Case Study Near Mid Air Glider and C421 - Benefits of PowerFlarm and Transponders

The speed at which gliders typically fly is less than the normal filter for radar tracking. If you don't have a transponder, it is unlikely that they will be able to pick you up.

Walt, thanks for the great info, and thanks for following up with this with he FAA. That radar tape is frustrating to watch. Mr. Golden Eagle maybe ought to be investing in some ADS-B Out/In (and/or TCAS/TCAD) technology.

On Tuesday, January 19, 2016 at 11:09:34 PM UTC-8, WaltWX wrote:

When you listen to the audio/video you will see a red "CA" meaning Conflict Alert going off for the controller. This went off at 33 seconds. If FAA modified their ADS-B ERAM software, they could send out ADS-B packets for aircraft on a collision course. PowerFlarm would then have given plenty of warning without cluttering the bandwidth of ADS-B with unnecessary information. This recommendation was made to the FSDO FAA representative who interviewed me.

I'm not sure the PowerFLARM would receive this, if it is a TIS-B style message, my understanding is it would not. But yes ideally for lots of reasons the FAA would have thought all this through a decade ago and just broadcast blind TIS-B transponder traffic conflicts like this on both ADS-B links. That would likely be a useful safety improvement for lots of GA traffic.... I would hope not, but I do would not be totally surprised in the past if some factions within the FAA may have been concerned about doing that as it decreases incentives for traffic to equip with complaint ADS-B Out.

I know lots of the glider pilots who fly in your area are fantastic at working working with ATC, Joshua Approach etc. One thing that listening to that tape that maybe shows is the benefit of having a airband radio with channel monitoring listening to ATC. Now overall is that distraction worth it? Maybe, maybe not. In some hotspots I'm sure it is. If I was buying a radio now, that feature be on my want-list.

A local SF bay Area hot-spot for GA traffic is near Travis AFB where there are lots of GA traffic exiting under the SFO Class B. Travis Approach/RAPCON are usually great to work with. Listening to them give traffic advisories about gliders etc. is eye opening. There is just a lot of frigging traffic there. And they may be totally blind to any non-transponder equipped traffic (because of doppler noise from lots of wind farms near Travis AFB). and calling 'em up and requesting flight following for gliders. Oh yes and lots of USAF C-5 Galaxies flying around (all with TCAS II.. so definitely transponder material).

On Wednesday, January 20, 2016 at 11:10:13 AM UTC-8, Darryl Ramm wrote:



I'm not sure the PowerFLARM would receive this, if it is a TIS-B style message, my understanding is it would not. But yes ideally for lots of reasons the FAA would have thought all this through a decade ago and just broadcast blind TIS-B transponder traffic conflicts like this on both ADS-B links. That would likely be a useful safety improvement for lots of GA traffic..... I would hope not, but I do would not be totally surprised in the past if some factions within the FAA may have been concerned about doing that as it decreases incentives for traffic to equip with complaint ADS-B Out.

One argument for equipping glider with a transponder and/or ADS-B for all it's cost... would be that we get something in return... namely Collision Advisory "CA" alerts like the controllers get. Your probably right, it would likely come in the form of a TIS-B packet which is not detected by PowerFlarm at this time on both ADS-B channels. By only doing it for "CA"'s, bandwidth would not be an issue. Do you think the PowerFlarm people could easily add TIB-B and ADS-R packets?


I know lots of the glider pilots who fly in your area are fantastic at working working with ATC, Joshua Approach etc. One thing that listening to that tape that maybe shows is the benefit of having a airband radio with channel monitoring listening to ATC. Now overall is that distraction worth it? Maybe, maybe not. In some hotspots I'm sure it is. If I was buying a radio now, that feature be on my want-list.


Monitoring of local ARTCC or Approach frequencies for traffic, I've found is not worth the trouble. You know something fast and big is in the area, but do not have any idea where... just like receiving PCAS alerts.

Walt Rogers

On Wednesday, January 20, 2016 at 6:50:09 PM UTC-5, WaltWX wrote:

Monitoring of local ARTCC or Approach frequencies for traffic, I've found is not worth the trouble.

So you did not hear ATC communicating with the C421 about the conflict? Was there any way for ATC to contact you by radio?

On Thursday, January 21, 2016 at 9:00:49 AM UTC-8, son_of_flubber wrote:
On Wednesday, January 20, 2016 at 6:50:09 PM UTC-5, WaltWX wrote:

Monitoring of local ARTCC or Approach frequencies for traffic, I've found is not worth the trouble.

So you did not hear ATC communicating with the C421 about the conflict? Was there any way for ATC to contact you by radio?

I was not monitoring ATC frequency. It was in ARTCC airspace and the frequency was not obvious unless you have an IFR map or are "in the system". There was another glider a mile or two away with a transponder, so ... I suppose it would have alerted me to increase my scanning for traffic. But, there is no way to know which direction to look and that is the basis for my original comment that monitoring ATC frequencies doesn't help that much for collision awareness. I was just lucky that my scanning caught the C421 while in a right turn, but the PowerFlarm PCAS went off a second or two later.

Walt Rogers

Yes, I heard them. IIRC, they informed the 421 of the presence of the
glider but gave no vector for spacing. I'm assuming the 421 was on an
IFR flight plan and therefore had to maintain his assigned heading. Of
course, he could have asked for a vector to avoid traffic. I've done
that many times. He did not, or at least I did not hear it.

On 1/21/2016 10:00 AM, son_of_flubber wrote:
On Wednesday, January 20, 2016 at 6:50:09 PM UTC-5, WaltWX wrote:

Monitoring of local ARTCC or Approach frequencies for traffic, I've found is not worth the trouble.
So you did not hear ATC communicating with the C421 about the conflict? Was there any way for ATC to contact you by radio?

--
Dan, 5J

On Thursday, January 21, 2016 at 2:20:33 PM UTC-5, Dan Marotta wrote:
... I'm assuming the 421 was
on an IFR flight plan and therefore had to maintain his assigned
heading.* Of course, he could have asked for a vector to avoid
traffic.*

IRRC ATC is not tasked to maintain IFR to VFR separation (?) (only IFR to IFR). So according to protocol, was ATC waiting for 421 to request vector to avoid traffic?

(I really have no idea what I'm talking about, but I'd like to understand this scenario.)

Thanks, Walt.
With transponder and on ATC frequency you will hear other pilots being warned of your position relative to theirs, just as the 421 in this case. Typically "traffic, a glider, (distance, relative direction, altitude), maneuvering". Personally haven't heard detail on climb, whether rate or just "climbing".
Flying with another glider, each using discrete codes ATC has not issued maneuvering instructions in my experience. Perhaps just "do you see the other glider?"
The controller would assume an aicraft squawking VFR was on another frequency.
Even before the 1201 then 1202 VFR codes, controllers could tell a glider squawking 1200 from other aircraft. A fiberglass glider without transponder could be invisible to radar.
If something like this happens to you, it's possible to submit a NASA form which is supposed to be anonymous and used to help prevent future occurrences.
Jim

That was very good watching, Walt. I wonder why the ATC controller did
not give the 421 a slight turn rather than simply issuing a warning of a
conflict. This also shows that it's not a bad idea to monitor Approach
and Departure frequencies when you're in or near standard routes. Glad
there was nothing more than some unnecessary excitement!

On 1/20/2016 12:09 AM, WaltWX wrote:
With all the discussion about FLARM, ADS-B and the Pros/Cons, I thought the time is right to bring some facts into the discussion. Last September I had a near mid air with a C421. Since I had recently equipped over the previous winter with a Mode S transponder (Trig T22), I was curious whether: 1) It was working... 2)Did the FAA use my target to call traffic.

Turned out the answer was yes! to both questions. I filed a near mid report to the FAA which resulted in two interviews and this radar ARTCC video with ATC controller audio. I think you'll find it quite interesting.

https://dl.dropbox.com/s/k8ph9wogyif...1 TT.wmv?dl=0

The FAA statement incorrectly identified the twin as a King Air with only (my visual esimate)
horizontal separation estimate of 500ft.

https://dl.dropbox.com/s/e6gvhn6dybx...FAA.pdf?dl =0

According to the radar we passed by at 10,000msl zero vertical and 1300ft horizontal. By pure luck and good scanning technique, I sighted the C421 15 seconds before crossing. PowerFlarm PCAS went off 2-3 seconds later. PowerFlarm would have got my attention if my visual scanning had failed me. No evasive action occurred on my part.

When you listen to the audio/video you will see a red "CA" meaning Conflict Alert going off for the controller. This went off at 33 seconds. If FAA modified their ADS-B ERAM software, they could send out ADS-B packets for aircraft on a collision course. PowerFlarm would then have given plenty of warning without cluttering the bandwidth of ADS-B with unnecessary information. This recommendation was made to the FSDO FAA representative who interviewed me.

I am complete agreement with Darryl Ramm's analysis of this whole transponder (Mode S) PowerFlarm recommendation. They complement each other quite well... and this is the best solution for the time being. As he has said, the whole ADS-B thing with TABS looming in the near future is in a state of flux. I wouldn't be surprised to see combined Mode-S/ADS-B transponders coming onto the market in abundance within 3 or 4 years.

In case you are wondering ... I did NOT recommend in my response to the FAA NPRM immediately equipage of gliders with transponders. Instead, utilize good airspace practices, training and a short "wait and see" for more affordable equipment to become available. However, if you have the money... by all means equip with a transponder and PowerFlarm.

Walter Rogers "WX" Discus 2A

--
Dan, 5J

Well there are good controllers and not so good. I have had many very close calls, while flying under flight following, IFR plan, or under the Tower's control. Four of my nearest (one within inches) happened within several hundred or less feet of actually taking off, and still over the runway. Burbank, Santa Barbra (twice), and El Cajon. The one in Burbank also involved an United Airlines MD80, in Santa Barbra the control tower actually was ****ed off at the C414 pilot that loudly complained he had to take sudden low altitude evasive manouvers (we both did!) and go around because the control tower had directed me (departing in a helicopter) nose to nose with the C414 on short final. To this day I can hear the controller with a very annoyed tone, "yeah just go around, cleared to land..."

Another time flying a C340 through the Owens valley on flight following, Joshua approach in a harried/worried tone informed me that two F/A-18's were converging on my position from behind, then he asked if I had the traffic. Told him I did not have much rear visibility. He then told me in a worried tone "they are approaching fast!" I asked him for a course to deviated, it was like he had never thought of that! I do not include this as a near miss, I have had so many. Some you cannot control like the AS---le that flew underneath me (i could see him via Mode S traffic display on my HSI/map/traffic instrument) and as he dove to go under I turned 90 degrees only to see him zoom up where I had been. I think this fool was trying to fly under me then scare me by zooming up from underneath, however, had I not turned, he would have hit me as he did not have vision above. I am in full support of anything that gives me the most situational awareness as possible!

Perhaps a better use of Flarm resources rather than to develop a stealth mode would be to certify the Flarm GPS for use with trig and garrecht transponders that have ADS-B out and then output the data so our computers will display all traffic from any acronym source. I already have three GPS' I am hoping I will not have to buy a fourth to get ADS-B.

On Wednesday, January 20, 2016 at 3:40:47 PM UTC-8, Dan Marotta wrote:
That was very good watching, Walt.* I wonder why the ATC controller
did not give the 421 a slight turn rather than simply issuing a
warning of a conflict.* This also shows that it's not a bad idea to
monitor Approach and Departure frequencies when you're in or near
standard routes.* Glad there was nothing more than some unnecessary
excitement!




On 1/20/2016 12:09 AM, WaltWX wrote:



With all the discussion about FLARM, ADS-B and the Pros/Cons, I thought the time is right to bring some facts into the discussion. Last September I had a near mid air with a C421. Since I had recently equipped over the previous winter with a Mode S transponder (Trig T22), I was curious whether: 1) It was working... 2)Did the FAA use my target to call traffic.

Turned out the answer was yes! to both questions. I filed a near mid report to the FAA which resulted in two interviews and this radar ARTCC video with ATC controller audio. I think you'll find it quite interesting.

https://dl.dropbox.com/s/k8ph9wogyif...1 TT.wmv?dl=0

The FAA statement incorrectly identified the twin as a King Air with only (my visual esimate)
horizontal separation estimate of 500ft.

https://dl.dropbox.com/s/e6gvhn6dybx...FAA.pdf?dl =0

According to the radar we passed by at 10,000msl zero vertical and 1300ft horizontal. By pure luck and good scanning technique, I sighted the C421 15 seconds before crossing. PowerFlarm PCAS went off 2-3 seconds later. PowerFlarm would have got my attention if my visual scanning had failed me. No evasive action occurred on my part.

When you listen to the audio/video you will see a red "CA" meaning Conflict Alert going off for the controller. This went off at 33 seconds. If FAA modified their ADS-B ERAM software, they could send out ADS-B packets for aircraft on a collision course. PowerFlarm would then have given plenty of warning without cluttering the bandwidth of ADS-B with unnecessary information. This recommendation was made to the FSDO FAA representative who interviewed me.

I am complete agreement with Darryl Ramm's analysis of this whole transponder (Mode S) PowerFlarm recommendation. They complement each other quite well... and this is the best solution for the time being. As he has said, the whole ADS-B thing with TABS looming in the near future is in a state of flux. I wouldn't be surprised to see combined Mode-S/ADS-B transponders coming onto the market in abundance within 3 or 4 years.

In case you are wondering ... I did NOT recommend in my response to the FAA NPRM immediately equipage of gliders with transponders. Instead, utilize good airspace practices, training and a short "wait and see" for more affordable equipment to become available. However, if you have the money... by all means equip with a transponder and PowerFlarm.

Walter Rogers "WX" Discus 2A





--

Dan, 5J