Thinking about ADS-B

Hi all,
I am looking for options to install a full ADS-B installation (In and Out) in my Glastar, primarily for traffic. I am currently using WingX on an iPad mounted to my panel, and would like to use that as the display for the ADS-B.

One popular option is the Naxworx system, and they seem to have a good following in the aviation community.

One concern that I have with the Navworx solution is that it is a single frequency receiver (978 Mhz). In areas of no radar or TIS-B coverage, of which there are a bunch here in Maine at the lower altitudes that I often fly (3k), I would not receive any ADS-B info for any aircraft using the 1090Mhz ADS-B system. If I had a dual channel receiver, I would receive this traffic since the system would be picking up the ADS-B signal transmitted directly from the other aircraft even in areas of no radar or TIS-B coverage.

Given that, a second option might be to go with a dual channel ADS-B receiver such as the Skyradar or Sagetech Clarity units, and install a separate ADS-B transmitter. I currently have a KT76A transponder, and I believe that the Trig TT31 transponder would replace my KT76A, and also provide the ADS-B out signal (on 1090 Mhz).

The rest of my panel is old style steam gauges, so there is nothing else that would be interfaced with the ADS-B system at this time other than the iPad.

I'd like to get thoughts on both of these options (or others if you know of them), and also try to figure out what would be a total cost of implementation for each so that I can compare.

Thanks,

-Dj

ADS-B, Yes...

DJ, can't answer your question, but something that you should know.

Any aircraft that is too low for ATC to pick up there transponder, will not show up even when you get coverage. The only targets that you will see are the ones that ATC can see.

I discovered this recently when flying on a 'poker run' with a friend. My NavWorx was working great but sometimes I couldn't see him. Most of the time I had him in site, but kept asking him if he had forgot to turn on his transponder. As it turned out he kept dropping down to get a closer look at the river and ATC wasn't putting him in the FIS-B packets.

I love my setup, NavWorx / AFS EFIS. I can find targets quickly with the help of the display. But you need to keep an eye out because not everyone shows up.

Also of note, is that the altitude reported my be off because it effect by the accuracy of the other guys transponder check.

Kent

kentb said:

Any aircraft that is too low for ATC to pick up there transponder, will not show up even when you get coverage. The only targets that you will see are the ones that ATC can see.

Click to expand...

Hi Kent,
That is correct for those aircraft that are only equipped with a transponder and do not have ADS-B Out.

However, I would be able to see all aircraft equipped with ADS-B Out if I went with the dual channel receiver, regardless of their altitude. I'm trying to think ahead presuming that we will see more aircraft equipping with ADS-B Out over the next 8 years, with most having it by 2020.

If I went with the single channel Navworx, I can envision a scenario where I might be below TIS-B coverage so not getting the updates, and a biz jet equipped with 1090 Mhz ADS-B is coming in for approach at one of the nearby airports. I would not see him on ADS-B because I'm not in TIS-B coverage and I'm not receiving 1090Mhz, and he would not see me because he is on 1090 Mhz and I would be transmitting on 978 Mhz, yet he very well could be making an approach to landing that would cause him to pass near me.

Has anyone equipped with 1090 Mhz out and is using a dual channel ADS-B receiver? Is it vastly more expensive to do so?

-Dj

A 1090ES ADS-B receiver only picks up other planes that have ADS-B out via their transponder. It can't pick up standard Mode A/C transponders, or even basic Mode S transponders. Only Mode S with Extended Squitter.

We recently went flying in Seattle and saw 150 unique targets on ADS-B in one hour. Only one of them was a GA plane with ADS-B out. The rest came because of TIS-B radar coverage, or because they were airliners (which are always IFR so aren't an issue when you are in areas with no radar coverage).

All of this is to say that at least today, very, very few GA planes are ADS-B out equipped, and thus you will not see a lot of extra traffic because of 1090 reception. This will increase as you move towards 2020, but so will ADS-B ground station coverage.

--Ian Jordan
Dynon Avionics

dynonsupport said:

or even basic Mode S transponders. Only Mode S with Extended Squitter.

Click to expand...

Thanks! I didn't know there was a difference between Mode S and Mode 1090ES.

The transponder I was looking at is the Trig TT31 1090ES.
http://www.aircraftspruce.com/catalog/avpages/trigtt31.php

I believe this will do what I want, but what I don't know is what other parts need to be added to it in order to make it do the ADS-B Out function, and at what cost.

-Dj

Recent experience ... It should all work fine

deej said:

Thanks! I didn't know there was a difference between Mode S and Mode 1090ES.

The transponder I was looking at is the Trig TT31 1090ES.
http://www.aircraftspruce.com/catalog/avpages/trigtt31.php

I believe this will do what I want, but what I don't know is what other parts need to be added to it in order to make it do the ADS-B Out function, and at what cost.

-Dj

Click to expand...

Just helped a friend ("Widget" from Team RV) install a Trig TT31 for the reasons you mention.

We have glitch but it all works. Here what he has.
(I am writing this as I think he is travelling at the moment.)

TT31 1090 ES
SkyRadar D2
iPad +WingX
Garmin 496
GRT EFIS (Sport)


The Garmin provides WAAS GPS signal to the TRIG (and YES it is NOT certified. But yes it is not 2020 yet.)

The TRIG plugs into the KT76 tray **IF** you don't want ADS-B support. Otherwise you replace that tray with theirs (mechanical plug-n-play). On the back of the TRIG tray is another connector to provide the WAAS GPS signal in along with a couple other options (e.g. TIS out I think).

The SkyRadar D2 is dual mode so it is listening to 978Mhz and 1090Mhz.
The SkyRadar D2 feeds his GRT EFIS via "hardwire" (USB).
The SkyRadar D2 feeds his iPad with WingX via WiFI.

The "glitch" we have been working is that he sometimes gets a no ADS-B position available message but a second later it **IS** there and correct.

He also has found a discrepancy in reported altitude (via ADS-B). We are testing to find the source as the GRT, Transponder and Garmin all REPORT the right altitude and ATC "sees" the right altitude. :-(

Once he lands and catches up, I am sure he will correct my errors.


James

jclark said:

TT31 1090 ES
SkyRadar D2
iPad +WingX
Garmin 496
GRT EFIS (Sport)

Click to expand...

Thanks, James! That is very close to what I was picturing, sans the GRT EFIS.

Other than the glitch, does it all seem to work as expected?

Does the glitch show up on the GRT, WingX, or both?

-Dj

Works as advertised (other than glitch being tracked)

deej said:

Thanks, James! That is very close to what I was picturing, sans the GRT EFIS.

Other than the glitch, does it all seem to work as expected?

Does the glitch show up on the GRT, WingX, or both?

-Dj

Click to expand...

Short answer: Works as expected modulo below ...

---------------
The glitch shows up on the TT31 display. Discussing this with TRIG to try to understand what is happening.

We *****MIGHT***** have a stray wire or a loose connection from the 496. We are going to check that. It is such an anomaly that we know it has to be something oddball. It is otherwise working ... EXCEPT ....

As mentioned, others get a WRONG altitude from the ADS-B system. So we are doing tests to find what is causing that. Everything has been checked many times and SEEMS to be connected and configured correctly.

We have been studying NMEA 0183 sentences and comparing data readouts and all seems to be happy.

I plan to do a similar setup later as well.

James

jclark said:

The glitch shows up on the TT31 display. Discussing this with TRIG to try to understand what is happening.

Click to expand...

Thanks James, I greatly appreciate your feedback. Please keep us posted on your progress tracking down the issue.

I'm thinking of doing this as a winter upgrade project, Jan-Feb timeframe.

Cost-wise, it looks like the Navworx single channel solution would be about $2850, and the dual channel solution would be about $3300, however I can probably turn around and sell my existing KT76A transponder for a few bucks so the dual channel solution might end up being cheaper for me all told.

Thanks!

-Dj

deej said:

Thanks James, I greatly appreciate your feedback. Please keep us posted on your progress tracking down the issue.

I'm thinking of doing this as a winter upgrade project, Jan-Feb timeframe.

Cost-wise, it looks like the Navworx single channel solution would be about $2850, and the dual channel solution would be about $3300, however I can probably turn around and sell my existing KT76A transponder for a few bucks so the dual channel solution might end up being cheaper for me all told.

Thanks!

-Dj

Click to expand...

That's about right. You could get a brand new Trig TT31 + a GDL39 dual channel ADSB box that'll work with your Garmin portable and the iPad/iPhone (but not wing-x), and still end up around $3300. The bonus there is dual channel, plus an additional GPS that can feed your iPad via bluetooth, 795, etc..

For those with no glass in the panel other than an iPad or something, at the moment we've found the GDL to be one of the best solutions available. Also, as the other brands have boxes come on line that may change, but for those without glass in the panel, the GDL39 pretty much wins all the way around. However, if you have an EFIS in your panel or are planning an EFIS (or some panel mount GPSes), then my advice may change. It's just pretty hard to beat a dual channel box that is wireless with a GPS receiver in it for $750 or so.

Just my 2 cents as usual.

Cheers,
Stein

One more piece of information.

Not sure how this relates to other solutions to ADS-B, but in my case....
My transponder currently installed does not send my squawk code to the NavWorx unit. I am looking into replacing my Narco 165 with something that can send the squawk code to the ADS-B box.
I think that it would be a Garmin 327, but still need to get feedback from Bill Moffit (NavWorx) if this is the right way to go.

Kent

SteinAir said:

It's just pretty hard to beat a dual channel box that is wireless with a GPS receiver in it for $750 or so.

Click to expand...

How about a dual channel box that is wireless with GPS receiver for $680? The Skyradar D2 is on sale right now...

The GDL39 looks like a nice box, but the lack of WingX compatibility kills it for me.

I'll contact you directly to see about buying the Trig system, though.

Thanks!

-Dj

+1 for the Skyradar

I just received my dual channel Skyradar unit today - best deal I could find with the 20% discount......

I was going to hold out for the Sagetech until they delayed shipping again. In the end, I'm perfectly happy with the Skyradar unit since it works perfectly while sitting on top of my battery box near the floor of the cockpit (RV6)! It feeds to my i720 iflyGPS, and gets clear reception as installed while sitting inside of my all metal hangar. I think it gets the nexrad data displayed faster than my XM unit did.

Don

deej said:

How about a dual channel box that is wireless with GPS receiver for $680? The Skyradar D2 is on sale right now...

The GDL39 looks like a nice box, but the lack of WingX compatibility kills it for me.

I'll contact you directly to see about buying the Trig system, though.

Thanks!

-Dj

Click to expand...

That's a perfectly fine solution too. I have all three app's on my pad (WingX/FF/Garmin)-and each has their pros and cons. In the end I'm now getting used to the Garmin app, and with their last software upgrade it's not pretty much in the same league as the other two, and now that it's only $50 (yes, I still have to pay for these things), it's made it more attractive to me. I still like all of them for various things, but I think with the GDL and the Garmin app, I'll probably let WingX and ForeFlight expire next year. Anyone that'd tell you that either of these three apps is worthless isn't being honest, because each one is pretty good. If they weren't they wouldn't survive! We each use what we like and all of them are pretty good. In fact, all of them are downright remarkable if you look back even 5 years as to what we had available. Pretty amazing really.


Cheers,
Stein

I'm curious, with the GLD39, SkyRadar or iLevil, can one use the GPS information from these devices and send it to the TT31? I'm guessing no, but hey, would be great if possible.