Traffic alert system/TCAS

[Vegasflyer]

Hi,

I like any feedbacks for those who has them installed in their aircrafts. I had a close near miss last month as I was on short final. ATC cleared me to land and alerted another aircraft, a cessna 172 in the pattern that he was #2 to land behind me. The 172 turned base infront of me and scared the heck out of me so I am considering having TCAS installed. I was quoted 12k installed for the Avidyne system. Is this a reasonable quote and worthwhile investment.

Thanks for your inputs

 

[AirBaker]

TCAS is great as long as you don't forget to keep your head outta the cockpit. I've got the El Cheapo Mode S derivative and sometimes it scares me more than helps.

We use TCAS a lot on our large formation flights. Helps in the less maneuverable configurations.

 

[Ken Ibold]

You will have so many alerts in the traffic pattern you will either turn it off or learn to ignore it. There are lots of things that will give a better bang for the buck in terms of safety.

 

[sheldon957]

You will have so many alerts in the traffic pattern you will either turn it off or learn to ignore it.

I get this sometimes with plain TIS - Traffic Information System, which works off of ground radar and has a delay. When I turn upwind to cross etc.. I will often get a false signal which is me.

I am not sure if the TCAS is the same radar dependent, or directly interrogates the other transponder.

I don't see how a type that directly interrogates the other transponder could get a false signal.

Does anyone know for sure which of the many variants do that?

 

[Ken Ibold]

I am not sure if the TCAS is the same radar dependent, or directly interrogates the other transponder.

I don't see how a type that directly interrogates the other transponder could get a false signal.

Does anyone know for sure which of the many variants do that?

All real TCAS actively interrogates other aircraft. Most of the Ryan pseudo-TCAS also actively interrogate, although I think there are a couple older Ryan models that are passive.

I'm not just talking about false alarms, though. If you're approaching an airport there are going to be other airplanes. The box is stupid. It doesn't know whether the traffic has been called to you, so it's going to let you know. I fly a lot at busy airports, and if there are 3 in the pattern, 4 coming in, and one taking off, am I really going to pay attention to those alerts when I've got my eyes and ears on the situation already and have other chores to do?

My point is that midairs are so rare, that it makes no sense to spend $$$ on technology that does only marginally better than the tried and true eyes/controller combination. That investment in safety gear would be better put, IMO, into something like an EPIRB, a backup vac pump if you fly IFR in a single, on board weather, or something else that is more likely to be a threat to your well-being over the long term.

 

[mikea]

All real TCAS actively interrogates other aircraft. Most of the Ryan pseudo-TCAS also actively interrogate, although I think there are a couple older Ryan models that are passive.

I'm not just talking about false alarms, though. If you're approaching an airport there are going to be other airplanes. The box is stupid. It doesn't know whether the traffic has been called to you, so it's going to let you know. I fly a lot at busy airports, and if there are 3 in the pattern, 4 coming in, and one taking off, am I really going to pay attention to those alerts when I've got my eyes and ears on the situation already and have other chores to do?

My point is that midairs are so rare, that it makes no sense to spend $$$ on technology that does only marginally better than the tried and true eyes/controller combination. That investment in safety gear would be better put, IMO, into something like an EPIRB, a backup vac pump if you fly IFR in a single, on board weather, or something else that is more likely to be a threat to your well-being over the long term.

I think it'll help when you're outside of an airport pattern in nowhere/nobody land, but then that's not where most mid-airs happen.

I think your take on it is heavily influenced by weather you fly IFR all the time. For us in Chicago we can't get VFR flight following so as Bruce says he wants something. I think his TIS system is pretty good.

You can go with a portable like the Zaon to limit the expense vs. an installed system.

I flew with a buddy who had the Monroy stuck in his panel. We got an alert and sure enough spotted the guy at our altitude paralleling our course off the wing a few miles off.

 

[Areeda]

I have to agree with Ken, while I love traffic systems they are not very helpful in the pattern. It's much more effective to spend your time looking outside.

There are several systems out there. TIS uses information uploaded from approach radar via a Mode-S. There are several issues. As previously mentioned it may report your echo as a conflict on first hit. Also there are boundary issues. If you move from one radar service area to another you only get data from the one you're in. So as you approach the boundary you see nothing in front of you then as you pass you see nothing behind you. Next is the fact that the FAA is not comminsioning any more of these. As the current installations are upgraded (say 5-20 years) the upload sites will decrease. Price for a Garmin 330 is I believe about $4.500 + installation and needs something to display the data. Big advantage is that is gives you a projected path of each target as well as relative altitude and position.

TCAD, Skywatch and I believe other brand names are an active transponder based system. It will determine positions and relative altitudes of Mode C and Mode S transponders within its range (about 12 nm). these are in the $12-20,000 range.

TCAS is Collision and Avoidance systems. These are expensive because they negotiate an avoidance strategy with another equally equipped aircraft. One is told to climb, one descent, both are told to turn away from each other. I believe these are in the $50K range but I'm not sure.

For completeness lets also consider the the <$800 portable units. IMHO these work about as well as the X-ray glasses I bought from the back of comic books to see women's underware when I was in grade school. No Richard and Scott I did not buy them in the last month.

Joe

Oh shoot, If I'm going to complain about the cheap one I probably should have mentioned ADS-B, look it up and let me know please.

 

[ghogue]

TCAS is Collision and Avoidance systems. These are expensive because they negotiate an avoidance strategy with another equally equipped aircraft. One is told to climb, one descent, both are told to turn away from each other. I believe these are in the $50K range but I'm not sure.

Joe

Joe,

To my knowledge, there are no TCAS units that give directions to turn. Vertical commands only.

gary

 

[gismo]

You will have so many alerts in the traffic pattern you will either turn it off or learn to ignore it. There are lots of things that will give a better bang for the buck in terms of safety.

I've had a Ryan (Avidyne) TAS610 in my airplane for two years now and I think it works really well. So far I haven't had it save me from a potential collision but I haven't gotten a lot of false alarms either. It definitely helps me to locate traffic called by ATC (I normally fly IFR on trips) and I think it helps provide "another set of eyes" when departing or arriving at an uncontrolled airport (yes I know not all planes have transponders). And while I would agree that it's not going to help much at a real busy airport, even there I don't get a lot of false alarms (mine has an "approach mode" which tightens the criteria for an alarm).

One thing that's definitely important is complete verbal callout of serious threats. Mine vocalizes the "o'clock" position, range, and relative altitude but only on something it thinks needs immediate attention. Without the verbal announcements I'd have to look at the display when I should be looking outside to get any "benefit". I did have to train myself to look where it said the traffic was outside the plane rather than at the display screen which is where I instinctively wanted to look.

I've also used a couple portable passive devices and found that they were relatively useless, generally telling me that there were lots of planes around me somewhere when near an airport (something I already knew), generating multiple false alarms (ghosts that ATC couldn't see) and missing a lot of close traffic, especially from behind. One passive device I haven't tried is the Zaon ZRX which can display traffic on a portable GPS screen. Still I'd expect that it will be blind to a lot of traffic unless the unit is connected to external antennas and I'd also expect that the range indication is woefully inaccurate. The passive traffic detectors rely on signal strength for range vs signal transit time (like DME) for an active system like the TAS 600 series.

 

[nddons]

I've also used a couple portable passive devices and found that they were relatively useless, generally telling me that there were lots of planes around me somewhere when near an airport (something I already knew), generating multiple false alarms (ghosts that ATC couldn't see) and missing a lot of close traffic, especially from behind. One passive device I haven't tried is the Zaon ZRX which can display traffic on a portable GPS screen. Still I'd expect that it will be blind to a lot of traffic unless the unit is connected to external antennas and I'd also expect that the range indication is woefully inaccurate. The passive traffic detectors rely on signal strength for range vs signal transit time (like DME) for an active system like the TAS 600 series.

How do these passive systems compare to the traffic system on a G-1000-equiped C-172SP?

 

[gprellwitz]

How do these passive systems compare to the traffic system on a G-1000-equiped C-172SP?

I believe that's a standard mode-S TIS system, therefore dependent on approach radar and subject to the limitations previously discussed. I admit, though, that I cannot compare it point-by-point with other passive systems due to lack of direct experience.

 

[rottydaddy]

The dubious merits of TCAS in terminal areas aside...

An observation: you almost completely missed seeing another plane in a tower-controlled pattern. Chances are very good that they never even saw you.
This calls for a more vigilant scan and more robust mental picture of the immediate area based on radio chatter, not a gizmo to do that stuff for you.

Don't get me wrong: I've been there, and learned my lessons.
The most "where the hell did he come from?!" moment I ever had was in the pattern at a towered field. I was stunned to realize that sometimes cab controllers cannot see the whole pattern or are- gasp- assuming we are keeping our eyes peeled!!
The closest shave I ever had, however, was at an uncontrolled field, when I trusted a Bonanza pilot who called "3 miles out" and asked what runway was in use, then appeared right in front of me about a minute later as I was turning base, diving for the runway from above TPA with everything hanging out. He then called clear while he was rolling out...

Listen, but verify with your eyes... and if you don't see them, ask them where they are.

This episode was your lesson: whether it's Tower or Flight Following or TCAS, the more personal accountability you hand off to others who are not up there with you when flying VFR, the greater the potential for disaster due to even very slight complacency.
The vast majority of midairs occur on clear days near or in terminal environments, for the simple reason that there are more planes likely to be in a small area and pilots are thinking about or looking for something else or assuming that being controlled by ATC or saying "any traffic please advise" five miles out is going to cover their butts completely.

 

[sanchezpaulk]

Hi,

I like any feedbacks for those who has them installed in their aircrafts. I had a close near miss last month as I was on short final. ATC cleared me to land and alerted another aircraft, a cessna 172 in the pattern that he was #2 to land behind me. The 172 turned base infront of me and scared the heck out of me so I am considering having TCAS installed. I was quoted 12k installed for the Avidyne system. Is this a reasonable quote and worthwhile investment.

Thanks for your inputs

I'm fairly certain that was for the TAS600, not a TCAS.

You'll find that any traffic advisory system (TAS not TCAS) that creates its own radar environment (7 nm radius, ±3500' and up to 8 targets) is well worth the cost. Not having to depend on a controller noticing another target and then giving you notice. Plus your opportunity to determine the closest point of approach, where to look to visually acquire, and even to determine what action to take so the relative motion is no longer closing.

After it is installed do spend time on learning the software, techniques on evasive maneuvering to increase closest point of approach (distance and time).

 

[Joe B]

I was quoted 12k installed for the Avidyne system. Is this a reasonable quote and worthwhile investment.

Yes, that's a reasonable quote. Base price on the unit is $10k and the shop has to install antennae on both the top and bottom of the aircraft. Both the floor and the ceiling have to be opened up and put back together.

I've had a TAS600 for a couple of years and my comments echo Lance's. It's very handy to have an extra set of eyes, especially ones that are constantly watching your blind spots. That being said, I agree with Ken that this isn't necessarily the first piece of safety gear I'd install.

Regards,
Joe

 

[Teller1900]

Joe,

To my knowledge, there are no TCAS units that give directions to turn. Vertical commands only.

gary

TCAS III can give lateral commands, TCAS II is verticle only, and TCAS I simply tells you that there's traffic (TA=traffic advisory) but no resolution (RA=resolution advisory).

I've flown with the TIS that the newer Garmin 430 has...completely worthless, in my opinion. It got a ghost reply, usually from itself, more often than it gave worthwhile advice about other traffic. Steep turns and abrupt altitude changes (eg: stalls or turbulence) were enough for it to get a ghost reply from your own transponder.

The TCAS II we have in the 1900 is wonderful, on the other hand. Granted I'm not paying for it, so I can't say anything about how worthwhile it is as an investment, but I love it. Like Ken and a few others have said, it doesn't do a lot for you in the pattern, other than show you the general position of aircraft you may not have seen yet. Our's is tied to the radar altimeter so it will stop giving RAs below (I think) 2000 AGL; which is nice that it's not screaming at you when someone on the ground turns on their transponder as you're on short final. Overall, I love having it. It makes finding controller issued traffic a lot easier (in my opinion) and gives you a lot more information than most controllers do (such as whether or not you're closing on the target). And based on it's built in threat analysis, it gives you a lot more time to prepare and execute an escape maneuver if it becomes necessary. I personally love having it, but certainly wouldn't want to pay for it!

 

[flyingcheesehead]

I think it'll help when you're outside of an airport pattern in nowhere/nobody land, but then that's not where most mid-airs happen.

Maybe so, but...

One of the closer calls I've ever had was on the way to 6Y9 last year, up over northern WI where there's nothing but trees for miles around. A Cessna crossed our path from left to right, just a hair in front of us. I saw him late enough that had I been 1/2 second ahead of where I was, it would have required excessive maneuvering to avoid a collision.

 

[mikea]

Maybe so, but...

One of the closer calls I've ever had was on the way to 6Y9 last year, up over northern WI where there's nothing but trees for miles around. A Cessna crossed our path from left to right, just a hair in front of us. I saw him late enough that had I been 1/2 second ahead of where I was, it would have required excessive maneuvering to avoid a collision.

Yep. I've had a few of those, too, but I think every time it's been where what we might call the "extended approach path" to an airport. A LOT over the Fox Lakes where we're all ducking under the Chicago Bravo.

In cruise I once had IND ATC call out a Cessna coming off my left wing. I finally spotted him and watched him cross a couple hundred feet directly below me. I think he was departing an airport to my left.

 

[AirBaker]

I've flown with the TIS that the newer Garmin 430 has...completely worthless, in my opinion. It got a ghost reply, usually from itself, more often than it gave worthwhile advice about other traffic. Steep turns and abrupt altitude changes (eg: stalls or turbulence) were enough for it to get a ghost reply from your own transponder.

The only times I get a false positive on the TIS system (430W + 330) is when I'm just entering the TIS coverage area. Otherwise the system is as accurate as radar is.

 

[Teller1900]

The only times I get a false positive on the TIS system (430W + 330) is when I'm just entering the TIS coverage area. Otherwise the system is as accurate as radar is.

I don't know, maybe ours was an early model, but the TIS just annoyed me. It also seemed to SCREAM "Traffic unavailable" at random, and seemingly inopportune moments (often on short final).

 

[sanchezpaulk]

I don't know, maybe ours was an early model, but the TIS just annoyed me. It also seemed to SCREAM "Traffic unavailable" at random, and seemingly inopportune moments (often on short final).

And what was your height above ground as compared to the distance to the ASR7, ASR8, ASR9 radar site when you were on "short final"?

 

[Teller1900]

And what was your height above ground as compared to the distance to the ASR7, ASR8, ASR9 radar site when you were on "short final"?

Beats me. For one I don't know where the nearest ASR7/8/0 site is to KIWA, and also; I didn't pay that much attention at the time. I just know it happened a few times in cruise startling the hell out of me, and a few times on final, startling the hell out of me. Did it in the middle of my instrument checkride, too, while I was holding out at Casa Grande - startled the hell out of the DE. We only had a couple planes with TIS, the rest just had straight 430s with no traffic, and none of them had WAAS. I'm not trying to offer technical advice, in reference to the OP, just saying that in my personal experience, TIS was a lot more annoying to me than TCAS II has proved to be.

 

[SCCutler]

I have flown extensively in Mode S TIS-equipped aircraft, and think it is very useful; but for the announced abandonment of the technology by the FAA, I'd be all over it. Mt plane's transponder is a recent GTX327, so it's not likely I'll be getting a 330, but if I needed a transponder now, I'd surely consider it.

 

[AirBaker]

I have flown extensively in Mode S TIS-equipped aircraft, and think it is very useful; but for the announced abandonment of the technology by the FAA, I'd be all over it. Mt plane's transponder is a recent GTX327, so it's not likely I'll be getting a 330, but if I needed a transponder now, I'd surely consider it.

Rumor was that there'd be an ADS-B update for the 330, but otherwise I'd just put in a 327 if I was doing it over again. There are just too few areas that have the service IMO.

 

[OtisAir]

I have a Monroy I don't use very often. Still trying to decide if I sell it, trade it, or keep it for occaisional use. I've heard of a few small FBO's using a Monroy in their shops to be alerted of aircraft flying in.

 

[gismo]

You will have so many alerts in the traffic pattern you will either turn it off or learn to ignore it. There are lots of things that will give a better bang for the buck in terms of safety.

I've had the Ryan/Avidyne TAS610 for a few years and I really like it. I'm based at a busy, towered reliever for MSP yet I rarely get an alert near the airport. But the two best things about this system are the verbal callout of traffic including relative altitude plus clock position and the fact that it works at rural airports, even when I'm on the ground (as long as the other aircraft have operating transponders). I will say that I'm only able to visually acquire about 20% of the traffic that shows up on the display but are not considered worthy of "alert status".

 

[John Collins]

Rumor was that there'd be an ADS-B update for the 330, but otherwise I'd just put in a 327 if I was doing it over again. There are just too few areas that have the service IMO.

The GTX330 now has ADS-B out capability, so you can tell others where you are, but can't display where they are. Not much interest for me as I want ADS-B In capability where I can display where other traffic are located. If you already have a GTX330 installed, it can be upgraded, I think for $1000 or so, but why would you do it? Also, if the current rule proposed by the FAA for ADS-B stands, the GTX330 would have to have dual antennas and this is only available on the GTX330D which is twice the GTX330 price.

 

[CT Arrow]

If you already have a GTX330 installed, it can be upgraded, I think for $1000 or so, but why would you do it?

Aburd isn't it? It makes no sense....

 

[Joe B]

If you already have a GTX330 installed, it can be upgraded, I think for $1000 or so, but why would you do it?

I will probably take this upgrade path when the FAA makes ADS-B Out mandatory. My aircraft is already equipped with Ryan's TCAD and an XM receiver, both of which work just fine whether or not I'm within line-of-site range of an FAA ground station. I have no desire to downgrade to ADS-B In.