset even the most poorly designed algorithm. It's not like they're going to make a list of ICAO addresses that never ever get to be targets again. On the other hand, I could imagine some algorithms that might not alarm if you overrun the towplane while on tow or dive at the towplane immediately after release and never get much farther away than 200'. OTOH, maybe they handle that too. If they don't I'm fine and thankful for the quiet. I can keep an eye on the plane right in front of me.

We'll just have to see. Hopefully the algorithm mechanism and criteria for detecting an aircraft as towing you and the mechanism for removing them from 'your towplane' status will be in the release notes. The Flarm guys are clever so I bet they have thought through most scenarios.

Andy

[Urban]

> A big question is exactly how FLARM has suppressed the tow plane ADS-B alarms. Does FLARM recognize the fact that the tow plane and glider are in formation, and only suppress the alarm while the formation flight continues, or does it somehow completely suppress all alarms for the tow plane? You definitely would want to see tow plane alarms after the glider releases from the tow in the event that you accidentally get on a collision course with the tow plane after the completion of the tow.

Fair question! The suppression works on the geometry of the formation, namely relative headings, relative velocities, relative positions (i.e. vertical and horizontal separation). As soon as the conditions no longer hold, you will get alarms as normal.

This is unchanged to how tow trains are handled in FLARM-FLARM situations. The difference is that for ADS-B targets, the device does not know it is a tow plane - ADS-B simply does not give you this kind of metadata - so the logic is applied to all ADS-B targets. As the geometric conditions are really tight, we believe this is acceptable and will not lead to false negatives..

We are interested to hear how well this works, please do send us feedback!

- Urban, FLARM

[Mike Schumann[_2_]]

On Tuesday, March 19, 2019 at 11:46:10 PM UTC-4, Darryl Ramm wrote:
> On Tuesday, March 19, 2019 at 6:44:42 PM UTC-7, Mike Schumann wrote:
>
> >
> > skyBeacon is a pretty darn inexpensive and easy to implement way to make a tow plane 2020 compliant. I wouldn't be surprised if a significant number of people don't go that route, even though it is UAT instead of 1090ES.
> >
>
> That would be the stupidest thing in the world. "significant number".... bull****. There are very few towplanes anywhere that I know of that are planning to equip with ADS-B Out for 2020 compliance reasons. I'm not aware of any of them going UAT, I had one question asked months ago and that person went away understanding why to use 1090ES Out not UAT. I only hear about ADS-B Out installs that folks ask for help with, but by now I'd hope that enough people know to keep UAT away from PowerFLARM equipped gliders.

The stupidest thing in the world is that PowerFlarm doesn't support ADS-R or TIS-B. The fact of the matter is that UAT exists in the US and a significant number of GA aircraft are going to use this technology whether or not they are tow planes. We have 30+ gliders operating out of Stanton MN, within the MSP Mode C veil. At least half of the mid-air threats are not gliders, but other GA aircraft operating in our airspace. Not only do gliders need to be visible to this traffic, but they should also be equipped with real, US standards compliant ADS-B IN receivers (preferably dual frequency) so they can see all of the non-glider traffic in the area.

[Andy Blackburn[_3_]]

On Wednesday, March 20, 2019 at 8:43:50 AM UTC-5, Mike Schumann wrote:

> The stupidest thing in the world is that PowerFlarm doesn't support ADS-R or TIS-B.

That was a mistake and as I understand it a long story. I hope they find a way to fix it, but the US is a tiny market. The only dumber mistake was the US deploying UAT instead of sunsetting Mode C transponders and adopting 1090ES exclusively like Europe. UAT causes innumerable problems in the airspace - as evidenced by this discussion. ADS-R is not a panacea either - you have to be within range of an ADS-B ground station.

We made a fork in the Stratux code to put out NMEA for glider instruments. It works but the mixing of all the different sources made de-duplicating targets quite challenging.

For goodness sake if you are going to put ADS-B in an aircraft that tows, put in 1090ES. There aren't going to be any UAT gliders out there and a tiny fraction of powered aircraft will have UAT - especially true if you fly any where near a commercial airport. If you're worried about the stray UAT target, get a dual-band receiver.

Thanks Urban for the clarification. Nature abhors a vacuum and then people tend to connect the dots in the most pathological way possible.

Andy Blackburn
PowerFLARM, Trig TT-22 with 1090ES Out

[Darryl Ramm]

You are back whining about stuff we all know about and we can't change. We live in an imperfect world with an imperfect technology. But as I've said before here, perfect is the enemy of good and the goal we all should have is to help reduce risks and improve safety.

To that point it would be incredibly stupid to be operating a UAT Out equipped towplane where there is a fleet of PowerFLARM equipped gliders. There is just no way to sugar coat that stupidity.

And again you are using examples of Stanton MN. Sounds like there are lots of traffic concerns there. If so some of the GA traffic risks should be able to be reduced today by equipping gliders and towplanes with transponders. If it is such a problem I would hope there is 100% transponder carriage.


On Wednesday, March 20, 2019 at 6:43:50 AM UTC-7, Mike Schumann wrote:
> On Tuesday, March 19, 2019 at 11:46:10 PM UTC-4, Darryl Ramm wrote:
> > On Tuesday, March 19, 2019 at 6:44:42 PM UTC-7, Mike Schumann wrote:
> >
> > >
> > > skyBeacon is a pretty darn inexpensive and easy to implement way to make a tow plane 2020 compliant. I wouldn't be surprised if a significant number of people don't go that route, even though it is UAT instead of 1090ES.
> > >
> >
> > That would be the stupidest thing in the world. "significant number"..... bull****. There are very few towplanes anywhere that I know of that are planning to equip with ADS-B Out for 2020 compliance reasons. I'm not aware of any of them going UAT, I had one question asked months ago and that person went away understanding why to use 1090ES Out not UAT. I only hear about ADS-B Out installs that folks ask for help with, but by now I'd hope that enough people know to keep UAT away from PowerFLARM equipped gliders.
>
> The stupidest thing in the world is that PowerFlarm doesn't support ADS-R or TIS-B. The fact of the matter is that UAT exists in the US and a significant number of GA aircraft are going to use this technology whether or not they are tow planes. We have 30+ gliders operating out of Stanton MN, within the MSP Mode C veil. At least half of the mid-air threats are not gliders, but other GA aircraft operating in our airspace. Not only do gliders need to be visible to this traffic, but they should also be equipped with real, US standards compliant ADS-B IN receivers (preferably dual frequency) so they can see all of the non-glider traffic in the area.

[Charles Longley]

Lot of people calling each other stupid on here....

I’ve installed a lot of different ADS-B out systems. If it was my personal power airplane I would put in an ESGi transponder. I was recently involved in a Trig ADS-B out transponder installation. It’s a very elegant solution for a glider.

If I was going to put an UAT system in it would probably be a GDL 82. The skyBeacon is quick, easy and cheap but I would worry about the impact of the lawsuit between Garmin and uAvionix.

A skyBeacon would be better then nothing in a tow plane. I’ve had more close calls with power planes while towing and flying gliders then with other gliders. Installed the skyBeacon is around $2,000 compared to the ESGi’s $5,000.

My experienced 2 cents

[Darryl Ramm]

On Wednesday, March 20, 2019 at 9:01:06 PM UTC-7, Charles Longley wrote:
> Lot of people calling each other stupid on here....
>
> I’ve installed a lot of different ADS-B out systems. If it was my personal power airplane I would put in an ESGi transponder. I was recently involved in a Trig ADS-B out transponder installation. It’s a very elegant solution for a glider.
>
> If I was going to put an UAT system in it would probably be a GDL 82. The skyBeacon is quick, easy and cheap but I would worry about the impact of the lawsuit between Garmin and uAvionix.
>
> A skyBeacon would be better then nothing in a tow plane. I’ve had more close calls with power planes while towing and flying gliders then with other gliders. Installed the skyBeacon is around $2,000 compared to the ESGi’s $5,000.
>
> My experienced 2 cents

I have no idea where you fly gliders and how many of those are PowerFLARM equipped.

Please lets not paint the picture that it's a $2k vs $5k price difference for UAT vs 1090ES in a towplane. An Appareo Stratus ESG at ~$3k is a better comparison, including because you are comparing the price of a UAT Out only skyBeacon to a 1090ES Out/Dual-link In packaged ESGi.

Another good choice is Garmin GTX-335 ~$3k (with integral GPS option) or so plus install. Maybe better with support and service availability. Like the Stratus ESG, it is Mode S/1090ES Out with integral GPS. I am not sure how many tow pilots want ADS-B traffic-in or how many tow plane owners want to pay for that. One of Appareo's great service to GA has been pushing Garmin down on GTX-335 pricing. That extra $1k - $1.5k should not be a huge difference to go with the non-stupid for PowerFLARM compatibility option.

And it seem some towplanes in areas where ADS-B Out may be needed by them after January 1 2020, have aging mode C transponders (like crusty old KT76), so there is likely a benefit in those owners upgrading to a new transponder as part of any upgrade. To quantify that, a towplane owner could say upgrade to a more modern used GTX-330 Mode C transponder for ~$500-$1k or so. So in those cases a GTX-335 or ESG transponder for 1090ES Out and skyBeacon UAT Out effective cost likely gets close. And a Mode S+1090ES transponder in a towplane as part of an ADS-B Out upgrade is even nicer to have near high-density PowerFLARM operations to help avoid spurious Mode C PCAS alerts that Mode C equipped towplanes can cause.

Interesting comment on the lawsuit. I'm not a fan of the skyBeacon or Garmin headless setups, would prefer direct hardwired control of squawk and other settings and access to other controls on the panel. I wonder how skyBeacons are going to work in rental aircraft if somebody messes with the settings vis their iPhone and the next pilot renting it can't even see what stuff is set to. You naturally get better usability with integrated transponder solutions... but thats more a connivence not the main reason to go there.

[Charles Longley]

All good points!

I fly out of Arlington, WA about half the time. It can be a F-ing zoo! Every type of airplane you can think of at an uncontrolled airport.

The cost of install between the skyBeacon and ESG/ESGi is significant. $180 for the skyBeacon and $1200 to $1500 for the ESGi. I don’t recommend doing the ESG even if you have a portable ADS-B in/AHRS device. For an extra $500 with the ESGi you get it all hardwired and out of sight.

A renter couldn’t mess with the skyBeacon as it’s password protected. Interestingly you can turn the Nav and strobe light off on the ground with the app. (Found that out the hard way.)

[[email protected]]

Thread drift warning :) I installed a Skybeacon on our 170B. It has a tow hook but with only the 0-300 in it we dont tow with it. I primarily use it for weekly commute to my property about 100 miles away.

It was by far the simplest install and the only cost is the 337 paperwork, and a friend IA did that for me. We arent planning on flying in controlled airspace or out of the country so couldn't justify the higher expense of 1080es and replacing the AT150 transponder. I know of many that have and are going the skybeacon route.

CH

[Ramy[_2_]]

I understand powerflarm does not detect UAT due to hardware limitation. It would be great if powerflarm would provide an upgrade path to receive UAT, giving that UAT seem to get more and more popular in USA GA thanks to skybeacon. Even an exchange program will do.

Ramy

[Mike Schumann[_2_]]

On Thursday, March 21, 2019 at 9:18:36 PM UTC-4, Ramy wrote:
> I understand powerflarm does not detect UAT due to hardware limitation. It would be great if powerflarm would provide an upgrade path to receive UAT, giving that UAT seem to get more and more popular in USA GA thanks to skybeacon. Even an exchange program will do.
>
> Ramy

The simplest option would be for PowerFlarm to utilize an off the shelf dual band ADS-B receiver like the pingUSB (https://uavionix.com/products/pingusb/) for the ADS-B IN capability and merge that data with the internally received FLARM information. The pingUSB sells for $175 and supports ADS-R and TIS-B.

[Bruce]

On Thursday, March 21, 2019 at 7:49:14 PM UTC-7, Mike Schumann wrote:
> On Thursday, March 21, 2019 at 9:18:36 PM UTC-4, Ramy wrote:
> > I understand powerflarm does not detect UAT due to hardware limitation. It would be great if powerflarm would provide an upgrade path to receive UAT, giving that UAT seem to get more and more popular in USA GA thanks to skybeacon. Even an exchange program will do.
> >
> > Ramy
>
> The simplest option would be for PowerFlarm to utilize an off the shelf dual band ADS-B receiver like the pingUSB (https://uavionix.com/products/pingusb/) for the ADS-B IN capability and merge that data with the internally received FLARM information. The pingUSB sells for $175 and supports ADS-R and TIS-B.

I have corresponded with Flarm and LX nav. Per the copied messages and still waiting for a reply from LX Navigation, The new OEM chip from Flarm support the things you are asking for. Flarm is not currently offering their own solution for consumers but may in the future. LX Nav is doing some of the support but not using the Flarm chip that does it all, so must have some proprietary implementation and don't appear to support TIS-R. LX Navigation is using Flarm's new chip but has been unresponsive to my inquiries.


My message to Flarm::
I live and fly in the USA. Are you planning to come out with a new product that incorporates your new oem chip with ADS-B, Mode-S, ADS-R and TIS-B receiver at 1090 MHz? and also the Mode C and S PCAS capabilities?

I have communicated with LX Nav and they indicated they are not implementing TIS-B. LX Navigation tells it's dealer here in the USA that they are implementing TIS-B and ADSB-R. But give no availability information. They have not responded to my inquiries.

Any insight you can provide me would be appreciated. I am currently using a PortableFlarm. but will need to give that up when I sell my old glider and would like to get the latest for the new(to me) motorglider.

Bruce

And their reply::

Hi Bruce

That's correct: LX Navigation has implemented the required hardware and will see support for TIS-R and ADS-R after the software upgrade, likely in summer 2019.

- Urban

Also in another message they indicated that they will not be supporting UAT..

Bruce BD

[Ramy[_2_]]

This sounds like an interesting possibility as the powerflarm core has a USB port. I’ll let Darryl analyze it...

Ramy

[JS[_5_]]

On Friday, March 22, 2019 at 12:44:48 AM UTC-7, Ramy wrote:
> This sounds like an interesting possibility as the powerflarm core has a USB port. I’ll let Darryl analyze it...
>
> Ramy

LXNav is waiting for FCC approval for the PowerMouse, which uses the new chip. Updates will probably come after that.
Jim

[kinsell]

On 3/22/19 1:44 AM, Ramy wrote:
> This sounds like an interesting possibility as the powerflarm core has a USB port. I’ll let Darryl analyze it...
>
> Ramy
>

The PingUSB just uses USB for power, data goes out over Wi-Fi, typically
to a tablet.

[Darryl Ramm]

On Friday, March 22, 2019 at 10:13:51 AM UTC-7, JS wrote:
> On Friday, March 22, 2019 at 12:44:48 AM UTC-7, Ramy wrote:
> > This sounds like an interesting possibility as the powerflarm core has a USB port. I’ll let Darryl analyze it...
> >
> > Ramy
>
> LXNav is waiting for FCC approval for the PowerMouse, which uses the new chip. Updates will probably come after that.
> Jim

I think it would be great to see ADS-R and maybe TIS-B support in FLARM devices.

FLARM has two chips and associated software currently available to OEMs, the actual FLARM chip and a new 1090ES In chip. The new 1090ES In chip is different than what is used in PowerFLARM.

Unfortunately (and this confused me in the past as well) the LXNav PowerMouse does *not* use the new FLARM 1090ES In developed chip, it uses their own developed technology in conjunction with the FLARM chip. The LX Navigation Eagle *does* use the new FLARM 1090ES In and FLARM chips.

I say unfortunately as this may create differences in how these otherwise similar products operate. I guess we'll have to wait and see. Personally I would rather all this technology came from FLARM and all OEM products operate identically. LXNav clearly makes great products so maybe they'll pull this off OK, buy I am concerned that their decision to roll their own stuff here may not have been the best decision.

This stuff is not as simple as "just support xyz protocol", there are for example going to be devil is in the details of different $PFLAU and $PFLAA FLARM warnings being generated for ADS-B direct, ADS-R and TIS-B traffic. There are also operational things that can help improve ease of use and safety that I'd hope vendors implement (from understandable documentation about what TIS-B and ADS-R support there is and the implications of that to say the receiver detecting and warning if the own-ship 1090ES Out does not exist or is not transmitting the capability code for 1090ES In).

A FLARM device comes with more than usual ADS-B In traffic receiver capabilities, the precise traffic warmings, relatively low false alarm rate, ability to operate on tow or in a gaggle etc. The positional accuracy of ADS-R and TIS-B is less than ADS-B Direct, or FLARM and in the case of TIS-B the positional error is much more. So adding extra ADS-R and TIS-B data comes with some challenges, not insurmountable, but this likely needs to be done with a good technical understanding of both the FLARM traffic algorithms, and understanding of how ADS-R and TIS-B works in practice in the USA.

I hope vendors have been testing this stuff in a realistic simulated USA ADS-B/TIS-B/ADS-R environment before any USA product release, and that they explain implications of what what they implement for ADS-R and especially TIS-B (if supported) to users. (Don't forget for reliable operation both ADS-R and TIS-B require your aircraft to have TABS or 2020 Compliant ADS-B Out).

BTW technical aside... be careful when talking about "TIS-B" especially in more technical conversations with vendors. TIS-B can refer to the relay of SSR data from ground stations over ADS-B as implemented in the USA today (as I used it above). But to a more technical person TIS-B may also mean the general data message format used for both that FAA TIS-B and ADS-R services, for example if an engineer is reading the RTCA DO-260B standard they would implement support for the TIS-B message format to receive ADS-R data and might talk about that as "TIS-B support".

[Darryl Ramm]

On Friday, March 22, 2019 at 11:04:34 AM UTC-7, kinsell wrote:
> On 3/22/19 1:44 AM, Ramy wrote:
> > This sounds like an interesting possibility as the powerflarm core has a USB port. I’ll let Darryl analyze it...
> >
> > Ramy
> >
>
> The PingUSB just uses USB for power, data goes out over Wi-Fi, typically
> to a tablet.

Right. And a third party MUX box that can receive that WiFi could merge it with FLARM serial data. But ah if the data is lower-resolution ADS-R or TIS-B targets does that MUX take it upon itself to generate FLARM $PFLAU target messages? Can it even tell what the source of the data is? Does it assign higher $PFLAU priority that FLARM targets? Does it rewrite existing FLARM generated $PFLAU messages? How does the behavior of those algorithms compare to FLARM's proprietary implementation? Does it only generate $PFLAA messages for this other traffic? That may be OK but what happens when a target gets close and the user does not get the high-priority FLARM warning they might otherwise expect? How will different FLARM displays handle any strangeness here?

Again it depends on what you are trying to achieve. The GDL-90 protocol serial data provided by most of these ADS-B out devices does not contain all the information you would want to build the most comprehensive integrated FLARM and ADS-B In system. You can provide coarse traffic information akin to what ADS-B In systems do today, and that may be fine but there are critters hiding below the surface of the swamp even there. It's possible to provide better integration if working on the "other side" of the interface, e.g. before the information is tuned into GDL-90 serial data, and that's a benefit of say the approach taken with the FLARM provided FLARM chipset and 1090ES receiver chip. That unfortunately does not get you UAT-direct. I just can't imagine there is a way for FLARM to invest time in UAT hardware for the small USA glider community.

I am glad some progress is being made but just want to caution not all this stuff is a simple as it might seem (Hi Andy :-)) . If it was we'd likely have stuff doing this today.

[Andy Blackburn[_3_]]

On Friday, March 22, 2019 at 3:07:18 PM UTC-5, Darryl Ramm wrote:
> On Friday, March 22, 2019 at 11:04:34 AM UTC-7, kinsell wrote:
> > On 3/22/19 1:44 AM, Ramy wrote:
> > > This sounds like an interesting possibility as the powerflarm core has a USB port. I’ll let Darryl analyze it...
> > >
> > > Ramy
> > >
> >
> > The PingUSB just uses USB for power, data goes out over Wi-Fi, typically
> > to a tablet.
>
> Right. And a third party MUX box that can receive that WiFi could merge it with FLARM serial data. But ah if the data is lower-resolution ADS-R or TIS-B targets does that MUX take it upon itself to generate FLARM $PFLAU target messages? Can it even tell what the source of the data is? Does it assign higher $PFLAU priority that FLARM targets? Does it rewrite existing FLARM generated $PFLAU messages? How does the behavior of those algorithms compare to FLARM's proprietary implementation? Does it only generate $PFLAA messages for this other traffic? That may be OK but what happens when a target gets close and the user does not get the high-priority FLARM warning they might otherwise expect? How will different FLARM displays handle any strangeness here?
>
> Again it depends on what you are trying to achieve. The GDL-90 protocol serial data provided by most of these ADS-B out devices does not contain all the information you would want to build the most comprehensive integrated FLARM and ADS-B In system. You can provide coarse traffic information akin to what ADS-B In systems do today, and that may be fine but there are critters hiding below the surface of the swamp even there. It's possible to provide better integration if working on the "other side" of the interface, e.g. before the information is tuned into GDL-90 serial data, and that's a benefit of say the approach taken with the FLARM provided FLARM chipset and 1090ES receiver chip. That unfortunately does not get you UAT-direct. I just can't imagine there is a way for FLARM to invest time in UAT hardware for the small USA glider community.
>
> I am glad some progress is being made but just want to caution not all this stuff is a simple as it might seem (Hi Andy :-)) . If it was we'd likely have stuff doing this today.

I was going to chime in since we built some Statux boxes (with a Ping USB receiver in my case which communicates with Stratux through the RPi USB port). All the problems Darryl describes are true. There is no way to de-duplicate and, depending on your setup and the traffic around you, a single UAT target may show up as 1090ES via ADS-R, TIS-B or UAT direct - all within a few seconds. Similar story for 1909ES targets. Other traffic with the other ADS-B Out physical layer can light up duplicate target for you. In addition, you have to roll your own alarms, which will be different from Flarm, because ADS-B delivers different data than Flarm so you may be stuck with simple proximity alarms (good luck writing your own mux software to de-duplicate Flarm native versus Flarm ADS-B versus Stratux/Ping ADS-R via UAT versus Stratux/Ping TIS-B 1090ES for the same aircraft (I demoed this mess for myself more than once) and God help you if that aircraft is your towplane. Also TIS-B resolution is only a mile or so depending on speed and distance from an SSR ground station plus network lag so you need a way to display it that shows you this imprecision.

At the time I spoke the Flarm guys about plugging PingUSB into the Flarm USB port since that's how it transmits data and would give you at least a fighting chance at integrating all the traffic types. It seemed like there were a lot of obstacles and I expect not the least of it is that the US only represents a few thousand units and it's a lot of custom code and may overwhelm the Flarm processor. I'm thankful they rolled a new OEM chipset that has the potential to support ADS-R and TIS-B. As long as you have ADS-B 1090ES Out that solves 99.9% of the scenarios anyone could care about. I wouldn't hold my breath for anything more. There's just no reason for them to accommodate UAT die-hards if ADS-R and TIS-B are more practical routes to getting the same job done.

Andy Blackburn
9B

[[email protected]]

> I think it would be great to see ADS-R and maybe TIS-B support in FLARM devices.

I had the same idea and made myself a hat with a ADS-B receiver for Raspberry Pi. The Pi is interconnected between the FLARM and the Butterfly display and the ADS-B information is added to the FLARM information.

My plan is to make it open source and open hardware, and provide PCB´s for those who are interested.

[Ramy[_2_]]

Bringing back this old thread.
So last year it seem that the ADS-B alarm suppression during tow was working well as I received only occasional short alarms.
However with most recent firmware and a new tow plane ADS-B installation I and others receiving constant alarm during the tow. Very distracting.
I don’t know if this is a regression in latest firmware or something wrong with the tow plane ADS-B.
I would like to know if others still experiencing ADS-B collision alarm during tow when towing behind ADS-B equipped tow plane.

Ramy

[George Haeh]

The PowerFLARM and ADS-B in the towplane have to have the same ICAO IDs (likely already done).

Without a PowerFLARM in the towplane, the glider PowerFLARM will see it as an ordinary power plane and can get worried.

Perhaps enrolling the towplane ICAO ID in FlarmNet will help the display logic. Won't hurt to try.

[Urban]

Hi Ramy

We're not aware of any regression. What firmware version are you using?

Sounds like the tow plane configuration is not consistent, either for the FLARM or the ADS-B transmitter. But that's me speculating.

Can you please send (IGC) log files to ?

Thanks
- Urban

[Ramy[_2_]]

Hi Urban,

I am using latest firmware 6.82.
Our tow plane has only ADS-B out, not flarm.
What configuration error in the tow plane could cause such issue?
I also exchanged emails with Daniel and will provide IGC file as soon as I get to my glider most likely next weekend.
Meanwhile I was hoping to hear from others if they still noticing false alarms during tow now that more and more tow planes in the US are equipped with ADS-B out.
I assume from the lack of response that folks no longer experiencing issues, or the season didn’t start yet for them to tell. Maybe the folks at Seminole can tell as their tow plane should be equipped with ADS-B out giving that they are in the Mode C veil.

Ramy

[George Haeh]

I am wondering if it would help to enroll the towplane ICAO ID in FlarmNet.

Of course the FlarmNet database is carried in the various traffic displays and flight computers, NOT in the Core.

[Ramy[_2_]]

In fact this is exactly what we did. I added the tow plane to flarmnet so we can easily recognize it. It works. I first suspected that maybe this caused the false alarm but then recalled that the powerflarm don’t know anything about the flarmnet database as the flarmnet is only used by the display, and as such could not impact the alarm suppression.

Ramy

[Urban]

Hi Ramy

Can't think of anything that's wrong here, 6.82 should suppress all ADS-B targets in the "right" relative position indicating a tow train. We'll have a look at the logs to figure it out.

As you mentioned correctly, FLARMNet does not influence alarming.

- Urban