Zaon XRX PCAS issues

[VMC-on-top]

I recently bought a second hand Zaon XRX PCAS for using with my Garmin 496.

The display on the GPS is excellent and very clear, however, I've had a number of relatively minor issues with it recently and wondered if anyone else using the same, had experienced the same.

Primary problem is "ghosting" ie yesterday, I was tootling along in VMC, 30k vis and had an aircraft on the display directly behind me, then slightly to the right, then left (less than a mile each time), sometimes 1200ft below, sometimes above.

Further, it didn't seem to pick up aircraft in the circuit when I got back - I accept this could be that aircraft in the circuit didn't have their transponders on etc.

FInal issue is the relative position of aircraft to me. Most recently, I had a warning of aircraft approaching, about 30 degrees off dead centre, similar height. The warning flashed up as being dead ahead, then off to the right, then off to the left (by up to a mile each time) etc.?

Are these problems "normal" or is it down to the positioning of the unit on the dash? I fly a PA28 with a split windscreen, therefore a strip of metal down the middle of the screen. Is it simply a case of positioning as far away from that as possible?

Would be interested to hear of others experiences.

[Oldpilot55]

My experience, based on perhaps a dozen flights, is very similar. False and erratic returns are fairly common. For example I always seem to get a return when in the area of a disused airfield. At the time I would normally be talking to our local LARS and they have not reported any traffic.

On the positive side when I get a steady signal it does tend to be a positive return from traffic.

There is still a lot of traffic out there that do not or cannot use transponders like some microlights, homebuilts and most gliders.

Overall I am happy with it and would rather fly with than without it. Its an aid but not a perfect aid.

[Red Chilli]

Could be a weak signal from your own transponder. If your own xpndr output is low then the unit thinks it's another aircraft a short distance away (I've spoken with Zaon), intermittment problems may suggest wiring contacts/aerial issue - worth checking, I had this same fault which is now sorted

[SNS3Guppy]

Make sure the unit is the specified distance from the aircraft structure, and that it's oriented correctly, and level.

In my experience, the Xaon units are worth something, but not very much, and experience plenty of false warnings, as well as numerous misses of traffic. It's not TCAS, so don't expect it to perform the same.

It's better than nothing, but remember...nothing takes the place of your own eyes.

[IO540]

My very limited experience of the ZAON £1000 box is that it does what the OP has described.

No idea how one gets around it.

It is the price you pay for paying £1000 and not £15000

[wigglyamp]

TCAS costs

IO-540, why pay £15K when you can have a Garmin GTS800 or an Avidyne TAS600 supplied, fitted and certified for around £10K (+ VAT of course).
For this, you get an active interrogating traffic system with top and bottom antennae to reduce screening of the target, which will display on your Garmin GNS430/530 or other multi-function display and give you audio call-outs of target bearing and height.
PM me for more info.

[SNS3Guppy]

Interesting. When we had this conversation last year and I wasn't impressed with the Xaon unit, I heard every reason under the sun why that observation was wrong. One might have thought that I'd badmouthed the holy trinity.

Those same voices aren't rising in defense of the Xaon unit now.

http://www.pprune.org/private-flying...e-systems.html

[Rod1]

I have the MRX, Very happy with it, but I can make it detect a “ghost” in a number of ways. Easy to solve on mine, may not be applicable to the XRX. There are several pilots on this forum who have had very positive experiences with their XRX units. I hope to test one of the new units “power Flarm” in the near future (around £1300 ish).

Rod1

[Fuji Abound]

Interesting. When we had this conversation last year and I wasn't impressed with the Xaon unit, I heard every reason under the sun why that observation was wrong. One might have thought that I'd badmouthed the holy trinity.

Possibly because comment is based on the usual irrational and unsubstantiated observation.

Have you actually run one of these units alongside TAS?

Are you certain you know the "ghost" traffic is "ghost" traffic?

How have you actually assessed for any reasonable period of time that these units are beset with an unreasonable number of errors?

[Spendid Cruiser]

Are you certain you know the "ghost" traffic is "ghost" traffic?

If the XRX has the same issues as the MRX, then in my experience, ghost traffic is pretty obvious with repeated alerts for something 0.5nm away.

As the previous poster stated, it is invariably because the host's transponder signal is a bit on the weak side and so confuses it with a threat. Never had a problem when flying the Cub but many problems in the Seneca. Turn the transponder off and see if they disappear.

[SNS3Guppy]

Have you actually run one of these units alongside TAS?

Are you certain you know the "ghost" traffic is "ghost" traffic?

What is a TAS?

If you mean TCAS, yes. If you mean radar, yes. If you mean something else, then you'll have to explain.

Am I certain the traffic is ghost traffic? Yes; particularly after using infrared and night vision to search in the same location as the traffic indicated on the Xaon unit, as well as tracking and updates with threat radar.

How have you actually assessed for any reasonable period of time that these units are beset with an unreasonable number of errors?

Depends what you mean by any reasonable period of time. If you mean 20 or so units over about eight months and several hundred flight hours, yes. If you mean something else, probably not.

Possibly because comment is based on the usual irrational and unsubstantiated observation.

Oh really? Pray tell.

Turn the transponder off and see if they disappear.

That was certainly done, as well as the involved assistance of several expert avionics technicians. No improvement.

[Fuji Abound]

My experience is different over a similar number of hours. Based on your posts in the last thread I don't believe you were able to test the unit properly. A war zone with intermittent radar painting is probably not a very representative environment. If there is no ground based radar and transponders are switched off the unit will not work. They will no more work with ground based radar and transponders turned off.

It's very VFR presently, operating under VFR...but night, dark, few references, and a LOT of traffic, much of which isn't reporting, much of which can't. Simply being VFR means very little...because a VFR night here is still hard instrument conditions.

TAS - try a Google search, or perhaps you need a little help.

[SNS3Guppy]

I wasn't conducting a clinical observation of the Xaon PCAS. I was using it operationally, in a high-density traffic environment. All aircraft were squawking with a transponder. Nearly all operations were conducted at night, and radar was in use.

When I stated that much of the traffic wasn't reporting, it was because much of the traffic was unmanned, and much didn't use voice capability. Many of the aircraft used other means of communication which will not be discussed here, but which was available to ATC, but not to me (also for reasons that need not be discussed). The area was a combat zone, not a war zone, which has no impact nor bearing on the ability of the PCAS to do it's job.

The PCAS was used in numerous aircraft in numerous locations and conditions, with substantial traffic, in an environment very conducive to observation of it's function. Specialized equipment was available to see areas where traffic was identified by the PCAS, and verify that the traffic was indeed there or not there, and that equipment was operated by very experienced specialists who were amazingly good at what they did.

Now as I said, I didn't undertake the mission to test the PCAS. It was installed as an expedient field-procurement, and while it did have numerous false warnings, I did give positive hits which were immensely useful. I operated in an area where numerous threats existed. From a pilot's perspective, in my opinion, the biggest threat wasn't ground fire or other concerns, but the potential for a mid-air. I was interested in anything which provided additional traffic information, regardless of the source. With numerous resources available, the PCAS was but one reference.

The Xaon unit displayed numerous false targets, sometimes proving to be a distraction. In some cases where I could verify a false indication, it proved little more than a distraction. In other cases the distraction interrupted other activities while I verified what was being received, and it caused problems. I did have the PCAS alert to traffic which wasn't reported by ATC, which had been assigned to our airspace block by other entities, without any communication to local control or to us...and a certain amount of traffic in those areas operates autonomously. For these and other reasons, I was always well aware of the traffic information, and always included the information in my scan, and took it seriously. It had many false hits, but also provided useful information that sometimes wasn't available from other sources.

In general, the PCAS did provide some useful information, but also distractions, and did display a fairly high false-positive rate with failures. Transponder strength was addressed, as well as positioning, and onboard equipment was considered, and tested.

While I appreciate that you've had different experiences, you have no reason to discount my own. Certainly anyone considering spending the money to put one of these in their Cessna 172 shouldn't consider any available report. Perhaps you've had a good experience and feel threatened if a report of poor performance devalues the money you've invested. Perhaps you're personally invested in your PCAS. I have no idea. Perhaps you even sell them. No matter. That you don't like the fact that the units were observed to perform underpar means little. The units did perform fairly poorly, and this is fairly noted. By all means, publish your good report, and let others who read both decide for themselves.

TAS - try a Google search, or perhaps you need a little help.

Okay. Googled it. Nothing of value returned...unless you want to talk about "The American Spectator," "The Absolute Sound," "Texas Accessibility Systems," "Tactical Archery Systems," "TAS Turkish Restaurant," "The Animated Series," Tasmania Ferry Services," "Tata Administrative Services," "Tasmania," "Turbine Air Systems," "The American Statistician," or any number of other things that were returned.

I get it. You don't want to answer the question, and would prefer to be difficult. Good enough.

[Fuji Abound]

Mr Guppy

I agree. It is important to compare and contrast reports.

For me it stretches creditability that anyone would operate an aircraft in a combat zone testing equipment which was unapproved and, in the EU at any rate, illegally installed. I don’t understand why you so regularly seek to impress us with your encounters with combat zones, small arms fire and the like. In my experience those involved in such arenas prefer to avoid talking about their experiences. For me, to be blunt, I think you have a fanciful imagination. Your posts would be more creditable if you did not allow your imagination to run riot.

I accept that on this forum and elsewhere there have been reports of ghost encounters using Xaon. Sometimes these reports rely on the traffic having not been visually acquired. I have yet to have a ghost encounter with TAS. I have however thought I have had a number. The last that comes to mind suggested traffic at a similar height at a range of about five miles. It was uncanny; pretty much as we turned the traffic turned, holding and maintaining station. We both looked and we never saw the traffic. Out of interest I asked AT if they had anything on radar. Sure enough they did, although even they seemed a little bemused as to why the traffic was not talking to them and had not been assigned a squawk.

The traffic was real. It demonstrated once again how late we often visually acquire traffic, assuming that is we ever see the traffic. I can recount numerous cases of traffic on TAS that has come very close and yet was never seen.

See and avoid doesn’t work. OK, that is a sweeping statement. In good visibility with relatively slow moving traffic it has a chance. In poor visibility with faster traffic the chances are poor. The FAA among others has conducted some interesting research – it is available on the internet and worth a read if this topic is close to your heart. In reality it is the big sky that keeps us safe most of the time.

As irrational as it maybe I like the idea of knowing about any traffic that gets really close. For me a relatively cheap unit that was able to warn me about traffic that was too close for comfort, even if sometimes those warnings were spurious, is a worth while investment. If the vast majority of those warnings were spurious I would conclude it was more trouble than it was worth. I don’t believe form my own experience with the Xaon that is remotely close to being the case.

For those reasons I have one, and use it whenever I fly without TAS.

(Ducks the incoming small arms fire. )

[SNS3Guppy]

For me it stretches creditability that anyone would operate an aircraft in a combat zone testing equipment which was unapproved and, in the EU at any rate, illegally installed.

I operated the equipment, which was legally installed, because it was there to be used, operationally, on the job. Period. I didn't travel to those locations to see how that equipment worked, and I didn't install it.

The equipment was installed, with approvals, professionally, and was very legal. You should perhaps stick to the facts.

I don’t understand why you so regularly seek to impress us with your encounters with combat zones, small arms fire and the like. In my experience those involved in such arenas prefer to avoid talking about their experiences.

I couldn't care less if you're impressed, as it's really quite irrelevant as to whether the Xaon unit works or not. Nor is it relevant to my paycheck. At a time when I was furloughed and without work, I spent the year in a location that involved certain hazards, and whether you like it or not is really unimportant. I was my paycheck, and not yours. I won't discuss the work I did there, but I'm more than happy to discuss unrelated information, such as the Xaon PCAS. I'm not going to discuss mission equipment or my role in that location. There's nothing classified or secret about a minor piece of avionics equipment, however, that can be purchased from Sporty's Pilot Shop.

Have you found people who avoid talking about the Xaon PCAS, then?

Have you ever worked in such an environment yourself? Doubtful.

For those reasons I have one, and use it whenever I fly without TAS.

You use your PCAS whenever you don't have Tactical Archery Systems available to you? Whatever floats your boat.

Perhaps when you say TAS you mean some type of traffic alert system, such as TCAS. If that's the case, then PCAS is a traffic alert system, albeit not a very good one.

[Fuji Abound]

I couldn't care less if you're impressed, as it's really quite irrelevant as to whether the Xaon unit works or not.

This is really getting silly now. If you dont care whether I am impressed or not and its not relevant to the discussion (which I agree it is not) then stop keep trying to impress us with your small arms encounters etc and cloak and danger nonesense about what you can and cant say. Although it was amusing at first, honestly, we are not interested or impressed and it just makes you come across as a complete pr*T, which is a shame, because you just might know something about some of the subjects we discuss.

As to approved traffic systems as far as I am aware these are all distinguished from PCAS because they actively interogate other aircraft's transponders. Moreover, so far as I am aware, amoung the other requirments to be certified they have dual antennas to avoid some of the issues discussed on this thread. TAS does not however include the software to produce a resolution advisory. If you are interested in a more detailed understanding of these systems and how they work both Garmin and Avidyne employ the same hardware option on their G1000, Integra R9 and earlier Avidyne glass systems used by Diamond, Cirrus, Mooney and others.

As to PCAS, in Europe it is illegal to hard wire these systems into an aircraft because they are not certified for panel mount by the regulators. Many people do, but that is another matter. If the unit is plugged into an adapter socket then it is not hard wired. I doubt any regulatory authority would certify either of these untis to be hard wired into an aircraft but who knows what might or might not be allowed (particularly in a combat zone - sorry I just couldnt resist. but I am only joking).

[SNS3Guppy]

As to PCAS, in Europe it is illegal to hard wire these systems into an aircraft because they are not certified for panel mount by the regulators. Many people do, but that is another matter. If the unit is plugged into an adapter socket then it is not hard wired. I doubt any regulatory authority would certify either of these untis to be hard wired into an aircraft but who knows what might or might not be allowed (particularly in a combat zone - sorry I just couldnt resist. but I am only joking).

The work was done as an FAA field approval, major repair or alteration. Everything was legal. That's all you really need to know.

[Fuji Abound]

I am interested that the FAA approved the installation.

Whilst we might not like it the theory behind what gets hard wired into the panel or doesnt is safety. Are the electronics sufficiently robust and resistant to short circuits and fire, do they represent a physical hazard in the cockpit or impinge on the pilot operating the controls or his view, and does the equipment do what is intended. I can see how you might mount the more basic version of the Xaon in the panel (and indeed Zaon even sell a kit) but I have no idea how you would panel mount the XRX given its shape.

Zaon offer some guidance in their installation manual and discuss whether the FAA consider the installation a major or minor mod. Clearly you might persuade an A&P that the Zaon is a minor mod or the FAA that it is a major mod. I very much doubt you would persuade our dear CAA on either count. Having persuaded either the issue then arises what aerial(s) is / are used, where it is / they are placed and what effect other avionics and panel screening will have on the unit if external aerial are not used. You will need even more luck with the FAA to gain approval to have one (never mind the ideal two) external aerials bolted on the airframe. All in all I can think of all sorts of problems installing a Zaon in a certified aircraft and insurmountable problems if the aircraft were pressurised. Moreover I doubt even Zaon would claim this was the purpose for which the unit was disgned - you have to read a fair amount of tongue in cheek when they talk about how you might gain approval.

However, assuming for a moment you overcome all these problems, as pilot in command you then must consider what you do when an approved piece of equipment is not functioning. If you get 1 in 100 ghost alarms is it faulty? What about 1 in 50, or as you suggest 5 in 10 or more? At some point you placard the equipment as U/S and the shop either fixes it, the equipment is removed, or permanently maked u/s. You do that not only for yourself but for the poor sod who is next to fly the aircraft and entitled to think that everything not placarded or noted in the tec log is working,

For all of these reasons I think that anyone who panel mounts one of these units in anything other than a home built is attemting something that was never really intended and without at least one surface mounted external aerial is asking for all sorts of problems.

I reckon both units are designed to "sit" on the glare shield, where the aerial has the best chance of doing its job, wired into an accessory socket if you wish and correctly calibrated to the aircraft as recommened by Zaon.

In short if you gained a field mod including approval for at least one external surface mounted aerial I suspect your A&P had little idea what he was doing and if there were no external aerials included in the installation then he should be shot if only because you will be left with a rather redundant and ugly hole in the panel which would only be useful as a cig. packet holder - but fortunately they have been banned in the cockpit as well.

Sorry but the more I hear the less I am surprised that you encountered as many problems as you did which sort of comes back to my original point that if the issues arent understood dont be surprised if you dont like the results. One other lesson I have learnt is engineers get it wrong like the rest of us, just because they have a bit of paper doesnt mean they know what they are doing, so treat anything that doesnt appear to be working with a healthy degree of sceptism and dont assume that because it was "professionally" installed it is the equipment that is faulty and not the installation.

That's all you really need to know.

So you are at least right with one thing that is all I needed to know to make a pretty fair guess why you had so many problems.

That solved the thread has being going too long so I will leave it at that.

[SNS3Guppy]

Whilst we might not like it the theory behind what gets hard wired into the panel or doesnt is safety. Are the electronics sufficiently robust and resistant to short circuits and fire, do they represent a physical hazard in the cockpit or impinge on the pilot operating the controls or his view, and does the equipment do what is intended. I can see how you might mount the more basic version of the Xaon in the panel (and indeed Zaon even sell a kit) but I have no idea how you would panel mount the XRX given its shape.

The Xaon units were mounted on platforms which removed via a velcro interface. The electronics were wired as circuitry through the panel into a bus, protected by circuit breakers, and used as an approved installation. Because of the mount system, the units were considered removable and didn't require approval; because of the wiring, the installation was considered permanent, and did require approval. While the PCAS unit itself could be removed, the wiring could not, and therefore the entire installation required an approval. To my knowledge, no effort was sought to do this as an STC.

In these aircraft, nearly every aircraft system was modified, and the exterior of the aircraft had numerous other antennas, attachments, hardpoints, fuel tanks, and equipment above and below the aircraft, attached to wings, etc. Approvals existed, and are on file for all modifications in use in those aircraft.

However, assuming for a moment you overcome all these problems, as pilot in command you then must consider what you do when an approved piece of equipment is not functioning. If you get 1 in 100 ghost alarms is it faulty? What about 1 in 50, or as you suggest 5 in 10 or more? At some point you placard the equipment as U/S and the shop either fixes it, the equipment is removed, or permanently maked u/s. You do that not only for yourself but for the poor sod who is next to fly the aircraft and entitled to think that everything not placarded or noted in the tec log is working,

Not in that operation. Upon completion of a mission, squawks were noted, and the airplane became domain of the maintenance crew. End of story.

I reckon both units are designed to "sit" on the glare shield, where the aerial has the best chance of doing its job, wired into an accessory socket if you wish and correctly calibrated to the aircraft as recommened by Zaon.

Which is exactly the case here, save for the "accessory socket." Hard wiring was used for reasons concerning the wiring of the entire aircraft. Additional DC receptacles were available, but in use with other items. The PCAS, heads-up displays, and other field-expedient after-market items were hard wired as part of the installation package.

Sorry but the more I hear the less I am surprised that you encountered as many problems as you did which sort of comes back to my original point that if the issues arent understood dont be surprised if you dont like the results.

Nothing that was done occurred without understanding, without full compliance, and without consultation with the manufacturer. Those performing the installation were not backyard shade-tree mechanics, but avionics personnel with substantial experience.

Again, there is nothing about the operation of the Xaon units in those aircraft that would make them any less "reliable." The fact is that the Xaon unit is a cheap substitute for TCAS. That it costs a lot to the average private pilot doesn't change the fact that it's a drop in the bucket compared to a real TCAS. the Xaon PCAS is a gimmick which has some limited use, but may serve more to misdirect and put heads down in the cockpit than it does to actually locate traffic.

In the darkness it was better than nothing, it was in addition to other means available. My primary concern would be the private pilot that is somehow convinced by those foolish enough to believe the unit is reliable into using the PCAS to locate traffic...or worse yet, believing complacently that if the PCAS doesn't show traffic, it's not there.

Lest this sound far fetched, I see professional crews every day look for traffic with TCAS. I use TCAS heavily, but never in favor of old fashioned, Mark 1 eyeballs. Far too often I hear crews respond to a traffic report not with "traffic in sight," or "traffic not in sight," but instead with "Got 'em on TCAS." This doesn't help ATC, and doesn't really do much for spotting traffic. Most aircraft equipped with TCAS tend to spend much of their operational time at higher altitudes and in positive radar control, largely under IFR with a higher amount of instrument and head-down work.

In the private general aviation arena, conducted at lower altitudes, more frequently in the vicinity of an airport (with attendant higher traffic densities and distractions), by less experienced and lesser-trained pilots, may suffer even greater distractions or detriments from the use of additional gimmicks in the cockpit...especially units which don't provide substantial useful information, or which, like the Xaon unit, provide numerous false indications of traffic that doesn't exist. Aside from the private pilot having his attention drawn into the cockpit where it should be the least, sending the private pilot's attention on a wild goose chase for phantom traffic isn't conducive to a good scan, or to safety in general.

[chrisN]

My experience with PCAS is positive. I use it in a glider which has no transponder, and this may be the reason why I believe I have had no false positives or ghosts, certainly none of which I am aware.

(I have set out in other threads why I cannot fit a transponder, and do not propose to repeat it here.)

I have the simplest Zaon MRX device, which cannot give directional information; only range, relative height, and height trend of the nearest/most threatening contact.

I don't agree that it causes me to have more significantly more head down in the cockpit time. I do include looking at the unit in my normal instrument scan, which is insignificant in terms of total time, and the main thing I do when it gives an audible alert is to look out even harder than I already was.

In my last 40 hours/one year of flying, I have had one really serious alert which I was very glad to receive, relating to an aircraft coming up from below and behind to which I was completely blind visually.

I have had several other alerts which showed me just how bad my normal lookout is - and I can assure you I really do try, but my eyes, in common with almost all amateur pilots and a good proportion of professional pilots, are an imperfect device for acquiring 100% of other traffic.

Chris N