Ads-b hell

[Taracka]

About a month ago, I installed a Uavionix Skybeacon on my M20C.  Initially there was an issue with the Transponder monitor threshold needing adjustment to work with my Narco AT 150 transponder.  After 4 test flights I got that worked out, passed, and got the rebate.  About a week ago, I received a certified letter from Mike Smith at the FAA in Washington DC stating my ads-b failed to comply with equipment performance requirements and I had 45 days to fix it or the airplane would be subject to filter which prevents processing of ads-b data.  After speaking with Uavionix tech support, they feel the problem is fringe area poor reception.  The FAA guy says it’s the device configured improperly. The Skybeacon has short duration “mode 3A” failures which seems to be consistent with being at low altitude where my transponder isn’t being interrogated and thus not sending out a squawk code for the Skybeacon to see.  I’m stuck in the middle of this and am considering returning the Skybeacon and going with another option since I have spent tons of time on this and most of my rebate on fuel.  Has anyone on here had a similar problem?

Rich

[1964-M20E]

I got the same registered letter on my Avidyne remote mounted transponder AXP-322.  I have had it installed for over 3 years now.

I talked with the guy on my letter Friday evening and will discuss with him more on Monday.  Hopefully he can tell me exactly what is wrong.  FLIGHT AWARE still tracks every flight I make and sends me an email every time I land and I can se every flight I have made.

sorry had wrong site

I hope ADSB does not continue to act like this.  In all the years I have been flying I only had one issue with Mode C when a wire broke going to the altitude encoder.

 

 

[carusoam]

Gents... if able, can you post the pertinent parts of the letters...

I find it hard to believe the FAA has enough time and tech support to write specific things that are wrong with your systems, from so far away...

There must be thousands of similar systems acting the same way... The FAA has a handful(?) of people to do work like this.

This would be the same FAA that can’t process standard medical documents in a year’s time... before the data expires...

There are certain things that the FAA is staffed to do each day... specialty projects can’t possibly be their bailiwick...

 

Expect that we can collect a few similar letters, and share with AOPA...get some guidance where the system is broken... or find some collective technical solutions if we have broken technical set ups....

 

A system that is this hard to comply with... isn’t a very valuable system...

 

From the opposite end of the spectrum and prior experience...  It will be hard to get flight following if your Mode C goes down....  the FAA doesn't send letters for that...  

PP thoughts only, not a tech writer or lawyer...

Best regards,

-a-

[MooneyMitch]

Looking forward to this topic discussion!!!!

[Marauder]

Gents... if able, can you post the pertinent parts of the letters...
I find it hard to believe the FAA has enough time and tech support to write specific things that are wrong with your systems, from so far away...
There must be thousands of similar systems acting the same way... The FAA has a handful(?) of people to do work like this.
This would be the same FAA that can’t process standard medical documents in a year’s time... before the data expires...
There are certain things that the FAA is staffed to do each day... specialty projects can’t possibly be their bailiwick...
 
Expect that we can collect a few similar letters, and share with AOPA...get some guidance where the system is broken... or find some collective technical solutions if we have broken technical set ups....
 
A system that is this hard to comply with... isn’t a very valuable system...
 
From the opposite end of the spectrum and prior experience...  It will be hard to get flight following if your Mode C goes down....  the FAA doesn't send letters for that...  
PP thoughts only, not a tech writer or lawyer...
Best regards,
-a-

We’re in a different world with ADS-B. The test protocols that we can do should tell us the health status of every flight that our ADS-B solution populates when in the system.

I would use the FAA site to look at previous flights to see which ones failed and the reason they failed.

https://adsbperformance.faa.gov/paprrequest.aspx

This should help both Avionix and your aviation shop understand what failed.


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[LANCECASPER]

4 hours ago, Taracka said:

About a month ago, I installed a Uavionix Skybeacon on my M20C.  Initially there was an issue with the Transponder monitor threshold needing adjustment to work with my Narco AT 150 transponder.  After 4 test flights I got that worked out, passed, and got the rebate.  About a week ago, I received a certified letter from Mike Smith at the FAA in Washington DC stating my ads-b failed to comply with equipment performance requirements and I had 45 days to fix it or the airplane would be subject to filter which prevents processing of ads-b data.  After speaking with Uavionix tech support, they feel the problem is fringe area poor reception.  The FAA guy says it’s the device configured improperly. The Skybeacon has short duration “mode 3A” failures which seems to be consistent with being at low altitude where my transponder isn’t being interrogated and thus not sending out a squawk code for the Skybeacon to see.  I’m stuck in the middle of this and am considering returning the Skybeacon and going with another option since I have spent tons of time on this and most of my rebate on fuel.  Has anyone on here had a similar problem?

Rich

If I had to guess I would say the problem is with your legacy Narco 150 Transponder.

The best all around deal out there for ads-b-out on legacy airplanes seems to be the GTX-335 with GPS that's approved for your mechanic to install ($2995). You get a new solid state transponder and 1090 in case you ever go into the flight levels or outside of the U. S.  

Using one of the UAT gizmos with an older cavity tube transponder is just kicking the can down the road. It's going to eventually need to be replaced.

I ended up with the GTX-345 and really like it.

[Cruiser]

what Lancecasper said..................^^^^^

Most of these combinations require a power output test, did your shop do one?

If you are not ready for that yet you can try replacing the existing antenna cable and antenna with new. RG400 cable and a new blade antenna might help. It will be required if you upgrade the transponder so it really is not a waste of money. It might help.

You can search eBay for a replacement, they are really cheap, but no guarantees it will work better. Check with the avionics shop for compatible units maybe something else, but I don't think there are any.

 

[1964-M20E]

Yeah if ADSB system is a PIA like this it will not be very usable.

 

Here are a few of the ADSB reports for the FAA site.  Any body who can tell me what is going on it would be appreciated.  I will be calling the FAA guy Monday as well to discuss this further.

I'm an engineer but ADSB is FM technology to me and the reports are not very intuitive.

 

Then a buddy was flying my plane today and ATC said mode C was not reporting altitude. 

 

PAPR_20190224_A856D6_70570220.pdfPAPR_20190312_A856D6_71437905.pdfPAPR_20190317_A856D6_71704303.pdf

[Cruiser]

SDA failure mean you do not have a valid GPS source.

This could be a configuration setting or an actual signal failure 

[Yetti]

6 hours ago, LANCECASPER said:

If I had to guess I would say the problem is with your legacy Narco 150 Transponder.

The best all around deal out there for ads-b-out on legacy airplanes seems to be the GTX-335 with GPS that's approved for your mechanic to install ($2995). You get a new solid state transponder and 1090 in case you ever go into the flight levels or outside of the U. S.  

Using one of the UAT gizmos with an older cavity tube transponder is just kicking the can down the road. It's going to eventually need to be replaced.

I ended up with the GTX-345 and really like it.

OR one of the Trig units. 978 and 1090.   I would help with the issue, but just got through fixing a SalesForce rollout that got dumped on me and the account manager and have to go fall on a sword with our customer tomorrow.    combining multiple systems has multiple failure points.   I ran around all last week telling people not to do a big bang system conversion.   Big bang means big failure.

 

[carusoam]

Hey...

Didn’t Salesforce/CRM acquire Mulesoft to help out with that integration thing?  https://www.mulesoft.com/press-center/salesforce-acquisition-completed

Mr. Benioff is a great leader with a tremendous following...

Good luck with the sword tomorrow...

Best regards,

-a-

[Immelman]

Taracka...

 

I got the same letter in the mail.

Look closely at the report of the failed flight they sent you in the letter. Was it before you got all the kinks worked out?

I bought the skybeacon, first flight failed, adjusted transponder threshold, second flight passed. Got the rebate check and everything.

Then the letter shows up Friday. The enclosed report was from my first (failed) test flight that I had already corrected...

 

I am curious how my experience compares to yours. I'll be calling the FAA guy this week.

 

 

[vorlon1]

19 hours ago, Taracka said:

About a month ago, I installed a Uavionix Skybeacon on my M20C.  Initially there was an issue with the Transponder monitor threshold needing adjustment to work with my Narco AT 150 transponder.  After 4 test flights I got that worked out, passed, and got the rebate.  About a week ago, I received a certified letter from Mike Smith at the FAA in Washington DC stating my ads-b failed...

Ok, what changed between these flights? 

I too have the Narco 150. I adjusted the skybeacon threshold to 30 (based on reading other reports) and passed on the first attempt.

[1964-M20E]

8 hours ago, Cruiser said:

SDA failure mean you do not have a valid GPS source.

This could be a configuration setting or an actual signal failure 

Thanks at least I know what that means now.  It would be nice if they gave out the secret decoder ring included in the report.

SDA appears to be popping often up so maybe the avionics shops didn't configure something right.  I have the Avidyne IFD540 connected to the Avidyne APX322 so there should not be any issues between the two.  I would hope.

 

 

[1964-M20E]

16 minutes ago, vorlon1 said:

Ok, what changed between these flights? 

I too have the Narco 150. I adjusted the skybeacon threshold to 30 (based on reading other reports) and passed on the first attempt.

One thing that has changed is the FAA is focusing on ADSB errors this now with 2020 coming up very soon.  This is from the mouth of the FAA guy I spoke with last Friday.

[Cruiser]

2 hours ago, 1964-M20E said:

Thanks at least I know what that means now.  It would be nice if they gave out the secret decoder ring included in the report.

ADS-B PCR User's Guide April 8 2016 - PCR Theme.pdf

[Marauder]

1 hour ago, Skmoore63 said:

I had several failed attempts to certify my Garmin 335 transponder for ADS-B which I tried to do on my normal flights into Memphis, just holding in the area and maneuvering to get the requisite time. I finally went to a different airport(BNA) and just told approach what I wanted to do (hold and maneuver in their airspace), they let me do that, and I was certified in one flight. 

Not saying this will help you, but I was getting pretty frustrated with the Garmin transponder and my avionics shop--turned out it was more of a ground facility problem than anything else.

I had the same experience with my Lynx here. My first flight was around the Philly Bravo and I figured I spent enough time in the "zone" only to find out that I needed more time in it. The analyst who reviewed my data looked it over and passed me.

[1964-M20E]

I just spent about 30 minutes talking with Mr. Denny from the FAA and he was very nice.

1. We discussed the consistent problem I have had since installation of my IFD540 and APX322.  The problem is SDA (system design assurance).  He believes it may just be a configuration problem or software issue in the Avidyne. 

2. I contacted my avionic shop and he confirmed that Avidyne has an update to be release by the end of the month.

3. Hopefully I can get over there and get it take care of and all will be good.

 

More updates will be made as things develop.

 

 

[Cruiser]

Configuration maybe, software ? not so much, there are many (including me) flying around with current Avidyne IFD540/440 units working perfectly fine with ADS-B OUT installed.

Yes, there is a software upgrade coming from Avidyne but it will not address your problem.

[1964-M20E]

well it's a plan for now

[Taracka]

19 hours ago, Immelman said:

Taracka...

 

I got the same letter in the mail.

Look closely at the report of the failed flight they sent you in the letter. Was it before you got all the kinks worked out?

I bought the skybeacon, first flight failed, adjusted transponder threshold, second flight passed. Got the rebate check and everything.

Then the letter shows up Friday. The enclosed report was from my first (failed) test flight that I had already corrected...

 

I am curious how my experience compares to yours. I'll be calling the FAA guy this week.

 

 

Immelmann,

I had two failed flights before the third one that passed getting me the rebate and yes, they counted those.  I have corresponded with the FAA guy and he’s saying it’s a setup issue.  I will try working with Uavionix to see if we can come up with a solution.  So far, they think it’s an Ads-b fringe area issue.  What I’ve found after numerous flights is the only transponder monitor threshold setting that works at least some of the time is 39%.  With this setting I’ve had four passing flights and three with mode 3A fails ranging from 1 to 22 percent.  A transponder check was done very recently and everything checked out on the transponder.  While I realize the AT150 is a thirty year old transponder, Uavionix claims their product will work with ALL transponders.  I will update as I know more.

[bob865]

11 hours ago, Taracka said:

Immelmann,

I had two failed flights before the third one that passed getting me the rebate and yes, they counted those.  I have corresponded with the FAA guy and he’s saying it’s a setup issue.  I will try working with Uavionix to see if we can come up with a solution.  So far, they think it’s an Ads-b fringe area issue.  What I’ve found after numerous flights is the only transponder monitor threshold setting that works at least some of the time is 39%.  With this setting I’ve had four passing flights and three with mode 3A fails ranging from 1 to 22 percent.  A transponder check was done very recently and everything checked out on the transponder.  While I realize the AT150 is a thirty year old transponder, Uavionix claims their product will work with ALL transponders.  I will update as I know more.

The trasponder threshold is finicky I found.  I failed my first flight, made and andjustment to 35% (if I remember right) and it worked well.  Flew again and it was slow to get the squawk from the transponder so I thought if 35% is good 30% should be better.  Nope!  It performed worse there than at the factory defaults.  I changed it back before I flew the plane back from wet wingologist and it worked perfectly.  The flight missed rule airspace by 5 minutes and got an e-mail immediately following saying they were manually reviewing and I didn't need to fly again until I heard from them.  The manual review passed and now my rebate is on the way.

[Yetti]

This is interesting.   I work in the sensor industry.  You know remote controlling data gathering on pipelines and refineries and production fields with 2000 wells.   Sounds like they are getting ADSB data, but not transponder mode C.   So it throws a flag.   Interesting enough if you have ADSB why do you have to put a transponder code in?  I mean they should know who you are.   An Austin pilot got a random traffic alert call from ATC.   "If you are on frequency"   ADSB snitched on him with the N Number.

@carusoam  I remain committed to my belief that there is not bad software there are bad software rollouts

[Marauder]

Ok,  i just installed my uAvionix and I believe I know exactly the problem...
My first flight for certification flight failed mode 3A at 2.02% (meaning that it responded with interrogations for 97.8% of my total flight and apparently that is not good enough for the FAA).  UAvionix also told me that my airport FROM WHICH I AM BASED is within a “fringe area” but uAvionix is not clear wherther that area is referring to an ADSB area, or a Transponder/RADAR coverage area— until I asked them for clarification.  Apparently you MUST not only have good ADSB coverage during the entire flight, but adequate TRANSPONDER interrogation coverage ON THE GROUND AT YOUR TAKE OFF AND LANDING AIRPORT AS WELL.  Any flight that shows ADSB / Transponder discrepancies during ANY phase of the flight including ground ops is considered a failed flight, and the FAA will get all mad because they cannot confirm your flight unless they have you interrogated you via both systems at or near 100%.  If there is a discrepancy from the time you are rolling with your wheels on the ground till the time you land and tie down you will fail that magic 2% mode 3A threshold and be deemed a failed flight.
So, my question to you folks who got a letter from the FAA did you get that letter when you flew from, or landed at an airport that did not have Radar or transponder coverage all the way to the ground?  For those of you failing Mode 3A at higher percentages, were you flying in remote areas with poor radar or transponder coverage?
At least this is the explanation I got from UAvionix.  They told me to fly to an airport with known good RADAR coverage on the ground, complete the 30 minute test flight above 3000 feet, do two circles in each direction and LAND at the same airport.  The FAA will probably be sending me a LOT of letters since I typically fly in remote areas, often at low altitudes.

Phil - the ground radar comment is absolutely not correct. Only larger airports will have ground “radar”. This is why we have been asked to leave our transponders on or in ground mode when we are these airports. I certainly didn’t need to do what they said needs to be done.

The FAA has a map showing the compliance areas and you need to spend 30 minutes within that airspace. This includes the airspace above 10,000.


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[Taracka]

So First off, I flew the other morning  down to the Seattle mode c ring to confirm my suspicion that the issue is local radar interference.  We have two maritime shore based radar stations here and I noticed the mode 3A failures occurred near them as well as on the ground.  The report for my flight today showed zero errors.  It seems my mode c is hit and miss on the ground (today luckily it was hit), probably a product of marginal reception of the nearest atc facility.

  I received an email also the last week from the FAA guy stating they are investigating the following issues and that I should fly as normal until they get it figured out. They acknowledge there is an issue with mode 3A errors with the Skybeacon such as when the aircraft is on the ground in a non-coverage area and the transponder isn’t being interrogated, and yes, you will fail a test flight if this happens, they don’t care that it wasn’t in “rule” airspace.  They are working with Uavionix engineers on this issue.  The FAA guy also indicated they need to have an internal meeting and determine what an acceptable level of performance is outside of “rule” airspace.  This confuses me since it isn’t required in those areas.  He said he would advise me when they have determined this.