Missing ADS-B TFR data in Seattle Area

[PT20J]

I have been receiving incomplete FIS-B NOTAM-TFR data for some time in the Seattle WA area and wonder if anyone else has noticed the same thing.

My GTX 345 feeds my GTN 650Xi which isn't depicting numerous nearby firefighting TFRs on the map and the timestamp says TFR: No Data.

I circled at 6000' AGL and about 25 nm from the Ground Based Transceiver (GBT) tower at KPAE for half an hour and never received complete data. The radio station page on the GTN showed the following: 

I was getting TFRs depicted on ForeFlight which is Bluetooth paired to the GTX. However, I learned from ForeFlight support that ForeFlight caches TFR data from a previous Internet connection and there is no way to determine whether the TFR data is current ADS-B In data or previously cached. There is no way to clear the cache.

I called the L3Harris SBSS Network Operations Center which operates the ADS-B ground system under contract to the FAA. They don't monitor the actual FIS-B data being transmitted. They have no open tickets for issues in the Seattle WA area except for some periodic outages due to solar flares that should end today. The GBTs are pretty dumb -- they just transmit what they get from the data source. If some TFR data were missing from the source data it would explain why I did not get complete TFR data even when I climbed high enough to receive multiple GBTs.

Garmin can't see a problem with their equipment and right now I'm thinking that the issue may be that the source data is incomplete. 

Has anyone else noticed this issue in the Seattle area?

Skip

[gacoon]

I fly in the area also, havent seen that one and will watch for it.  We do see a lot of traffic ghosting when flying  West of SEA in the Vashon Island area.  Manifests itself as a traffic target at same altitude and very close.  Never see it elsewhere.

[Ragsf15e]

15 hours ago, PT20J said:

I have been receiving incomplete FIS-B NOTAM-TFR data for some time in the Seattle WA area and wonder if anyone else has noticed the same thing.

My GTX 345 feeds my GTN 650Xi which isn't depicting numerous nearby firefighting TFRs on the map and the timestamp says TFR: No Data.

I circled at 6000' AGL and about 25 nm from the Ground Based Transceiver (GBT) tower at KPAE for half an hour and never received complete data. The radio station page on the GTN showed the following: 

I was getting TFRs depicted on ForeFlight which is Bluetooth paired to the GTX. However, I learned from ForeFlight support that ForeFlight caches TFR data from a previous Internet connection and there is no way to determine whether the TFR data is current ADS-B In data or previously cached. There is no way to clear the cache.

I called the L3Harris SBSS Network Operations Center which operates the ADS-B ground system under contract to the FAA. They don't monitor the actual FIS-B data being transmitted. They have no open tickets for issues in the Seattle WA area except for some periodic outages due to solar flares that should end today. The GBTs are pretty dumb -- they just transmit what they get from the data source. If some TFR data were missing from the source data it would explain why I did not get complete TFR data even when I climbed high enough to receive multiple GBTs.

Garmin can't see a problem with their equipment and right now I'm thinking that the issue may be that the source data is incomplete. 

Has anyone else noticed this issue in the Seattle area?

Skip

I flew to Seattle and portland this week and there were no tfrs depicted on my g1000.  It isn’t ADSB though… it’s XM.  They are normally there, and I checked the status page and it showed green/good.  Weird.

[PT20J]

There are currently 7 TFRs in Washington state according to tfr.faa.gov. All are depicted on ForeFlight with an internet connection. I didn’t get any of them on ADS-B. I wonder where the ForeFlight, ADS-B and XM data comes from?

[Ragsf15e]

7 minutes ago, PT20J said:

There are currently 7 TFRs in Washington state according to tfr.faa.gov. All are depicted on ForeFlight with an internet connection. I didn’t get any of them on ADS-B. I wonder where the ForeFlight, ADS-B and XM data comes from?

Be funny if you were the one to figure out that this wasn’t Working for the FAA.  You should send them a bill for your time.

[PT20J]

28 minutes ago, Ragsf15e said:

I flew to Seattle and portland this week and there were no tfrs depicted on my g1000.  It isn’t ADSB though… it’s XM.  They are normally there, and I checked the status page and it showed green/good.  Weird.

On the GTN 650Xi, the datalink status shows NOTAM-TFR as green which means “data available.” But, the radio stations status shows NOTAM-TFR “incomplete”, and the timestamp on the map shows “TFR: No data.” So, it seems like the GTN is receiving incomplete data and won’t display anything until it has a complete data set.

Skip

[Ragsf15e]

On 10/20/2022 at 8:24 AM, PT20J said:

On the GTN 650Xi, the datalink status shows NOTAM-TFR as green which means “data available.” But, the radio stations status shows NOTAM-TFR “incomplete”, and the timestamp on the map shows “TFR: No data.” So, it seems like the GTN is receiving incomplete data and won’t display anything until it has a complete data set.

Skip

There’s a firefighting tfr near astoria that is showing on g1000 with xm. How about your system?

[PT20J]

Rats, it was gone before I could check. Must have just been somebody's barbeque 

I'm getting closer to understanding what's going on. It seems that the GTN is receiving all textual NOTAM-TFRs, but some graphic TFRs aren't being  depicted on the map. I asked the FAA ADS-B team some questions and they provided a link to a lengthy technical document that I am still deciphering. 

One interesting thing is that the Garmin GTN 650Xi iPad simulator, and the GTN User Guide, both show the GTN graphically depicting TFRs around stadiums on the map. However, I've never seen them on the GTN. ForeFlight does show them, but FF tech support tells me that these do not come from the FAA but instead from another source. The FAA ADS-B document says that the source of FIS-B TFRs is tfr.faa.gov which does not show sporting event TFRs for stadiums -- only airshows.

So I await more fires or VIP visits to pop up TFRs for further testing.

Skip

P.S. For anyone interested in the technical details, here's the info I got from adsb@faa.gov:

... SBS Description Document, which is posted on the FAA’s Dynamic Regulatory System (DRS), and within the attachments folder for TSO-C195b.  You should follow this link (https://drs.faa.gov/browse/excelExternalWindow/45845CD583AD3CD686257D62006B3B3E.0001), select the “Attachments/Public Comments” tab on the left bar and download the SDD pdf file.

[EricJ]

29 minutes ago, PT20J said:

Rats, it was gone before I could check. Must have just been somebody's barbeque 

I'm getting closer to understanding what's going on. It seems that the GTN is receiving all textual NOTAM-TFRs, but some graphic TFRs aren't being  depicted on the map. I asked the FAA ADS-B team some questions and they provided a link to a lengthy technical document that I am still deciphering. 

One interesting thing is that the Garmin GTN 650Xi iPad simulator, and the GTN User Guide, both show the GTN graphically depicting TFRs around stadiums on the map. However, I've never seen them on the GTN. ForeFlight does show them, but FF tech support tells me that these do not come from the FAA but instead from another source. The FAA ADS-B document says that the source of FIS-B TFRs is tfr.faa.gov which does not show sporting event TFRs for stadiums -- only airshows.

So I await more fires or VIP visits to pop up TFRs for further testing.

Skip

P.S. For anyone interested in the technical details, here's the info I got from adsb@faa.gov:

... SBS Description Document, which is posted on the FAA’s Dynamic Regulatory System (DRS), and within the attachments folder for TSO-C195b.  You should follow this link (https://drs.faa.gov/browse/excelExternalWindow/45845CD583AD3CD686257D62006B3B3E.0001), select the “Attachments/Public Comments” tab on the left bar and download the SDD pdf file.

This came up on the Avare forum a while back, that Avare generally shows TFRs very well, but not stadium TFRs.   The developers explained that they didn't support that because the document that defines the data formats costs $360, which is apparently too high of a barrier  (rolleyes emoji goes here).   

https://my.rtca.org/productdetails?id=a1B1R000009LguVUAS