Portable collision avoidance systems

Matthew

Matthew

Touchdown! Greaser!
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Matthew
On a system like Zaon ( http://www.zaon.aero/ ), or other brands ->

Does your own transponder cause any interference? How does it discriminate your own transmission from someone else nearby? Can your own transponder cause a false alarm?

A guy in my glider club got a Zaon after a close call. Now he's thinking about adding a transponder of his own and these questions came up.
 
No, your own transponder does not interfere with the Zaon. It picks up the strongest signal and ignores it. Zaon promises 100% no false positives. I and our glider club use them in our transponder equipment gliders. I find it an extra set of eyes in the busy airspace around Philadelphia. Of course it does not help with a non-transponder equipment glider. :wink2:


Matthew said:
On a system like Zaon ( http://www.zaon.aero/ ), or other brands ->

Does your own transponder cause any interference? How does it discriminate your own transmission from someone else nearby? Can your own transponder cause a false alarm?

A guy in my glider club got a Zaon after a close call. Now he's thinking about adding a transponder of his own and these questions came up.
Click to expand...
 
magicj said:
No, your own transponder does not interfere with the Zaon. It picks up the strongest signal and ignores it. Zaon promises 100% no false positives. I and our glider club use them in our transponder equipment gliders. I find it an extra set of eyes in the busy airspace around Philadelphia. Of course it does not help with a non-transponder equipment glider. :wink2:
Click to expand...


Thanks - perfect. The guy added a Zaon to his glider after a too-close call with an airplane. Now he's wanting to add a transponder so he can at least be more visible to anyone else with a traffic system. I hadn't thought about just how it works, but I know there are many people who already have the Zaon in a xponder equiped plane.
 
Matthew said:
Thanks - perfect. The guy added a Zaon to his glider after a too-close call with an airplane. Now he's wanting to add a transponder so he can at least be more visible to anyone else with a traffic system. I hadn't thought about just how it works, but I know there are many people who already have the Zaon in a xponder equiped plane.
Click to expand...

I have one, it works well ... most of the time. Am at a training intensive field, a number of times the students forget to activate their transponder on takeoff.
 
OK - next question. If the Zaon rejects the strongest signal because it assumes it is from the same aircraft, what about the case where the aircraft does not have its own xponder? It would defeat the purpose of having the warning system if it didn't tell you about the plane closest to you that just remembered to turn on his xponder.

I guess there are a lot of ways that the system won't work perfectly, but I mainly wanted to understand how it doesn't treat your own xponder as traffic.
 
I've been flying with the Xaon XRX for a year now. The only time I thought it might have been giving me a false positive, my mode S TIS readout was also painting the target so I have to believe it was something I couldn't see (and at .3 miles it was darned scary that I couldn't).

The PCAS has a special mode to detect that you don't have your transponder on (or you don't have one). Once it decides you don't have a transponder, it uses it's internal altimeter rather than relying on the local mode C interogation to do the relative altitude computations.

It's not only the strongest signal that it locks on to as "My Transponder" but it also has to be at the same altitude.
 
Collision avoidance systems are a great second set of eyes but like Clint Eastwood said "A man has got to know his limitations". The portable units aren't quite as good as the built in system and both have limitations; the biggest being line-of-site. With the portable there are more blind spots so never rely on them to give you all of the traffic conflicts. Way better than just mark-20 eyeballs.
 
Zaon promises 100% no false positives.
Click to expand...

I can absolutely say without any hesitation that if Zaon promises that, it's a very hollow promise.

I've had hundreds of them, as well as a lot of missed alerts (times it should have alerted, but didn't), with conflicting traffic.

The Zaon is a very poor substitute for TCAS, but then TCAS isn't a possibility in most light airplanes due to cost and installation. PCAS is very limited in what it can do, and in the information it provides. One needs to always keep squarely in mind the fact that there's a lot of light traffic out there that's not talking or squawking.

Never look for traffic with the radio,or with a gimmick. The PCAS is just that. Use it as a useful partial-supplement, but don't consider it anything more. It may alert you to some traffic, but can quickly lull you into a bad place if you believe it's anything more.
 
I wouldn't worry so much about false positives, as missed alerts. False positives are rare and won't kill you. Depending on where you fly, there can be lots of missed alerts. Still and yet, I'm happy to have mine acting as another set of eyes.
 
Baron2PG said:
Collision avoidance systems are a great second set of eyes but like Clint Eastwood said "A man has got to know his limitations". The portable units aren't quite as good as the built in system and both have limitations; the biggest being line-of-site. With the portable there are more blind spots so never rely on them to give you all of the traffic conflicts. Way better than just mark-20 eyeballs.
Click to expand...

The Zaon XRX cabin blind spots was the major reason for me to choose the Monroy ATD-300+ The ATD-300+ uses an external directional antenna that eliminates the blind spots. On final it points traffic behind or ahead of me that the Zaon was unable to detect. No doubt that an external antenna is better than one inside the cockpit. You can see the ATD-300 at:
http://www.monroyaero.com/ATD300Webpage8.pdf

José
 
We've had a Zaon XRX for a couple years. For the last few months, it has been giving false alerts on every flight. Recycle it, move it, unplug the power cable, nothing really fixes it. It's helpful most of the time, but the false alerts are a PITA. I also never trust that a blank screen means an empty sky because it also misses traffic.
 
On the Garmin 430W TIS I am frequently alerted to avoid crashing into myself while practicing steep turns and the like. :D
 
> Does your own transponder cause any interference? How does it discriminate
> your own transmission from someone else nearby?

No. Transponders are nominally, 200 watts radios. Signal strength drops as
the square of the distance ... so it is pretty easy to determine which transponder
(yours) should be ignored.

> Can your own transponder cause a false alarm?

Yes. This is exacerbated if you do not [re]calibrate the unit. It is trivial to
[re]calibrate.

>> Zaon promises 100% no false positives.

Really? I did a quick scan of their website and did not notice such a
claim. If they have indeed, made such claim, it is irresponsible of them.

My unit is calibrated. My false rate is acceptably low. Most times it sees
traffic before I do.

That said, their tech support organization (3 years ago) was apparently
illiterate. I sent them a very specific problem description that described
the exact defect in a Garmin interface cable they shipped. They sent me
two [2] more cable shipments that duplicated the original defect - Grrrr.

Knowing what I know now, would I buy it again? Yes.
 
Last edited:
Their service center is about five miles from my house. My only problem was addressed immediately and courteously. I too see a false alarm from time to time, but not often.

rainsux said:
> Does your own transponder cause any interference? How does it discriminate
> your own transmission from someone else nearby?

No. Transponders are nominally, 200 watts radios. Signal strength drops as
the square of the distance ... so it is pretty easy to determine which transponder
(yours) should be ignored.

> Can your own transponder cause a false alarm?

Yes. This is exacerbated if you do not [re]calibrate the unit. It is trivial to
[re]calibrate.

>> Zaon promises 100% no false positives.

Really? I did a quick scan of their website and did not notice such a
claim. If they have indeed, made such claim, it is irresponsible of them.

My unit is calibrated. My false rate is acceptably low. Most times it sees
traffic before I do.

That said, their tech support organization (3 years ago) was apparently
illiterate. I sent them a very specific problem description that described
the exact defect in a Garmin interface cable they shipped. They sent me
two [2] more cable shipments that duplicated the original defect - Grrrr.

Knowing what I know now, would I buy it again? Yes.
Click to expand...
 
I went as safety pilot in a plane that had a small unit. I wish I never flew that day, I was upset by how many times it showed there was traffic near us that I COULD NOT SEE. Frustrating.
 
A false positive is technically impossible. The XRX needs to be receiving a transponder response in order to display it. It won't manufacture one out of nothing. If by false positive you mean that the XRX is possibly displaying your own aircraft as a target, then there are setting tweaks for that - among them is an adjustment of the suppression settings that help it to eliminate your own transponder.

Most of the knocks I've ever heard of the XRX are from users who haven't called Zaon support. If it's not doing something quite right, I'd recommend to a) calibrate it, and if that doesn't help then b) call support.

On a few occasions, the XRX may not deliver the goods as intended. Heck, it's technology and when put in an environment containing other variables there's always a chance of that. But by and large most people that fly with an XRX won't fly without it!

Does it replace a good lookout, radio calls, or other means of traffic avoidance? NO!!!!! Does it provide another option for those whom a full-active TCAS system is not a possibility? Pleasantly, yes.

Full disclosure: I was a PCAS advocate before my TV life bringing PCAS to Canada as it's national distributor and was the author of "Close Calls," a monthly column which I started after a mid-air collision occurred close to home. Also, Zaon Flight Systems was a sponsor of The Aviators for it's first 2 seasons. My comments aren't intended to sell units, but rather to address some of the concerns I read in this thread and share some of the information I've learned as something of an expert on the XRX.

As I used to say in the column, Fly Safe(r).

Anthony
 
AnthonyNalli said:
A false positive is technically impossible.
Click to expand...

If that is true, then I have surely been lucky. My Zaon often shows other aircraft superimposed over top of me on the 496 for extended periods. Same altitude, same direction and same position. Either a stealth plane is often following me, or my zaon is doing the impossible. Perhaps I post too much in SZ and Homeland Security is following me.

My Zaon was in the plane when I bought it so I never read the warranty but I may have to contact them to see what they say.
 
JOhnH said:
If that is true, then I have surely been lucky. My Zaon often shows other aircraft superimposed over top of me on the 496 for extended periods. Same altitude, same direction and same position. Either a stealth plane is often following me, or my zaon is doing the impossible. Perhaps I post too much in SZ and Homeland Security is following me.

My Zaon was in the plane when I bought it so I never read the warranty but I may have to contact them to see what they say.
Click to expand...

Before I went with the Monroy ATD-300 I tried a Zaon XRX that my hangar neighbor was selling for $600. It did the same thing as false positives. I found they came from my own transponder after I switched it to STBY. To reduce the problem you have to recalibrate the unit in-flight. Calibrating it in a hangar is what gives you most of false positives and if you move it from one location to another. The ATD-300 requires no calibration and I do not get false positives with it. However it does requires a belly mounted external directional antenna.

José
 
"To reduce the problem you have to recalibrate the unit in-flight"

And how do you do that ?
 
Scrabo said:
"To reduce the problem you have to recalibrate the unit in-flight"

And how do you do that ?
Click to expand...

Same way as on the ground. Just set the autopilot on.

When you do it in a hangar the onboard transponder signal levels in the cockpit are higher than when you are in-flight. This is due to the multiple reflections in a hangar that does not happens in flight. Thus the XRX sees a weaker onboard transponder signal in-flight and think it is traffic. And that is when you get the false positives. This is not a 100% fix because the signal levels are also affected by your hand proximity to the unit.

José
 
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