ADSB Length/Width Code (LWC) Failure

[One Whiskey Hotel]

Received a phone call from FAA today regarding ADS-B broadcast inconsistencies, specifically the LWC column which I understand contains aircraft length and width information.

My K model is equipped with Garmin GTX-330ES and GDL88 for dual out capabilities. How is this information coded? How does one correct an LWC exception? I’d like to send my avionics shop in the right direction if anyone knows about these intricacies of ADS-B. 

Regrettably I’m now proudly on the FAA’s NSAL filter, meaning I am denied ADS‐B based ATC services, including the suppression of Traffic Information Services‐ Broadcast (TIS‐B) data. Proudly at the top of yet another government watch list...this isn’t a first! But on a serious note, does this affect how I might file IFR? Should I change equipment codes when filing, as if I was not ADS-B equipped for example, until this issue is resolved?

According to the inspector I spoke with, this problem has been consistently noted since 8/2016, TWO YEARS AGO, and that may be simply due to the time it took for Oklahoma City to complete my registration when I bought the airplane and associate the issue with me. I can only assume this is the efficiency of the bureaucracy which is the FAA....

 

 

 

 

 

 

 

 

 

Edited August 16, 2018 by One Whiskey Hotel

[N201MKTurbo]

They are configuration settings in your transponder and UAT. You just need to enter the correct numbers. 

Download the install manuals for instructions on how to change them. 

[Alan Fox]

You probably had a software upgrade , on the 430/530 , and not the other equipment.....

[Marauder]

Speaking of weird ADS-B anomalies. Got a ride last night over to Robbinsville to pick up my Mooney. The Cherokee that brought me over (yeah, I know, I’m a sinner) followed me back. He reported an ADS-B target just north of Philly’s Class B labeled “TEST” and it was showing initially 28 knots ground speed. It then sped up to 285 knots and then disappeared. He said it showed movement on the display. I was too far ahead of him and didn’t see it.

Anyone seen anything like this?


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[N201MKTurbo]

2 minutes ago, Marauder said:

Speaking of weird ADS-B anomalies. Got a ride last night over to Robbinsville to pick up my Mooney. The Cherokee that brought me over (yeah, I know, I’m a sinner) followed me back. He reported an ADS-B target just north of Philly’s Class B labeled “TEST” and it was showing initially 28 knots ground speed. It then sped up to 285 knots and then disappeared. He said it showed movement on the display. I was too far ahead of him and didn’t see it.

Anyone seen anything like this?


Sent from my iPad using Tapatalk Pro

 Haven’t seen one labeled “test”, but twice while flying by the army proving grounds near Yuma I would see traffic targets that zoomed by me at the same altitude less than a mile away. I never saw anything. I think somebody was messing with me.

There are almost constant NOTAMS about “GPS testing” in that area. They never say what GPS testing means.

[Andy95W]

What's the point of having "dual out" capabilities?  That's the first thing that seems kind of weird to me.  

Once you get the configuration set up correctly, I'd pull the breaker for the GDL-88 when you do your test flights.  And then consider removing it and selling it.

[bob865]

I don't know about dual out, but the GDL-88 is in also.  Weather etc is only on the UAT frequency.  I agree that transmitting both is redundant, but I can see why he would have both devices and not wanting to disable it.

 

[Andy95W]

Good point, Bob, thanks for pointing that out.  Perhaps the "Out" portion of the GDL is disabled since he has the 330ES.  

My understanding of the regs is that, as with transponders, you may have more than one installed but could not transmit on both simultaneously. 

[jonhop]

19 hours ago, One Whiskey Hotel said:

how I might file IFR?

You are good until 2020 and then you can't get into a mode C veil...

 

19 hours ago, One Whiskey Hotel said:

I’d like to send my avionics shop in the right direction if anyone knows about these intricacies of ADS-B. 

I had air on ground errors after my GTX-345 install and the shop my knew exactly what was wrong and told me how to fix it. Taxi slower than molasses... or fire up the transponder in the runup area. Have you informed your shop? They may already know how to help.

[MBDiagMan]

On 8/16/2018 at 7:30 AM, Marauder said:

Speaking of weird ADS-B anomalies. Got a ride last night over to Robbinsville to pick up my Mooney. The Cherokee that brought me over (yeah, I know, I’m a sinner) followed me back. He reported an ADS-B target just north of Philly’s Class B labeled “TEST” and it was showing initially 28 knots ground speed. It then sped up to 285 knots and then disappeared. He said it showed movement on the display. I was too far ahead of him and didn’t see it.

Anyone seen anything like this?


Sent from my iPad using Tapatalk Pro

Too far ahead of him to see it?  Oh, surely not!

[Marauder]

Too far ahead of him to see it?  Oh, surely not!

Oh yeah! He fell out of the TIS-B and TAS cone.


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[One Whiskey Hotel]

Learn something every day: the GTN-750 has the config settings for all the Garmin goodies, including the GDL88 and GTX330ES, not just the radio stack itself. Held the button down on power up and scroll to the right setup screen; the length/width parameters for the ADSB are in there. Mine was set correctly for wing span (36) but the length was accidentally set up for 85m of length. Should be good now, and while this problem was super obscure and uncommon, hope this follow up post might help someone else one day. Just like any computer, it’s only as smart as the person behind the screen; tell it the wrong stuff and the FAA calls. No biggie though, all is well.

Tailwinds and blue skies....