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-   -   FAA ADS-B Avionics System Check (https://vansairforce.net/community/showthread.php?t=113529)

dmaib 05-30-2014 01:00 PM

Quote:

Originally Posted by Brantel (Post 884217)
It looks like the OP works for the government.
http://www.linkedin.com/pub/james-marks/20/240/733
It also looks like if you request your report and if you are out of spec, you are not allowed to xmit.

Personally I wish I had never requested that report!


Like you I was shocked to see my report. I have had absolutely no reason to believe that my system was not working properly.


I have a GTN 650 GPS and GTX 23 ES xponder

I am not sure there is much we can do from our end on this.

Honestly I am not going to get too excited until I hear something from the fine Garmin folks.

I read 91.225 and I am pretty sure the prohibition on transmitting is after Jan. 1, 2020.

Mike S 05-30-2014 01:04 PM

Brian, thanks for the Linkedin link-----------he seems to be with the FAA, ADS-B program as I suspected, and asked in my welcome post.

He has been watching this thread now for almost a half hour or possibly more, yet has not responded.........................too bad, I was hoping for someone in the program who was going to be active in supporting us in getting straight answers, and guidance through the ADS-B maze.

We shall see...........................................

Bavafa 05-30-2014 01:05 PM

Quote:

Originally Posted by Brantel (Post 884201)
Go here for a description of what those are and what the limits are for each item:

http://rgl.faa.gov/Regulatory_and_Gu...7!OpenDocument

Look at the "Distributions" section to see what your system is sending.

Here is my distribution and if I am reading this right, the entire duration of the flight "processed" which is reported as 10480, I have accuracy of greater than 10NM. Since I was using my GPS on an IFR flight plan, I would have thought to been made aware of this inaccuracy so I hardly think of such possibility.
Question is, how does the system determines my position to determine inaccurate reporting by me?
Perhaps what GPS is reporting (pertaining to ADS-B) is inaccurate and I am wondering if that is a setup issue.



Distribution by bavafa1, on Flickr

Brantel 05-30-2014 01:07 PM

Quote:

Originally Posted by dmaib (Post 884224)
I read 91.225 and I am pretty sure the prohibition on transmitting is after Jan. 1, 2020.

From the second document they sent:


Brantel 05-30-2014 01:13 PM

Quote:

Originally Posted by Bavafa (Post 884228)
Here is my distribution and if I am reading this right, the entire duration of the flight "processed" which is reported as 10480, I have accuracy of greater than 10NM. Since I was using my GPS on an IFR flight plan, I would have thought to been made aware of this inaccuracy so I hardly think of such possibility.
Question is, how does the system determines my position to determine inaccurate reporting by me?
Perhaps what GPS is reporting (pertaining to ADS-B) is inaccurate and I am wondering if that is a setup issue.



Distribution by bavafa1, on Flickr

What is your "GPS Position Integrity" level set to on your xponder?

Mine is set to "1E-5" and that results in a SIL of 2 but a SIL of 3 is required to be compliant.

Not sure if this will throw the other values out of whack or not but Garmin has informed me that the GNS/GTN series can legally and should be set to "1E-7".

I am going to try that and then request another report....

rleffler 05-30-2014 01:28 PM

Quote:

Originally Posted by Bavafa (Post 884228)
Here is my distribution and if I am reading this right, the entire duration of the flight "processed" which is reported as 10480, I have accuracy of greater than 10NM. Since I was using my GPS on an IFR flight plan, I would have thought to been made aware of this inaccuracy so I hardly think of such possibility.
Question is, how does the system determines my position to determine inaccurate reporting by me?
Perhaps what GPS is reporting (pertaining to ADS-B) is inaccurate and I am wondering if that is a setup issue.

My GTN650 is providing coordinates to the Navworx unit.

My report shows NIC <7.5m, NACp <10m, NACv <1m/s, SIL 10-7, SDA 10-5, GVA <45m

That was the same question that immediately came to mind. What other data source is being used to determine accuracy? Radar versus GPS position? This certainly has got me curious.

rleffler 05-30-2014 01:29 PM

Quote:

Originally Posted by jdm117 (Post 884156)
Want to know how your ADS-B system is performing? Send an email with N-number to 9-AWA-AFS-300-ADSB-AvionicsCheck@faa.gov and request a detailed report.

Thanks for making this available.

bob

jdm117 05-30-2014 01:31 PM

Hi Mike/All, Sorry for the delay in responding to your question regarding my association with the FAA's ADS-B program, I've been somewhat busy sending out ADS-B reports since my original post. Yes, I work on the FAA ADS-B program as a avionics safety inspector with Flight Standards in DC. My primary responsibilities are to develop policy, guidance & training related §91.225 & §91.227 for our avionics inspectors. I also provide outreach to the aviation community related to the installation & maintenance of ADS-B systems. My arrival to the Vans forum was spurred by the latter of these and the knowledge that many who have already equipped with ADS-B are unaware that the system is not working properly. I've had little success with the alphabet groups when seeking to publish material that would be helpful to members such as those here. So out of frustration thought I'd go VFR direct (so to speak) to a large group of the GA community and provide assistance as able.

dmaib 05-30-2014 01:42 PM

Quote:

Originally Posted by Bavafa (Post 884228)
Here is my distribution and if I am reading this right, the entire duration of the flight "processed" which is reported as 10480, I have accuracy of greater than 10NM. Since I was using my GPS on an IFR flight plan, I would have thought to been made aware of this inaccuracy so I hardly think of such possibility.
Question is, how does the system determines my position to determine inaccurate reporting by me?
Perhaps what GPS is reporting (pertaining to ADS-B) is inaccurate and I am wondering if that is a setup issue.



Distribution by bavafa1, on Flickr

I wondered about this, too. Since my flight was VFR with no flight plan and no ATC involvement other than the KEVB tower, I am wondering if this is showing that they have no way of knowing if my reported position is accurate?

Mike S 05-30-2014 01:43 PM

Quote:

Originally Posted by jdm117 (Post 884238)
I also provide outreach to the aviation community related to the installation & maintenance of ADS-B systems.

This is what I suspected, and hoped for when I asked the question in the first place.

You have come to the right place for sure---------the level of electronic sophistication on many of the RVs flying is a ripe test bed for you to interact with.

Very good to have you aboard:D


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