"Cheap" traffic options?

Ted

Ted

The pilot formerly known as Twin Engine Ted
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iFlyNothing
I realize this is an oxy-moron.

My goal for this year is to get the 310's avionics to have a fully appropriate setup for the kind of flying we do with it. To that end, we're planning on acquiring and installing a real radar unit, likely a stormscope. I'm also interested in adding traffic of some sort to the plane.

The obvious easy way to do this is with a GTX330 transponder (we may end up needing to change the transponder anyway, in which case that'd be a simple solution). However, that only gives me TIS. While that will give me traffic in the areas where I arguably need it the most, it's still a partial solution.

Given the fact I do a decent amount of flying in uncontrolled airspace, it would be nice to have some sort of real traffic that can give me an idea if there is actually someone else in these clouds I'm flying in above wilderness nowhere in Canada.

From what I can tell, the "cheapest" solution is the Ryan/Avidyne 9900BX, which is "only" about $20,000. The various 8800/9900 lower end TCAD stuff Ryan puts out is interesting. However, the fact that it requires the transponder to be getting pinged by another source in an area where there's no other source to be pinging it (hence why they call it TCAD and not TCAS), only seems marginally more useful than TIS. To that end, I might as well just get the 330 installed and leave it at that.

Of course, in those areas things are uncontrolled because there's so little traffic anyway. Admittedly, the big sky theory works well out there, and the majority of incidents are CFIT caused by people either skud running or having some other screwup, especially at night. But I'm wondering if there are some more affordable options out there that could be considered, either installed or portable. The portable units I've seen I've not been very impressed with, but there may be new ones out there that I haven't seen.

Any thoughts or suggestions appreciated.
 
The only StormScope I know is a 'spherics device that displays electrical energy -- it's not a radar.

This plus XM is provides all the info one needs to see and avoid CB.

The TCAS-type devices are only going to show you Transponder-equipped aircraft, not non-electrics and folks who refuse to turn them on. Given you fly mostly IFR I'd think you already have more traffic avoidance than an additional $20k will provide...

:dunno:
 
dmccormack said:
The only StormScope I know is a 'spherics device that displays electrical energy -- it's not a radar.
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Correct. I'm planning on both.

This plus XM is provides all the info one needs to see and avoid CB.
Click to expand...

I'd disagree with that. Fly with real radar for a while and it becomes quite clear that XM is a poor substitute. What XM is useful for, however, is getting weather at your destination while still a ways out, and seeing just how far this line really does go, or making plans a couple hundred NM past your radar's useful range for avoiding the whole system entirely.

The TCAS-type devices are only going to show you Transponder-equipped aircraft, not non-electrics and folks who refuse to turn them on. Given you fly mostly IFR I'd think you already have more traffic avoidance than an additional $20k will provide...

:dunno:
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There are a few points to make here:

1) When I'm flying IFR in uncontrolled airspace in Canada, I'm not talking to anybody, and neither is anyone else. That's the principle use of a system like this.

2) Flying IFR means you have required separation from IFR aircraft, not VFR. Even then, controllers mess up, and I do fly VFR in areas where IFR doesn't make sense to given the performance of my aircraft. Last year somewhere around Peoria (while IFR), a Grumman was coming straight for me, right at my altitude, at my 9 o'clock (VFR). By the time ATC noticed and said anything to me, I had very little reaction time. He saw me about the time I saw him, and he broke off behind me and climbing as I descended. Obviously, it all worked out. Had I my own equipment, I'd know where to look.

Now, a few years ago when the Cessna 140 flying 100 ft below me, head on, was coming right for me and I didn't see him until he was right under my left engine nacelle wouldn't have been helped - he didn't have his transponder on (if he had one at all). I asked ATC if he had anything around me afterwards, got a negative.

As I said, this is a nice-to-have. I used to not be a believer in the nice-to-have gadgets. However, I suppose I'm getting old now, and realizing more and more that I am just as susceptible of becoming an NTSB report as anyone else. As such, I'll take all the help I can get to avoid that from happening.
 
Keep an eye out for ADS-B receivers that will get the ADS-Rebroadcast from the ground stations. As the roll-out continues you'll find more and more coverage. You could use a tablet or a smartphone as a display unit, though there are some MFDs (Garmin MX20-type unit) that may be able to display both radar and ADS-B traffic info.
 
Again, that is only helpful when ADS-B is around. If I want that, I can go for a GTX330.
 
Well if you want something autonomous that you can rely on, then you're looking at an active interrogating system like the one you mentioned for 20 AMUs, and the prices go up from there.
 
Hence the point of my question, are there other options I haven't listed that are worth consideration and might be cheaper. :)
 
A marine broadband radar like this model could provide warning of transponderless airplanes (or when outside radar service areas) and terrain obstructions out to 30 nm (and even birds) at a "reasonable" cost (the video on that page provides some graphic demos):

http://www.lowrance.com/Products/Marine/Broadband-Radar/Broadband-4G-Radar/

Just one problem: The FCC license would prohibit use in anything other than a boat.

(They claim elsewhere that multiple radar units can operate near each other with no interference.)
 
Ted, just train one of the mutts you fly to be a seeing eyedog. If they can help seeing imparied folks avoid objects it might work for you. Granted, Radar won't poop on the floor but all in all the dog will likely be more reliable and won't develop electrical gremlins and really would be pefect for your operation, ya know flying dogs and all.
 
Ted DuPuis said:
Again, that is only helpful when ADS-B is around. If I want that, I can go for a GTX330.
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Two separate things, Ted, with two separate capabilities.

The GTX330 only works where the ground radar is transmitting TIS back out. Most larger TRACONs do that, but a very wide swath do not. It's not really an issue on the east coast (VA/NC line northward), but it is in more rural areas. when I used to fly between SSF and the East Coast regularly, I'd estimate that there was TIS coverage on the 330 for 25-ish percent of the tirp. And that was at 10,000 and above.

ADS-B only works in it's coverage area, and is not tied to radar coverage areas. I don't have ADS-B, but my understanding from folks that do is that it currently offers coverage in some more rural areas. Of course, it requires different equipment. The GTX-330ES meets the FAA specs for ES transmission to participate in ADS-B, but does NOT receive the ADS-B uplink.... that requires another box and compatible display. About the most affordable ADS-B package is the NavWorx box(es).

Neither of those work with non-electic aircraft. ADSB where the other aircraft is outside of radar range only works if the other airplane has ADSB-out. Otherwise, as you note, neither work.

The only real solution, then, is to have an active interrogator on your plane and hope that the other aircraft has a transponder (and it's turned on). As you note, that costs $$$$. And it doesn't work if other aircraft has no transponder.

Ted DuPuis said:
Hence the point of my question, are there other options I haven't listed that are worth consideration and might be cheaper. :)
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If I didn't already have the -330 (and I were flying more), I'd probably put in ADS-B now with a NavWorx box. Even with the -330, I'd consider something like the NavWorx box.... Garmin is just too pricy.

For what you're looking for, the "best" solution is to go active transponder interrogator - at the 20 AMU pop.
 
AdamZ said:
Ted, just train one of the mutts you fly to be a seeing eyedog. If they can help seeing imparied folks avoid objects it might work for you. Granted, Radar won't poop on the floor but all in all the dog will likely be more reliable and won't develop electrical gremlins and really would be pefect for your operation, ya know flying dogs and all.
Click to expand...

I think you need to train a traffic spotting hawk, not a dog. And get an owl for flying at night.
 
Ted DuPuis said:
I'd disagree with that. Fly with real radar for a while and it becomes quite clear that XM is a poor substitute. What XM is useful for, however, is getting weather at your destination while still a ways out, and seeing just how far this line really does go, or making plans a couple hundred NM past your radar's useful range for avoiding the whole system entirely.
Click to expand...

I used the StormScope to confirm or adjust what XM was displaying. Rarely was there a significant difference, and if there was, it was one of those weird days when it's CAVU but XM is showing light green over half the world.

On board radar has its limits, and I prefer XM's overall mosaic view (despite the time lag). But that's just me. I would NOT trust XM alone -- that's why the 'spherics device is so essential -- it can help spot and avoid those embedded CB we are plagued with 5 months out of the year.
 
One low cost traffic device that has worked very well for me in the Bahamas and the US is the Monroy Traffic-Watch http://www.monroyaero.com/ATD300Webpage8.pdf

Unlike ADS-B there is no need for ground infrastucture. It receives the traffic transponder signal directly. About $1000 and easy to install. Highly recommend it.

José
 
Ted, I will give you my $.02 worth. On the Radar. I agree if you only have one device then airborne radar is the way to go. I would absolutely insist on a phased array (flat plate) antenna of the largest diameter you can fit in there. The shape of the beam is critical to performance. Years ago I flew with a RDR 160 with a 10 inch parabolic. 40 miles was the absolute limit it could be trusted at. Also the parabolics are more prone to side lobe interference making the shorter ranges harder to use. Once you got into rain the range was cut to no more than 30 miles. The radar I use now has an 11 inch phased array and is solid out to 80 miles.
If you have XM already then you should have lightning detection with that. As you pointed out I do not use XM for picking my way through a line but it is good for deciding what part of a line to pick your way through. One of the most valuable uses IMO is to make sure your on board radar is not shadowing or being intinuated (sp?). Another discussion for another thread. I do like XM and consider it essential now.
On the traffic avoidance. I am not sure about all of the abbreviations but before this plane I had the system that depended on the transponder in the traffic to be pinged by ground based radar. For the most part is was useless for me. My biggest need was down low around uncontrolled airports. When you got that low you were below radar coverage and it was no good. Also it would not show aircraft lifting off for the same reason. I now have what I refer to as TCAS. It interogates the traffic transponder directly. Works well most of the time. You do need the dual antenna or you get a lot of blind spots. I don't have the same problem as you since almost all of my enroute is in radar coverage. However in busy areas the TCAS can become almost useless since it is hard to figure out what to do with multiple targets. Mine only shows how far above or below the target is, distance, and direction. It does not show the direction of flight. It does show if the target is climbing of descending. Frankly it is the one device I could do with out, but it is nice. And yes it is quite expensive.
 
wsuffa said:
Two separate things, Ted, with two separate capabilities.

*snip*
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Thanks for the education - I'd thought that TIS and ADS-B traffic were the same. So an ADS-B box would probably be more useful than a TIS box, but both of them have limitations that I'm trying to avoid.

The various passive traffic systems that work using the responses pinged to transponders by other sources (ground or aircraft with true TCAS) are, to me, one step above. But of course if you have two piston jobs bombing around in the clouds, neither with TCAS, neither getting pinged, both with Mode-C on and squawking 1200, it wouldn't help.

Neither of those work with non-electic aircraft. ADSB where the other aircraft is outside of radar range only works if the other airplane has ADSB-out. Otherwise, as you note, neither work.
Click to expand...

Correct. All systems have their limitations and at some point fate just decides it doesn't like you.

For what you're looking for, the "best" solution is to go active transponder interrogator - at the 20 AMU pop.
Click to expand...

That's what I'd figured, but was hoping that might not be the case. Hence the purpose of this thread. :)

dmccormack said:
I used the StormScope to confirm or adjust what XM was displaying. Rarely was there a significant difference, and if there was, it was one of those weird days when it's CAVU but XM is showing light green over half the world.

On board radar has its limits, and I prefer XM's overall mosaic view (despite the time lag). But that's just me. I would NOT trust XM alone -- that's why the 'spherics device is so essential -- it can help spot and avoid those embedded CB we are plagued with 5 months out of the year.
Click to expand...

You are correct in not trusting XM alone. However, the reason I prefer both StormScope and on-board radar is because the radar picks out a lot of things that the StormScope doesn't (remember, there are storms without lightning that you would want to avoid) and vice versa. Working with just radar has always worked for me.

XM has its uses (primarily with various strategic planning further out), but it is not on-board radar. Furthermore, a lot of the areas that I fly in (the same ones where I'm the most interested in having some sort of traffic) are areas that aren't served by XM.

ronnieh said:
Ted, I will give you my $.02 worth. On the Radar. I agree if you only have one device then airborne radar is the way to go. I would absolutely insist on a phased array (flat plate) antenna of the largest diameter you can fit in there. The shape of the beam is critical to performance. Years ago I flew with a RDR 160 with a 10 inch parabolic. 40 miles was the absolute limit it could be trusted at. Also the parabolics are more prone to side lobe interference making the shorter ranges harder to use. Once you got into rain the range was cut to no more than 30 miles. The radar I use now has an 11 inch phased array and is solid out to 80 miles.
Click to expand...

Definitely agree on the best I can get in. I think the unit in there before was an RDR-160. I've liked those, also had good luck with the KWX-56. But that's another discussion.

If you have XM already then you should have lightning detection with that.
Click to expand...

I don't have XM anymore, but that's also still ground-based lightning detection with a delay, just like other XM weather.

Frankly it is the one device I could do with out, but it is nice. And yes it is quite expensive.
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That's why it's at the bottom of the nice-to-haves list. We're expecting to do a trip to the avionics shop to get real radar installed as well as a stormscope (probably) at some point this winter. I will likely get my download weather going again. I've been flying some aircraft with various forms of traffic and been appreciating the info it provides.
 
Well, one thing to think about. You might look for a display unit that'll work with your radar AND be an ADS-B compatible display for when you upgrade.

What I heard at AOPA last year was the FAA was considering subsidizing design of a base black box that would be the core of an ADS-B unit with 1090 and 978 input and output, and the specs/software would be public, meaning that Garmin or Honeywell could go right to manufacture without a lot of individual design work and certification and just wrap additional features in their surrounding units that interface, like the MX-20. So it's possible that things may be faster and cheaper than previously thought. However, the Gov't is famous for snatching defeat from the jaws of victory (like the are doing with new Cloud security rules), so we'll see.
 
So they can afford to subsidize engineering development of this box, but can't afford to pay for webserver bandwidth to distribute charts?

That might indicate that someone has their head up and locked, as it relates to overall priorities...

But I'd never think that. ;)
 
denverpilot said:
So they can afford to subsidize engineering development of this box, but can't afford to pay for webserver bandwidth to distribute charts?

That might indicate that someone has their head up and locked, as it relates to overall priorities...

But I'd never think that. ;)
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Different pots of money.
 
I have a Mooney so onboard wx radar is out of the question. But found the XM/WX satellite image to be very useful in absence of precipitation. It gives you an idea for the shortest path to cross bumpy cloud cover that radar or stormscope would not show. Found it to be pretty accurate even though the image update is about every 5 minutes. Another useful XM/WX data is the cloud tops. This gives you an idea of the visibility and turbulence activity within the cloud cover, very useful. Over the Bahamas all that I get is the satellite image that still very useful.

José
 
denverpilot said:
So they can afford to subsidize engineering development of this box, but can't afford to pay for webserver bandwidth to distribute charts?

That might indicate that someone has their head up and locked, as it relates to overall priorities...

But I'd never think that. ;)
Click to expand...

Read about the FAA's AAS program some time. Search on FAA AAS in your favorite search engine.

Then answer the rhetorical in your second paragraph.
 
Ted:

I think the passive systems are better than some give them credit for. Very rare, indeed, are the times I have flown without something interrogating the xpdr. Remember, as long as you are in receive-range of any airliner, bizjet or other TCAS-equipped plane, or other interrogating device, so will the traffic you hope to avoid, and their transponder will respond. And there's your target for your relatively-inexpensive passive device.

I really cannot recall the last time I was flying and did not see a regular "R" pop up on the transponder.
 
For weather detection consider an airframe that can put you up into flight level 400+ - weather? We ain't got no stinking weather up here...

OK, levity aside -
For anticollision out in the boonies consider spending a few AMU on some really BIG strobes and an alternator to run them when you are not in the soup... Given that being hit from behind is not a big threat, then focusing the light energy forward is good... How about HID wing lights on a wig-wag pulser?
A Strikefinder of some sort is the least expensive means of seeing significant convective activity...
XM is probably nice for seeing fronts, but a call to FSS works for me... And a smartphone today can display all the weather you need... Out in the boonies of Canada probably XM is your best choice - though the information gets thinner the further north you go...

I had color radar in an Aztec... It was a fun gadget, but that is all it was... It did show areas that had precip... I never found it to be useful as an anticollison device...
For collison duty the Monroy, etc. units cannot hurt... However the unbiased articles I read do not think a whole lot of them... Still something is better than nothing...

In the outback of somewhere, probably the big sky and flying high is your best friend...
Where possible, simply filing IFR is your best protection...

denny-o
ahh, if I were only young again - and dumb...
 
The real short answer to your question is, 'it doesn't exist yet'.
 
Piloto said:
I have a Mooney so onboard wx radar is out of the question. But found the XM/WX satellite image to be very useful in absence of precipitation. It gives you an idea for the shortest path to cross bumpy cloud cover that radar or stormscope would not show. Found it to be pretty accurate even though the image update is about every 5 minutes.
Click to expand...

Try flying through some more rapidly-changing or developing storms. You might feel differently afterwards.
 
SCCutler said:
Ted:

I think the passive systems are better than some give them credit for. Very rare, indeed, are the times I have flown without something interrogating the xpdr. Remember, as long as you are in receive-range of any airliner, bizjet or other TCAS-equipped plane, or other interrogating device, so will the traffic you hope to avoid, and their transponder will respond. And there's your target for your relatively-inexpensive passive device.

I really cannot recall the last time I was flying and did not see a regular "R" pop up on the transponder.
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BTW ADS-B 1090MHz transponders do not need an interrogation to transmit traffic data. By design they periodically (1 per second) transmit traffic data. This way passive system can detect ADS-B equipped traffic without any interrogations to it.

José
 
Piloto said:
One low cost traffic device that has worked very well for me in the Bahamas and the US is the Monroy Traffic-Watch http://www.monroyaero.com/ATD300Webpage8.pdf

Unlike ADS-B there is no need for ground infrastucture. It receives the traffic transponder signal directly. About $1000 and easy to install. Highly recommend it.
Click to expand...

I thought this thing was pretty darn cool, and have shown it around to some new pilot friends. Anyone use one?
 
Piloto said:
BTW ADS-B 1090MHz transponders do not need an interrogation to transmit traffic data. By design they periodically (1 per second) transmit traffic data. This way passive system can detect ADS-B equipped traffic without any interrogations to it.
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I'm going to assume that they also have a "back off" timer that slows those transmissions or that's one seriously screwed up data system design. Just by the math, it has a built in limit of 60 nodes in range of the receiver before collisions start if every participating node can hear all others and no node's random number generators hit the same timeslot for transmission.

With some of those nodes likely to not reach the central receive antenna (the "hidden node syndrome") somewhere around 45 aircraft would bog the network down with say, 5 hidden nodes, from experience and a guess at the numbers. There's some formulas for hidden node collision rate probability out there, but roughly 80% of designed maximum packet rate works for systems that have no other anti-colision mechanisms.

"Doubling"...or one transmission happening over the top of another also happens in real world mobile data networks and it really gets bad when antennas are blocked by objects if there's full buffers and data retransmission to catch up on. It causes cascading failures.

In the case of the ADS-B data, there's nothing to buffer that requires an ACK that I can think of, so the math and effects are more straightforward than a stateful datagram system.

I'd have to see the design doc, but there's no way a modern data engineer designed it with a hard coded 1 per second rate. Or they're a complete idiot and every engineer who reviewed that timeline chart or drew one from their text description, is too. Or... They're not expecting more than 60 maximum targets will be in range of a single receive antenna.

1 per second might be the "best effort" rate under ideal conditions, but it's not the whole story and certainly the ground receiver won't receive every one of those transmissions if that really is the design.
 
"Doubling"...or one transmission happening over the top of another also happens in real world mobile data networks and it really gets bad when antennas are blocked by objects if there's full buffers and data retransmission to catch up on. It causes cascading failures.

Keep in mind that the ADS-B messages are relatively of short duration (less than 200usec) so you can accomodate 5,000 transmissions in one second without a high degree of garbling. In fact the garbling effect is more pronounced in the current Mode C surveillance scheme were multiple transponders reply to the same interrogation.

José
 
200 uSec? Wait... How much data is in the frame including framing/sync bits? That sounds screamingly fast for something in a narrowband 900 MHz channel.
 
denverpilot said:
200 uSec? Wait... How much data is in the frame including framing/sync bits? That sounds screamingly fast for something in a narrowband 900 MHz channel.
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ADS-B data is sent on the Mode S format at 1Mbit/sec on 1090MHz. This is a wideband data stream, thus unlike internet links it requires the relative high power (200 to 600 watts) that transponders put out. More info at http://rfdesign.com/military_defense_electronics/radio_understanding_mode_technology/


José
 
TMetzinger said:
And what does it do on 978?
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I think UAT on 978MHz is going face the same faith as LORAN. Unlike LORAN or GPS UAT only benefits the aviation sector. And the UAT benefits are already provided by XM\WX and TCAS with a greater more efficient coverage. XM\WX provides weather information to the maritime sector which is over ten times bigger than the aviation sector. There are ongoing studies and tests to broadcast WX data on the WAAS and other geo sync. satellites on the GPS band. This would provide WX data for the oceanic areas besides North America. It will also eliminate the need for a separate receiver/antenna since the same GPS receiver could receive the WX data thus lowering the unit cost. This will make possible that all GPS sectors (maritime, aviation, land & military) have WX and other related information in a more compact lower cost unit.

José
 
See, we're hearing here that the transponder-based system will be too overloaded and to expect to have to install the 900 MHz box for any of the features anyone would actually be willing to spend the money to get ADS-B for.

Until they actually do some real engineering and then the hard work of selling the system as a whole to folks, most of us are more than willing to be either in a wait-and-see mode, or outright contempt for the lack of planning.
 
The 1090 will be ok for the "here I am" messages (and listening for them), but that's all.

You want a real data link for weather/clearance/in-flight advisory/increasing capacity at non-towered fields/etc, you need 978.
 
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