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Collision avoidance systems


wlfpckrs

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Need for some guidance/feedback on the considerations for adding a CAS to my 2006 CTSW with a Garmin 396 GPS and Mode C transponder. I'm looking for the protection a CAS provides, but trying to keep a lid on the costs. Do any of you have experience with the Zaon units? I understand the higher-end unit can be hard-wired into the plane. Any tricks to installing it? TCAS. Mode S. ADS-B. What to do?

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I think the best option right now, if it's in your price range, is to install an ADS-B In+Out solution such as the Garmin GDL 88. As an ADS-B Out participant, you'll get full TIS-B traffic around your location, which will include anything the Zaon would pick up, as long as you are in the coverage area of an ADS-B ground station.

 

I have the Zaon XRX, and I find that it works just okay, not great. I often get false alarms (says there's traffic when there's not), and I've had a couple of instances of traffic getting too close for comfort before it detects it.

 

No traffic system will completely free you from remaining vigilant with visual scanning (there can always be birds, planes without transponders, etc.), but I think ADS-B is the most reliable option. And we'll all need it by 2020 anyway.

 

I got a quote on a GDL 88 recently. Installed in my CTsw, it was right around $6k. This was with the WAAS receiver option... if you already have a certified WAAS position source that can send data to the GDL 88, you'll save maybe $800-$1k.

 

-Russ

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.. if you already have a certified WAAS position source that can send data to the GDL 88, you'll save maybe $800-$1k.

 

-Russ

 

The quoted phrase raised a couple of points. I'm no expert and have been researching the ADS-B situation recently. Here is my understanding from online talks with Dynon and people who seem knowledgeable on some other forums.

 

1. For now, any GPS that will communicate with your ADS-B Out device is legal and will work. It is not quite as accurate as an IFR certified device and ATC can tell that. In 2020 it must be IFR certified.

 

2. The FAA does not specify WAAS, rather it calls for IFR certified. I fully agree that there are no new GPS receivers that are IFR that are not always WAAS, I'm only repeating what I understand about the regs so that we don't let wording confusion interfere with our choices.

 

I'm not posting this to be nit-picking but rather because the ADS-B field sometimes seems obtuse and anything to keep things clear might help.

 

 

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I think the best option right now, if it's in your price range, is to install an ADS-B In+Out solution such as the Garmin GDL 88. As an ADS-B Out participant, you'll get full TIS-B traffic around your location, which will include anything the Zaon would pick up, as long as you are in the coverage area of an ADS-B ground station.

 

That is the Cadillac solution, but there's a whole lot of dollars between a Zaon and a Garmin $6K ADSB In+Out full install! You could also just get a mode S transponder and get much better traffic than the Zaon gives you. A Garmin GTX 330 is about $3500. If you could get an LOA you can get cheaper mode S boxes from Trig, etc down in the $2000 range. For an extra $1000 the GTX 330ES does ADSB out as well...and you might be able to upgrade a 300 to 330ES later, I can't remember the skinny on that.

 

Since the ADSB Out requirement doesn't kick in until 2020, you'd get good traffic alerting and buy yourself several years to let ADSB prices come down and features come up. ;)

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That is the Cadillac solution, but there's a whole lot of dollars between a Zaon and a Garmin $6K ADSB In+Out full install! You could also just get a mode S transponder and get much better traffic than the Zaon gives you. A Garmin GTX 330 is about $3500. If you could get an LOA you can get cheaper mode S boxes from Trig, etc down in the $2000 range. For an extra $1000 the GTX 330ES does ADSB out as well...and you might be able to upgrade a 300 to 330ES later, I can't remember the skinny on that.

 

Since the ADSB Out requirement doesn't kick in until 2020, you'd get good traffic alerting and buy yourself several years to let ADSB prices come down and features come up. ;)

 

 

For me I have to fly ~ 200 miles towards LA or San Fran before I get TIS. I also have to cross the Sierra Nevada before I would be able to get much ADSB in my airspace. Oakland's radar can't see this side unless you are above 13,000'. On the other hand most of the traffic I see comes from my Zaon.

 

It will be a few years before ADSB is very helpful in some mountainous areas.

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It will be a few years before ADSB is very helpful in some mountainous areas.

 

The more planes that have ADS-B OUT on a common frequency, the more traffic you'll see. 1090ES is going to be the defacto standard. If we buy UAT 978 ADS-B OUT, we'll rely on a ground station to retransmit their position, and as you indicate, this will be a problem in the mountains. We need UAT for weather in, but 1090ES seems like the frequency to get most traffic in.

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A buddy of mine responded with this. Any thoughts?

 

For roughly the price of the Zaon device and a mode S xpndr, you guys could probably have the CT retrofitted with the Dynon SkyView system (now standard equipment in the Flight Design aircraft). Why you ask??????

 

Well let me count the ways....... First check this link

 

http://www.dynonavionics.com/docs/SkyView_Features.html

 

The package includes better everything than what's in the plane right now plus it includes a mode S xpndr !!! In addition Dynon offers an extremely well priced ADS-B "IN" receiver that will give you ADS-B weather, airport data and TIS-B traffic as per

 

http://www.dynonavionics.com/docs/news_technology_preview.html.

 

This requires the Dynon mode S xpndr (included in the SkyView system) which is apparently the only xpndr that meets the requirements

 

To save a bit you can select the 7" SkyView panel for the engine display and backup PFD.

 

The package includes and autopilot and a gps sooooooo............

 

The 396 could be viewed as a "backup" nav instrument, the current Garmin xpndr could be surplused into the homebuilder market along with the D100 system/sensors. You'd almost be guaranteed the lowest cost for mode S/ADS-B with traffic, you'd have the latest greatest with synthetic vision/moving map, multi waypoint flight planning etc etc.

 

Plus you could drop the XM weather contract for even more savings......

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A buddy of mine responded with this. Any thoughts?

 

For roughly the price of the Zaon device and a mode S xpndr, you guys could probably have the CT retrofitted with the Dynon SkyView system (now standard equipment in the Flight Design aircraft). Why you ask??????

 

Well let me count the ways....... First check this link

 

http://www.dynonavionics.com/docs/SkyView_Features.html

 

The package includes better everything than what's in the plane right now plus it includes a mode S xpndr !!! In addition Dynon offers an extremely well priced ADS-B "IN" receiver that will give you ADS-B weather, airport data and TIS-B traffic as per

 

http://www.dynonavionics.com/docs/news_technology_preview.html.

 

This requires the Dynon mode S xpndr (included in the SkyView system) which is apparently the only xpndr that meets the requirements

 

To save a bit you can select the 7" SkyView panel for the engine display and backup PFD.

 

The package includes and autopilot and a gps sooooooo............

 

The 396 could be viewed as a "backup" nav instrument, the current Garmin xpndr could be surplused into the homebuilder market along with the D100 system/sensors. You'd almost be guaranteed the lowest cost for mode S/ADS-B with traffic, you'd have the latest greatest with synthetic vision/moving map, multi waypoint flight planning etc etc.

 

Plus you could drop the XM weather contract for even more savings......

 

 

The Dynon Mode S transponder is not included with Skyview, it is a separate product designed to integrate with Skyview...Dydnon XPDR

 

From Aircraft Spruce, the cheapest 7" Skyview system is about $2500 plus $1175 for ADAHRS, plus GPS antenna, plus engine monitoring probes, plus the XPDR if you want to add that....plus installation. I'm not sure it's as cheap a solution as you think, when you add in everything you need to make it a full-featured system.

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If we buy UAT 978 ADS-B OUT, we'll rely on a ground station to retransmit their position, and as you indicate, this will be a problem in the mountains. We need UAT for weather in, but 1090ES seems like the frequency to get most traffic in.

 

This is addressed by having a "dual-link" receiver, and is why we are seeing a number of them coming to market. The GDL 88, as an example, transmits ADS-B Out information only the 978MHz UAT frequency, but can receive on both 978MHz and 1090MHz. So even if you aren't in range of a ground station, you will still be able to see traffic that is broadcasting on 1090MHz by picking up their transmissions directly.

 

I wouldn't install anything that doesn't have dual-link reception, for exactly this reason.

 

-Russ

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"I often get false alarms (says there's traffic when there's not)..."

 

Struck me as funny. Isn't this the reason you get a CAS unit - to detect traffic you can't/don't see?

 

Right, but if it is calling out traffic that isn't actually there, then it is "crying wolf." The pilot is then likely to regard future warnings as less credible.

 

I find the false warnings usually happen when I'm overflying an airport (well above it) and there is traffic in the pattern or on the ground with their transponder on. The Zaon should be able to reject these targets based on the Mode C altitude info, but for whatever reason it often doesn't. Instead it shows them within a few hundred feet of my altitude.

 

-Russ

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Right, but if it is calling out traffic that isn't actually there, then it is "crying wolf." The pilot is then likely to regard future warnings as less credible.

 

I find the false warnings usually happen when I'm overflying an airport (well above it) and there is traffic in the pattern or on the ground with their transponder on. The Zaon should be able to reject these targets based on the Mode C altitude info, but for whatever reason it often doesn't. Instead it shows them within a few hundred feet of my altitude.

 

-Russ

 

How do you tell a false alarm from one you just can't find visually?

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How do you tell a false alarm from one you just can't find visually?

 

To be sure, this can happen. But I know for certain I've gotten a number of truly false alarms.

 

Usually it's because I'm using flight following, in which case ATC would let me know of any important traffic to look for. The other scenario is when I'm not doing flight following, but listen in on the CTAF of airports I'm flying near to stay aware of traffic in the area. A couple of times I have had the Zaon start flashing a traffic warning (i.e., apparently very close proximity, possibly requiring evasive action) when it was clearly the two planes flying in the pattern 3000 feet below. Of course a traffic warning always pops my eyes right open puts my head on a swivel and I search intensively for the supposed traffic. But after this happens a few times and it turns out clearly to be a ghost, it gets a little tiresome. :)

 

Probably there's no such thing as a perfect CAS, and any of them have at least some chance of giving false positives and false negatives. I still use my Zaon... I just wish it gave fewer false indications.

 

-Russ

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This is addressed by having a "dual-link" receiver, and is why we are seeing a number of them coming to market. The GDL 88, as an example, transmits ADS-B Out information only the 978MHz UAT frequency, but can receive on both 978MHz and 1090MHz. So even if you aren't in range of a ground station, you will still be able to see traffic that is broadcasting on 1090MHz by picking up their transmissions directly.

 

I wouldn't install anything that doesn't have dual-link reception, for exactly this reason.

 

-Russ

Will the high fliers have UAT in? They don't need it for weather as they are getting weather other ways. If they don't have UAT in, they will not see you directly in this scenario, even if you see them.

 

For others - keep in mind that when we say Mode S Transponder, not all have Extended Squitter (ES). Probably they all will some day soon, but in the meantime, it doesn't hurt to verify that the one you want has ES.

 

 

 

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Will the high fliers have UAT in? They don't need it for weather as they are getting weather other ways. If they don't have UAT in, they will not see you directly in this scenario, even if you see them.

 

Not sure if the big boys will have dual link or not. But in general, won't they be on an IFR flight plan and therefore always be in communication with ATC, and thus be getting traffic advisories that way?

 

-Russ

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Not sure if the big boys will have dual link or not. But in general, won't they be on an IFR flight plan and therefore always be in communication with ATC, and thus be getting traffic advisories that way?

 

-Russ

 

I guess I was answering in response to CT's discussion about mountain flying. The Citations, King Airs and so forth will almost always be IFR, but many airports with no tower will have an approach that is not covered all the way down to the ground by radar or a ground station. They could be on a visual approach while you are VFR. So, the Citation and you could both be flying into an airport and if he is on 1090ES and you are on UAT, I don't think you will see each other air-to-air.

 

 

 

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