GDL-88 opinions

[azure]

I've been waiting for an opening at my avionics shop to install a GDL-82, but the shop learned last week that that unit is not an option for my plane if I want ADS-B in displayed on my GMX-200, because my current GDL-90 will stop receiving ADS-B traffic sometime in March 2020 due to "synchronization issues", they told me. So I'm looking for alternatives.

The two that the shop has suggested are the GDL-88 and the GTX-345r (r because my 480 can apparently command the transponder remotely as it does now my SL-70r). The GDL-88 would replace the GDL-90 only, and the GTX-345 would replace both the GDL-90 and the SL-70r, but the GTX-345 is an AMU more, which I would not get back in trade-up for my much older SL-70r.

With a Cardinal RG, I will never be flying in airspace where I need the 1090 ES technology, so I'm leaning toward the GDL-88.

Does anyone out there have experience with this unit, or the GTX-345? Any disadvantages or gotchas with either that I should know about?

 

[John Collins]

I have a GDL88 installed with a non ES version of the GTX330. it should interface with the GMX200 and can use the GNS480 as a position source. If you add a FS210 to the installation, you can get weather and traffic via BT. I don't think the ground stations will support TISB for the GDL90 after the end of this year. I would install the GTX 345 rather than the GDL88, it is equivalent in price and easier to install than a GDL88/FS210.

 

[denverpilot]

The GDL-90 thread two years ago here explains better why it’s dead. Just thought it was interesting it comes up in a google search about them.

Also interesting that in only two years all the external links including the FAA equipment approval list are stone dead.

https://www.pilotsofamerica.com/community/threads/gdl-90-and-adsb-mandate.102834/

 

[MooneyDriver78]

The GDL88 won’t interface with the G3X, so no traffic/weather.


Tom

 

[Unit74]

I've been waiting for an opening at my avionics shop to install a GDL-82, but the shop learned last week that that unit is not an option for my plane if I want ADS-B in displayed on my GMX-200, because my current GDL-90 will stop receiving ADS-B traffic sometime in March 2020 due to "synchronization issues", they told me. So I'm looking for alternatives.

The two that the shop has suggested are the GDL-88 and the GTX-345r (r because my 480 can apparently command the transponder remotely as it does now my SL-70r). The GDL-88 would replace the GDL-90 only, and the GTX-345 would replace both the GDL-90 and the SL-70r, but the GTX-345 is an AMU more, which I would not get back in trade-up for my much older SL-70r.

With a Cardinal RG, I will never be flying in airspace where I need the 1090 ES technology, so I'm leaning toward the GDL-88.

Does anyone out there have experience with this unit, or the GTX-345? Any disadvantages or gotchas with either that I should know about?

I have had both. Current 345 operator. Slap a Flightstream 210 on a GDL88 and it's a good option. Both will feed your iPad in that configuration. I actually have a 210 and 345 though , becuase I wanted the AHRS as well. But betwen the 345 and the GDL bare bones, if all you want is compliance, I would not be looking at either. Both are expensive unless you can get a used GDL. What are you really trying to accomplish? basic compliance or do you want an ADSB data feed?

 

[azure]

Thanks for the replies so far. I'm not sure why people are talking about the FS 210 as I'm not interested in interfacing with an iPad. I have a GMX-200 and either the GDL-88 or the GTX-345 will interface with it and display both TIS-B traffic and FIS-B weather on it. With my 480 I don't believe uploading flight plans from an iPad is even an option. And in any case I really don't want to be looking down to see traffic or weather. I like my GMX-200 just fine - when it isn't crashing, that is (it's currently out to Garmin for repairs, I suspect a failed internal cooling fan or similar).

@John Collins, yes, that is what my shop confirmed, TIS-B with the GDL-90 will become increasingly unreliable during 2020 and eventually cease to work altogether. Why is the GTX-345 is easier to install than the GDL-88? Also, in terms of list price they aren't equivalent; the GTX lists for $4995 and the GDL for $3995, and my shop says they can get one for a couple $100 cheaper.

 

[John Collins]

A panel mounted transponder is closer to what it needs to connect to, power, the GPS source, the audio panel (for alerts), the altitude encoder, the GMX200, and usually it is replacing the transponder. Mounting a remote box needs to run cables to the front to connect to the existing avionics/power and may need to have a mounting constructed. So if the GDL88 is not installed in the front, one needs to open up the tail, the side panels, and the front avionics in the panel. The GTX 345 includes BT for weather, trafic, GPS source, AHRS for an iPad, you need to add a FS210 to get the same function. So when you add in extra installation labor and a possible FS210, it is more than the GTX 345 with all that stuff self contained.

Edit, also the altitude encoder may have to be changed for both the transponder and the GDL88 because they must use the same source and if the existing transponder uses a parallel encoder, it won't work with the GDL88.

My understanding is that the software update in the ground stations will turn off TISB support for RTCA DO 282A, 260, and 260A devices. The GDL90 is RTCA DO 282A. I would not count on any TISB in 2020 for a GDL90.

 

[DA40FAN]

If you do any flying where you want to operate under a different call sign, e.g., Angel Flights, you cannot do so with the GDL88 because you can't change the tail number that the unit broadcasts (at least not without hooking up a special cord to a laptop). The FAA has ruled that your tail number on your flight plan and that is broadcast by your ADSB must be the same. The GTX345 does allow you to easily change as required.

 

[bnt83]

Without seeing the interfaces my guess is that most of the wiring to the GDL90 can be reused on the GDL88, and the SL70 for another remote transponder

All I can say is 345R + GDL88 sounds awefully expensive just to get stuff displayed on the GMX200. It's that setup even well tested? Id be upset if I put all that in and it didn't work well.

 

[Unit74]

Assuming you have a 430/650 WAAS navigator, save the money and get a GTX 335 if you don't want any iPad connectivity. Honestly, you are a good candidate for the uVavionics products it sounds. Bare bones legality needs. Good product, installs in an hour and legal!

 

[denverpilot]

The FAA has ruled that your tail number on your flight plan and that is broadcast by your ADSB must be the same.

Need to cite two sources on this one.

The document where FAA says that.

The document that says you can’t fly the charitable flight under the aircraft tail number and still coordinate with ATC as if you’re on the charity callsign.

Got the ruling handy? This is a pretty big policy change if accurate.

 

[azure]

A panel mounted transponder is closer to what it needs to connect to, power, the GPS source, the audio panel (for alerts), the altitude encoder, the GMX200, and usually it is replacing the transponder. Mounting a remote box needs to run cables to the front to connect to the existing avionics/power and may need to have a mounting constructed. So if the GDL88 is not installed in the front, one needs to open up the tail, the side panels, and the front avionics in the panel. The GTX 345 includes BT for weather, trafic, GPS source, AHRS for an iPad, you need to add a FS210 to get the same function. So when you add in extra installation labor and a possible FS210, it is more than the GTX 345 with all that stuff self contained.

Edit, also the altitude encoder may have to be changed for both the transponder and the GDL88 because they must use the same source and if the existing transponder uses a parallel encoder, it won't work with the GDL88.

My understanding is that the software update in the ground stations will turn off TISB support for RTCA DO 282A, 260, and 260A devices. The GDL90 is RTCA DO 282A. I would not count on any TISB in 2020 for a GDL90.

Well, the cables are already in place for a GDL-88 I believe. Also for the SL-70r remote transponder. Are the interfaces the same for the GTX-345r? That was the version my shop is suggesting, just replace the SL-70r and the GDL-90 with the GTX-345r. But they seemed to think that the GDL-88 would be a simpler installation, little more than a swap out of the GDL-90 and swap in the GDL-88, plus configuration of the new unit, and I would of course keep the SL-70r. That assumes that Garmin's "auto-squawk" will work with the SL-70r.

I'm not sure what type of encoder I have. Does the fact that the existing transponder is a SL-70r tell you?

 

[azure]

Without seeing the interfaces my guess is that most of the wiring to the GDL90 can be reused on the GDL88, and the SL70 for another remote transponder

Yes, that's exactly why my shop thought that would be the simplest installation.

All I can say is 345R + GDL88 sounds awefully expensive just to get stuff displayed on the GMX200. It's that setup even well tested? Id be upset if I put all that in and it didn't work well.

???

The 345r and the GDL-88 are alternative possibilities, I'm definitely not considering having both installed. Either can display on the GMX-200 - the avionics genius at the shop looked it up while I was standing there and said yes, the GMX-200 is a "supported" display device for either one.

 

[azure]

Assuming you have a 430/650 WAAS navigator, save the money and get a GTX 335 if you don't want any iPad connectivity. Honestly, you are a good candidate for the uVavionics products it sounds. Bare bones legality needs. Good product, installs in an hour and legal!

I have a GNS-480 / CNX-80, not a 430, and not a 650.

 

[murphey]

Thanks for the replies so far. I'm not sure why people are talking about the FS 210 as I'm not interested in interfacing with an iPad. I have a GMX-200 and either the GDL-88 or the GTX-345 will interface with it and display both TIS-B traffic and FIS-B weather on it. With my 480 I don't believe uploading flight plans from an iPad is even an option. And in any case I really don't want to be looking down to see traffic or weather. I like my GMX-200 just fine - when it isn't crashing, that is (it's currently out to Garmin for repairs, I suspect a failed internal cooling fan or similar).

@John Collins, yes, that is what my shop confirmed, TIS-B with the GDL-90 will become increasingly unreliable during 2020 and eventually cease to work altogether. Why is the GTX-345 is easier to install than the GDL-88? Also, in terms of list price they aren't equivalent; the GTX lists for $4995 and the GDL for $3995, and my shop says they can get one for a couple $100 cheaper.

The 345 MRP is 5K but most, if not all, the vendors and Garmin dealers are retailing it for $4500. Don't forget that Garmin often offers rebates to the dealers that can be negotiated.... the GDL is retailing for less than $3500.

 

[John Collins]

Need to cite two sources on this one.

The document where FAA says that.

The document that says you can’t fly the charitable flight under the aircraft tail number and still coordinate with ATC as if you’re on the charity callsign.

Got the ruling handy? This is a pretty big policy change if accurate.

There are multiple sources for this, but here is the FAA General Counsel opinion. https://www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/interpretations/Data/interps/2017/Hayslett-AJM-2 - (2017) Legal Interpretation.pdf

It is not required that a flight plan be filed using a call sign to conduct an Angel Flight, but if one is used, the ADS-B Out broadcast must match the filed call sign. Not all ADS-B Out installations are capable of having a call sign entered and many more (most) are not configured to enable this if it is a capability.

Edit: https://www.faa.gov/nextgen/equipadsb/installation/call_sign/

 

[bnt83]

I would get the 345/345r and be done with it. If you get the 88 you'll be hunting for a used SL70R when it quits. 1090 out is required 18k and up, not that your 177RG goes up there regularly but, 88 is 978 out only...

 

[WannFly]

Are you referring to your panel or mine? Lol. Seems like a copy paste... I am going to 345/345R, exact same boat as you

 

[azure]

I would get the 345/345r and be done with it. If you get the 88 you'll be hunting for a used SL70R when it quits. 1090 out is required 18k and up, not that your 177RG goes up there regularly but, 88 is 978 out only...

Of course, the 345R could quit too, but I get your point... my tailcone avionics are old and long in the tooth. It might be a wise move to replace both the GDL-90 and the SL-70r. But we (the avionics shop and I) would need to do a bit more research into what is entailed in making the 480 command the 345R reliably. The 480 / SL-70r interface is the flakiest part of my installation. Every once in a while the 480 reports "Unable to command transponder". It happened during my recent IFR certs, and then went away by the time I started up to return home. Whether it's a pin not quite seating correctly or some intermittent conflict between devices, if I'm going to spring for something as expensive as a 345R I want to be sure that gremlin isn't going to rear its ugly head with it.

 

[azure]

Are you referring to your panel or mine? Lol. Seems like a copy paste... I am going to 345/345R, exact same boat as you

That's interesting! I thought my panel was pretty unique. Let's see...

GNS-480
GMX-200
Sandel 3500 eHSI
SL-30 as NAV/COM2
STEC-20 + VSS
WX-900 Stormscope
SL-70R (and a panel-mounted SL-70 too)

and in the tail, a GDL-69 for XM weather and the GDL-90.

 

[denverpilot]

There are multiple sources for this, but here is the FAA General Counsel opinion. https://www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/interpretations/Data/interps/2017/Hayslett-AJM-2 - (2017) Legal Interpretation.pdf

It is not required that a flight plan be filed using a call sign to conduct an Angel Flight, but if one is used, the ADS-B Out broadcast must match the filed call sign. Not all ADS-B Out installations are capable of having a call sign entered and many more (most) are not configured to enable this if it is a capability.

Edit: https://www.faa.gov/nextgen/equipadsb/installation/call_sign/

Thanks for the reference.

That’s interesting. Now I want to go see what the 7110 says about it. If anything.

I assume the “problem” of a mismatch is easily fixed by the controller on their side, and can’t imagine they’d leave out a way to override ADS-B since it’s not secured, easily spoofable, and any idiot could take off with the wrong 24-bit code in a transponder by total accident, ESPECIALLY with a changeable one and a typo.

Be interesting to know how many flight numbers are set wrong in the NAS on a daily basis.

That’s a user interface input box and can be screwed up. You never identify things off of user input if you can avoid it.

I assume they can tag anything transmitting wrong info at the initial call up and fix it, and then ask the pilot if they can fix it.

The “problem” the Chief Counsel sites, of me supposedly sitting in another airplane listening to callsigns and trying to match them to a tiny screen, just doesn’t really exist anywhere but on the ground in a law office.

I’m simply not going to hit any of the dots. I don’t care what the data tag says they are.

Two pilot crew, MAYBE the other pilot is that bored once in a while to play match the heard callsign to the screen.

(Ultimately when you get to two crew, you’re probably also TCAS equipped and going to follow any RAs anyway.)

The lawyer letters are a crack up sometimes.

It’s almost as if they didn’t get the memo that ADS-B can not and MUST not be used as primary.

Maliciously setting it to naughty things, sure. Toss the book at ‘em.*

Not including two fields, one unchanged for true ID by tail, and a second for Flight number — that’s just bad engineering data design. Sigh.

Now you have to go downstream and create an override in every downstream system. Dumb dumb dumb.

Because Aviate, Navigate, Communicate... if I’m busy and it’s set wrong — it’s at the bottom of the in-flight priority list. The transponder setting is never an emergency.

* I’ve got screenshots of two of those. I get that they need a law to toss at the wayward pilots who do that. LOL.

 

[DA40FAN]

See also Angel Flight West's explanation -- https://support.angelflightwest.org/hc/en-us/articles/228386827-NGF-Call-Sign-Instructions

"If the N number in the ADS-B Out equipment CANNOT be changed by the pilot, then the pilot cannot use the NGF call sign and must use the N number."

 

[MuseChaser]

Caveat/confession.. I'm not real familiar with most of the boxes being discussed here.
Question... Why is the ability to get ADSB-In a consideration when choosing very expensive boxes, when you can build something that will give you ADSB-in traffic and weather just as well for just slightly over $100, or with WAAS GPS and AHRS for about $160...even if you're a technophobe?

If it's for the convenience of not having to connect an extra device and/or battery and you've got a LOT of money to pay for that convenience, OK.. I get it. If not... what are the other reasons?

Honest question.. already looking at adding a panel GPS nav, maybe a second com..currently flying with Stratus ESG for 1090 out, Stratux for ADSB-in, one nav/com/gs, audio panel, and iFly. Want to make sure I'm not missing something.

 

[DA40FAN]

I have ADSB weather and traffic on both my GNS530W and Ipad (GDL88 for the G530 and Stratus for the Ipad with Foreflight). I prefer the traffic display on the G530, which also has traffic aural call-outs, and, although it may not be make any difference, the fact that it is certified. Conversely, I prefer the weather on my Ipad because the display is much better and there are more features.

 

[FORANE]

Have you recomputed your weight and balance with the gdl88? That thing is a beast.

 

[WannFly]

That's interesting! I thought my panel was pretty unique. Let's see...

GNS-480
GMX-200
Sandel 3500 eHSI
SL-30 as NAV/COM2
STEC-20 + VSS
WX-900 Stormscope
SL-70R (and a panel-mounted SL-70 too)

and in the tail, a GDL-69 for XM weather and the GDL-90.

Well you got a few more stuff.

GDL 90 in the tail
SL 70
SL 15
480
GMX 200
SL 30
Century 2000 AP
Changed the gyro to dual G5 and got rid of the TC

 

[azure]

Caveat/confession.. I'm not real familiar with most of the boxes being discussed here.
Question... Why is the ability to get ADSB-In a consideration when choosing very expensive boxes, when you can build something that will give you ADSB-in traffic and weather just as well for just slightly over $100, or with WAAS GPS and AHRS for about $160...even if you're a technophobe?

If it's for the convenience of not having to connect an extra device and/or battery and you've got a LOT of money to pay for that convenience, OK.. I get it. If not... what are the other reasons?

Honest question.. already looking at adding a panel GPS nav, maybe a second com..currently flying with Stratus ESG for 1090 out, Stratux for ADSB-in, one nav/com/gs, audio panel, and iFly. Want to make sure I'm not missing something.

My reason is that I've not found any way to yoke-mount an iPad so that it doesn't obscure instruments that I want in my regular scan. So it goes on my knee, or in my lap. And I really don't want to have to look down at it, especially in IMC. Briefing an approach on the iPad, I have to do that, and it's distracting and disorienting. I like to do it as little as is absolutely necessary.

But I haven't totally ruled out that option, if the others are just very prohibitively expensive.

 

[azure]

Well you got a few more stuff.

GDL 90 in the tail
SL 70
SL 15
480
GMX 200
SL 30
Century 2000 AP
Changed the gyro to dual G5 and got rid of the TC

Other than the Sandel though, very similar! (Ok, different AP...)

How do you like the 480? People seem to either love them or hate them.

 

[chemgeek]

Caveat/confession.. I'm not real familiar with most of the boxes being discussed here.
Question... Why is the ability to get ADSB-In a consideration when choosing very expensive boxes, when you can build something that will give you ADSB-in traffic and weather just as well for just slightly over $100, or with WAAS GPS and AHRS for about $160...even if you're a technophobe?

If it's for the convenience of not having to connect an extra device and/or battery and you've got a LOT of money to pay for that convenience, OK.. I get it. If not... what are the other reasons?

Honest question.. already looking at adding a panel GPS nav, maybe a second com..currently flying with Stratus ESG for 1090 out, Stratux for ADSB-in, one nav/com/gs, audio panel, and iFly. Want to make sure I'm not missing something.

Mainly it's to get integration of traffic and weather with flight mapping on your GPS box, and/or reduction of cockpit clutter. Or, in the case of the NGT9000 you get a separate weather and traffic screen. This can be useful with small screen navigators like the GNS430W. The GPS can be used to display nav, the transponder to display traffic and weather. (The NGT9000 effectively has TWO screens.) The only cockpit clutter I have is my EFB, which can duplicate the NGT9000 traffic and WX display on a large map screen. Even my backup GPS, an AERA 510 with XM WX, is wired to ships power and the GNS430 on a permanent mount. The jury is still out for me re ADS-B weather and XM. The FIS-B feed has flaked on me a few times but not in IFR conditions. The XM has been rock solid. Neither is fast getting started up.

 

[azure]

Have you recomputed your weight and balance with the gdl88? That thing is a beast.

How so? 3.75 lbs is not exactly what I would call a "beast". Might affect the CG some so far back in the tailcone, but in the Cardinal that's not a bad thing... with someone heavy in the right seat I need ballast in the cargo anyway as the bird is quite nose-heavy.

 

[bnt83]

Have you recomputed your weight and balance with the gdl88? That thing is a beast.

88 is the size of a transponder with no display?

GDL90 is just over 5 pounds

 

[azure]

Apparently the GDL-90 is 5.2 lbs, not counting the mounting tray... I think this is a non-issue.

 

[WannFly]

Other than the Sandel though, very similar! (Ok, different AP...)

How do you like the 480? People seem to either love them or hate them.

I used to be pretty frustrated with it until I learned the way it needs to be handled. Now I don’t have to think twice and hate the fact that when it dies, there is no fixing for it.

 

[denverpilot]

My reason is that I've not found any way to yoke-mount an iPad so that it doesn't obscure instruments that I want in my regular scan. So it goes on my knee, or in my lap. And I really don't want to have to look down at it, especially in IMC. Briefing an approach on the iPad, I have to do that, and it's distracting and disorienting. I like to do it as little as is absolutely necessary.

But I haven't totally ruled out that option, if the others are just very prohibitively expensive.

Side window mount. Done right it will block very little view out of the window for say, the traffic pattern, but IMC it’s up and just off to the left (or right if you fly in the other seat) of the scan, and no head tilting downward needed to read it.

I hated the downward head tilt to the lap, and yoke mounting in turbulence whether with or without an AP is an exercise in reading w document that’s rocking back and forth. Perhaps somewhat violently. Dumb.

Have to get it up and off to the side. Or if you’re lucky enough to have a ton of panel space to rearrange things, make a gap and a clip in mount or whatever there.

The side window double suction cup (we’ll get to that in a second) RAM mount works great and moves better between airplanes and between left and right seats.

Double suction cup mount because, one will eventually let go and drop the whole rig on your wrist. And that hurts. Check them regularly. Hahaha.

Plus again, turbulence. The iPad will stay put better with two and the right short arms that articulate to get it perfectly out of the way but right in your field of view.

 

[FORANE]

How so? 3.75 lbs is not exactly what I would call a "beast". Might affect the CG some so far back in the tailcone, but in the Cardinal that's not a bad thing... with someone heavy in the right seat I need ballast in the cargo anyway as the bird is quite nose-heavy.

88 is the size of a transponder with no display?

GDL90 is just over 5 pounds

Apparently the GDL-90 is 5.2 lbs, not counting the mounting tray... I think this is a non-issue.

When there are 2020 compliant options on the market that weigh in at 60 gms, there's no way I would install one at almost 4 lbs. Bought an 88 and sold it rather than install it for that reason after realizing its heft. Of course my ship weighs in at 1,000 lbs empty; weight may be less of an issue for others.
5.2 lbs seems tremendously heavy; wonder why it is.

 

[azure]

Side window mount. Done right it will block very little view out of the window for say, the traffic pattern, but IMC it’s up and just off to the left (or right if you fly in the other seat) of the scan, and no head tilting downward needed to read it.

I hated the downward head tilt to the lap, and yoke mounting in turbulence whether with or without an AP is an exercise in reading w document that’s rocking back and forth. Perhaps somewhat violently. Dumb.

Have to get it up and off to the side. Or if you’re lucky enough to have a ton of panel space to rearrange things, make a gap and a clip in mount or whatever there.

The side window double suction cup (we’ll get to that in a second) RAM mount works great and moves better between airplanes and between left and right seats.

Double suction cup mount because, one will eventually let go and drop the whole rig on your wrist. And that hurts. Check them regularly. Hahaha.

Plus again, turbulence. The iPad will stay put better with two and the right short arms that articulate to get it perfectly out of the way but right in your field of view.

Thanks Nate, I will have to think about this. I hesitate to block any of the outside view, but if it can be easily removed for VFR ops (I assume it can since it's a suction cup mount, doh), then this might be a solution. Hmmm.

No I don't have any spare panel space (see avionics list above). The only thing that MIGHT work is a suction mount. (And a new iPad since mine's a 2... but that's much cheaper than anything certified.)

Then with iPad solutions, the question is whether Stratux TIS-B will continue to work next year...

 

[azure]

5.2 lbs seems tremendously heavy; wonder why it is.

I imagine increasing miniaturization is the reason most newer units are lighter... the GDL-90 is a decade or more older technology.

 

[John Collins]

Caveat/confession.. I'm not real familiar with most of the boxes being discussed here.
Question... Why is the ability to get ADSB-In a consideration when choosing very expensive boxes, when you can build something that will give you ADSB-in traffic and weather just as well for just slightly over $100, or with WAAS GPS and AHRS for about $160...even if you're a technophobe?

If it's for the convenience of not having to connect an extra device and/or battery and you've got a LOT of money to pay for that convenience, OK.. I get it. If not... what are the other reasons?

Honest question.. already looking at adding a panel GPS nav, maybe a second com..currently flying with Stratus ESG for 1090 out, Stratux for ADSB-in, one nav/com/gs, audio panel, and iFly. Want to make sure I'm not missing something.

I am quite happy using a portable for receiving and displaying weather. In the case of traffic, I don't believe in portables, there are way too many issues, high amongst them are antenna location, alerting algorithms, audio, lack of service indication, etc. So you are receiving tons of traffic, your close in TISB traffic only is broadcast by a single ground station and it assigned based on your bottom mounted ADS-B Out antenna, so a portable antenna in the cockpit is at high risk of not receiving the traffic you care about. It makes not a whit of difference if you are receiving from 10 ground stations simultaneously if you are not receiving from the one that is broadcasting the TISB for your aircraft, your portable receiver might not be receiving it and you have no way of knowing. In a portable, what is the method and algorithm used to alert you to close in traffic and what does it deem as "close in" and a threat? Is it simply distance and altitude and does not take into account the time to react. Is it evaluating climbing or descending or turning traffic? Does it call out the relative altitude, azimuth and distance so you can have your eyes outside and still use it to help locate threats?

Is a portable better than nothing, sure. If you just want to see irrelevant traffic and care less about traffic that is actually a collision threat and don't want to spend the money, go the portable route and you too can be fat, dumb, and happy. For me I want a certified system built into the avionics. I will still be fat and happy.

 

[Jim_CAK]

Caveat/confession.. I'm not real familiar with most of the boxes being discussed here.
Question... Why is the ability to get ADSB-In a consideration when choosing very expensive boxes, when you can build something that will give you ADSB-in traffic and weather just as well for just slightly over $100, or with WAAS GPS and AHRS for about $160...even if you're a technophobe?

If it's for the convenience of not having to connect an extra device and/or battery and you've got a LOT of money to pay for that convenience, OK.. I get it. If not... what are the other reasons?

Honest question.. already looking at adding a panel GPS nav, maybe a second com..currently flying with Stratus ESG for 1090 out, Stratux for ADSB-in, one nav/com/gs, audio panel, and iFly. Want to make sure I'm not missing something.

Like the others mentioned - it is a big plus having the traffic and weather on the panel. We have a small group that flys our plane but a few don’t use iPads. I fly with an iPad yoke mounted and I still prefer traffic and weather on the panel. There are no extra wires, no batteries to go dead, no iPads overheating. The downside is cost. For ADSB in and out we got the Lynx NGT9000. The integrated display was the key. The normal transponder is a box you key in a squawk code at the start of the flight and do not use. The Lynx adds another display which is great if you only have one of the smaller navigators. I leave the left side of the Lynx on the traffic screen and the right side on one of the weather pages.

 

[John Collins]

Yeah...you can throw thousands of dollars at ADS-B in if that makes you feel safer...I have no problem with that opinion, but don’t label us that use Stratus ADS-B in as viewing “irrelevant” traffic. I also use ForeFlight...and it DOES show ADS-B tower reception status, it also gives traffic alerts ....it calls out traffic within 1.8nm horizontally and 1200 feet plus or minus your altitude...clock direction and altitude are in the verbal alerts. If you are receiving 10 towers as you stated above, chances are you are receiving the closest to you..which will include TIS-B traffic in your location. A bottom mounted ADS-B antenna is always a good idea, but there are lots of us using portables .

How do you know you are receiving from the one and only one tower that is up linking your nearby TISB traffic? Were you aware that one and only one tower will be broadcasting your nearby TISB traffic? The tower just below you or closest to you is one that has a greater probability that it is shielded by the airframe. 1.8 NM is less than 20 seconds of warning for high speed converging traffic and may only be a few updates depending on the local radar coverage. I get traffic calls for high speed targets more than 5 miles under those circumstances. The indication of receiving from a tower is not an indication it is providing TISB for your aircraft or that your aircraft is inside a TISB service volume and receiving the TISB service. With my certified system, I get an indication that I am inside a TISB service volume and receiving the service. TISB will become less of an issue as more aircraft get equipped, but it will not go away. Adding a bottom mounted antenna is relatively inexpensive and helps in this regard.