Flarm collision alert from Tow Plane ADS-B

On Saturday, March 17, 2018 at 7:01:12 PM UTC-7, wrote:
On Friday, March 16, 2018 at 9:42:59 PM UTC, wrote:
Now that our club tow plane has installed ADS-B out, I’m getting a constant collision alert on my S80, Flarm butterfly and Qudie while on tow. Is there any way to silence the collision alarm while on tow without turning off ADS-B targets on Flarm all together. I like seeing ADS-B targets while flying in congested areas. It would be nice is there was a way to identify specific ADS-B IDs that should not be reported like tow planes. It’s bad enough to just see the Flarm collision alert screen with the red 12 o’clock the whole time on tow, but having the constant beeping is just too much to tolerate.



I don't know what the answer is, but masking all tow planes all the time is probably not a good one. "There have been a few collisions between tow planes and gliders, those are ones you really want to avoid."

Do you mean at crowded contests or a one off tow or a commercial site with concurrect tows, or what? And where?

One off tow at a commercial site, not crowded at all, is the one I'm thinking about. A few near misses at others. At any gliderport, tow planes and gliders operate in close proximity. Your chance of midair collision is higher with a two plane than anything else. That's what's flying around. Not just the one you are following on a rope.

https://app.ntsb.gov/pdfgenerator/Re...=HTML&IType=FA

Reading that accident report from Crazycreek soaring made me sad. A radio in the towplane should have easily prevented that accident. So simple and inexpensive too. When I flew at another major gliderport in southern California a few years ago I was really surprised when they told me don't do a radio check, the tug doesn't have a radio. That seemed so archaic to me. Why not? A simple radio call can sort out alot of small problems that can blossom into major problems.
Do any gliderports still operate without radios in the towplanes?

On a related note, what happens when two gliders in a gaggle have ADS-B-out (or TABS)?

Scenarios:

1. Both gliders have ADS-B-out and Powerflarm flavor of ADS-B-in. Does Powerflarm filter spurious ADS-B collision alerts?

2. Glider 1 has ADS-B-out, no Powerflarm, and non-Powerflarm ADS-B-in

Glider 2 has ADS-B-out and Powerflarm flavor ADS-B-in

Does Glider 1 get spurious ADS-B collision alerts?

3. Both gliders have ADS-B-out, no Powerflarm, and non-Powerflarm ADS-B-in

Do both gliders get spurious ADS-B collision alerts?

I'm having a similar problem with just a mode-c transponder in the towplane.. I'm not getting a 'collision' warning per se, but the S80 does indicate a xpndr equipped aircraft is in close proximity. The issue with this is that the display is simply locked out from all other functions during the entire tow. That is, there is no way to get your vario display back until after the tow and the aircraft exceeds the threat threshold. This 'problem' also occurs when flying close to xpdr equipped gliders. I had caught up to a friend that had a mode-c xpdr and we flew together for over an hour. During the whole time, the S80 displayed the xpdr traffic page and I couldn't navigate past it to see any other pages. I had to ask my friend to turn off his transponder while we were flying together. It would be nice if the instrument had an "acknowledge" feature where I could suppress the alert for some configurable period of time so I can get access to the rest of the vario features (similar to the way modern computers handle airspace warnings). I want to tell the computer... "I see the traffic, now go away for 5 minutes", but I don't want to turn it off permanently, however for obvious reasons.

Has anyone else experienced this and have a solution?

Sounds like submitting a "bug fix" to your MFR.
While they can think of lots of things, sometimes users bring up a worthwhile suggestion/fix.

Taken from a "beta boy" (field service) for a company. Service tried out things, we made suggestions to the programmer, sometimes we had to "prove a need", but he was great to work with.

YMMV.......

On Monday, March 19, 2018 at 9:49:09 AM UTC-7, Charlie M. (UH & 002 owner/pilot) wrote:
Sounds like submitting a "bug fix" to your MFR.
While they can think of lots of things, sometimes users bring up a worthwhile suggestion/fix.

Taken from a "beta boy" (field service) for a company. Service tried out things, we made suggestions to the programmer, sometimes we had to "prove a need", but he was great to work with.

YMMV.......

Yes please.

Turning off and on safety equipment is yet another distraction, and yet another thing to forget to do, and PowerFLARM should actually be very useful on tow. If the towplane is not PowerFLARM equipped then that towplane pilot is not getting warned about FLARM equipped gliders in the area, and so you want the glider pilot who does have PowerFLARM to be on the radio if needed to warn the towplane. Does the towplane have ADS-B In? If not then the PowerFLARM in the glider is also standing guard against 1090ES Out equipped GA aircraft the tow pilot may not see. Remember that triple fatality Cirrus and Towplane/glider middair in the Denver area? It is getting more and more likely now that a similar GA aircraft will have 1090ES Out. Turning off safety equipment is a last resort, lets start by checking first if there is something that could be setup better here, or if not then help FLARM reduce the problem.

If if has not been already can the OP here please submit a report to your PowerFLARM dealer and they can make sure that gets to FLARM support. Include in that all the relevant information you can, including: A clear description of exactly how/what/when the glider pilot sees an alarm (like in the original post above). An IGC log file from the PowerFLARM. The PowerFLARM config file from the glider. What local transponder if any is in the glider. Details of the transponder and ADS-B Out in the towplane (find all it's ADS-B out settings, esp. aircraft type, ICAO address etc.) and/or include a FAA ADS-B report for the towplane from here... https://adsbperformance.faa.gov/PAPRRequest.aspx. There are configuration things listed there that FLARM may want to know. (I'm assuming this is in the USA..).

On Monday, March 19, 2018 at 11:26:16 AM UTC-5, Dirk_PW wrote:
I'm having a similar problem with just a mode-c transponder in the towplane. I'm not getting a 'collision' warning per se, but the S80 does indicate a xpndr equipped aircraft is in close proximity. The issue with this is that the display is simply locked out from all other functions during the entire tow. That is, there is no way to get your vario display back until after the tow and the aircraft exceeds the threat threshold. This 'problem' also occurs when flying close to xpdr equipped gliders. I had caught up to a friend that had a mode-c xpdr and we flew together for over an hour. During the whole time, the S80 displayed the xpdr traffic page and I couldn't navigate past it to see any other pages. I had to ask my friend to turn off his transponder while we were flying together. It would be nice if the instrument had an "acknowledge" feature where I could suppress the alert for some configurable period of time so I can get access to the rest of the vario features (similar to the way modern computers handle airspace warnings). I want to tell the computer... "I see the traffic, now go away for 5 minutes", but I don't want to turn it off permanently, however for obvious reasons.

Has anyone else experienced this and have a solution?

The FARs require that all transponder equipped aircraft have their transponders turned on whenever they are airborne.

On Monday, March 19, 2018 at 3:52:28 PM UTC-5, Mike Schumann wrote:

The FARs require that all transponder equipped aircraft have their transponders turned on whenever they are airborne.

Actually, no; as Dan has pointed out, when aircraft are in formation (which is a specific case - not just a bunch of aircraft in the same area, like a gaggle), only the flight lead is supposed to have his transponder on; the rest are supposed to be in standby. In pre-Mode S days this was essential as multiple Mode 3s responding in the same area at the same time would overwhelm the SSR system at worst and trigger all sorts of collision alarms at best.

When the formation breaks up, the wingmen are then supposed to turn on their transponders. Releasing from tow is breaking up the tow formation, so...

This applies to all military and civilian formation flights.

Kirk
66

On Tuesday, March 20, 2018 at 7:10:48 AM UTC-7, kirk.stant wrote:
On Monday, March 19, 2018 at 3:52:28 PM UTC-5, Mike Schumann wrote:

The FARs require that all transponder equipped aircraft have their transponders turned on whenever they are airborne.

Actually, no; as Dan has pointed out, when aircraft are in formation (which is a specific case - not just a bunch of aircraft in the same area, like a gaggle), only the flight lead is supposed to have his transponder on; the rest are supposed to be in standby. In pre-Mode S days this was essential as multiple Mode 3s responding in the same area at the same time would overwhelm the SSR system at worst and trigger all sorts of collision alarms at best.

When the formation breaks up, the wingmen are then supposed to turn on their transponders. Releasing from tow is breaking up the tow formation, so....

This applies to all military and civilian formation flights.

Kirk
66

The technical need for the leader only squawking is partially folklore by now. Modern radar can decorelate multiple overlapping Mode C only targets, and absolutely see multiple Mode S targets. A direct result of the S for selective interrogation in the Mode S name. Wether an ATC controller might prefer to see one target for a formation flight, and not want to have spurious warnings on their display is a different question.

When I've asked Reno area NORCAL TRACON folks if they would want "formation flights" of gliders or GA aircraft to only squawk leader they said no.

ADS-B Out goes even further and targets will not "step on each other".

I would not be turning off any transponder or ADS-B Out systems unless specifically instructed to by ATC or you had a prior arrangement with them where it has been made clear they want this. And unsure, ask them.

On Tuesday, March 20, 2018 at 10:13:23 AM UTC-5, Darryl Ramm wrote:
On Tuesday, March 20, 2018 at 7:10:48 AM UTC-7, kirk.stant wrote:
On Monday, March 19, 2018 at 3:52:28 PM UTC-5, Mike Schumann wrote:

The FARs require that all transponder equipped aircraft have their transponders turned on whenever they are airborne.

Actually, no; as Dan has pointed out, when aircraft are in formation (which is a specific case - not just a bunch of aircraft in the same area, like a gaggle), only the flight lead is supposed to have his transponder on; the rest are supposed to be in standby. In pre-Mode S days this was essential as multiple Mode 3s responding in the same area at the same time would overwhelm the SSR system at worst and trigger all sorts of collision alarms at best.

When the formation breaks up, the wingmen are then supposed to turn on their transponders. Releasing from tow is breaking up the tow formation, so...

This applies to all military and civilian formation flights.

Kirk
66

The technical need for the leader only squawking is partially folklore by now. Modern radar can decorelate multiple overlapping Mode C only targets, and absolutely see multiple Mode S targets. A direct result of the S for selective interrogation in the Mode S name. Wether an ATC controller might prefer to see one target for a formation flight, and not want to have spurious warnings on their display is a different question.

When I've asked Reno area NORCAL TRACON folks if they would want "formation flights" of gliders or GA aircraft to only squawk leader they said no.

ADS-B Out goes even further and targets will not "step on each other".

I would not be turning off any transponder or ADS-B Out systems unless specifically instructed to by ATC or you had a prior arrangement with them where it has been made clear they want this. And unsure, ask them.

Understood - that's why I used the caveat "pre-Mode S". But the problem still applies if you have a Mode C backing up your ADS-B, right? And definitely still applies to most military jets until they all get updated to Mode S/ADS-B.

As usual, the devil is in the details - how many civilian flights or all-glider flight are really "formations"? Towing is about the only common (?) case, and that is not usually going very high or into congested airspace.

I seriously doubt ATW would want everyone in a 16-ship formation of RV-6s to have their Mode 3/C on!

Kirk