ADS-B Traffic Question

[kyleb]

Given that ADS-B is largely unavailable at low altitude, does it offer any benefit for the most likely place for traffic conflict - the airport environment, where most of the traffic is <2,000'?

Since the majority of midairs and close calls are in that environment, are we being oversold on the benefits of ADSB?

 

[N801BH]

Given that ADS-B is largely unavailable at low altitude, does it offer any benefit for the most likely place for traffic conflict - the airport environment, where most of the traffic is <2,000'?

Since the majority of midairs and close calls are in that environment, are we being oversold on the benefits of ADSB?

Bite your tongue........

The guv has NEVER forced a half baked idea down the publics throat..

 

[Velocity173]

Given that ADS-B is largely unavailable at low altitude, does it offer any benefit for the most likely place for traffic conflict - the airport environment, where most of the traffic is <2,000'?

Since the majority of midairs and close calls are in that environment, are we being oversold on the benefits of ADSB?

I didn't realize ADS-B was unavailable at low altitudes. I know TIS is because it's an ATC radar feed but isn't ADS-B going off of other aircraft in your area?

 

[Jay Honeck]

I didn't realize ADS-B was unavailable at low altitudes. I know TIS is because it's an ATC radar feed but isn't ADS-B going off of other aircraft in your area?

Yes. It works fine at low altitude.

 

[Piloto]

There is no coverage at pattern altitudes for many remote airports. This is why I opted for the Monroy Traffic-Watch and XM\WX. On several occassions it has alerted me on the ground of incoming landing traffic at the runway opposite end at TJMZ and other airfields with no ADS-B coverage. The voice warning and the traffic window pop-up on the G530 really calls your attention. ADS-B has some nice features if you are within coverage, like weather and ADS-B traffic. But I don't care about airline traffic at FL350 and I already have XM\WX that works on the ground and outside the US. I dropped my $85/month Direct TV subscription to pay for the $35/month XM\WX subscription.

José

 

[kyleb]

I didn't realize ADS-B was unavailable at low altitudes. I know TIS is because it's an ATC radar feed but isn't ADS-B going off of other aircraft in your area?

I dunno, which is why I axed... ;-)

 

[Jay Honeck]

There is no coverage at pattern altitudes for many remote airports. This is why I opted for the Monroy Traffic-Watch and XM\WX. On several occassions it has alerted me on the ground of incoming landing traffic at the runway opposite end at TJMZ and other airfields with no ADS-B coverage. The voice warning and the traffic window pop-up on the G530 really calls your attention. ADS-B has some nice features if you are within coverage, like weather and ADS-B traffic. But I don't care about airline traffic at FL350 and I already have XM\WX that works on the ground and outside the US. I dropped my $85/month Direct TV subscription to pay for the $35/month XM\WX subscription.

José

This is true while the system is being (ever so slowly) brought fully on line. In areas that ARE on-line (like San Antonio, where I flew yesterday) I could see (on my tablet, with ADS-B ) aircraft taxiing on the ground while I was in the pattern.

The picture is still incomplete, but getting better by the day.

 

[Bill Watson]

This is true while the system is being (ever so slowly) brought fully on line. In areas that ARE on-line (like San Antonio, where I flew yesterday) I could see (on my tablet, with ADS-B ) aircraft taxiing on the ground while I was in the pattern.

The picture is still incomplete, but getting better by the day.

That's been my experience. Most of the east has coverage though there is sometimes some 'strangeness' in the traffic support. Not sure if I'm seeing equipment or system strangemess but it's a pretty good package and clearly improving.

 

[midlifeflyer]

Personally, having flown in airplanes with TCAS I haven't seen much value of full capability in the traffic pattern. Unless you're going to be looking at the screen instead of outside, it seems to come down to a dialog that sounds like:

"TRAFFIC! TRAFFIC!"
"Yes, I know. Airport. Airport."

 

[gismo]

There is no coverage at pattern altitudes for many remote airports. This is why I opted for the Monroy Traffic-Watch and XM\WX. On several occassions it has alerted me on the ground of incoming landing traffic at the runway opposite end at TJMZ and other airfields with no ADS-B coverage. The voice warning and the traffic window pop-up on the G530 really calls your attention. ADS-B has some nice features if you are within coverage, like weather and ADS-B traffic. But I don't care about airline traffic at FL350 and I already have XM\WX that works on the ground and outside the US. I dropped my $85/month Direct TV subscription to pay for the $35/month XM\WX subscription.

José

This thread is a bit in error WRT the use of the term ADS-B. ADS-B is the direct transmission of one aircraft's position to other aircraft and is always available at any altitude provided the receiving aircraft is "listening" on the same frequency (1090 or 978 MHz). For aircraft monitoring both frequencies ADS-B "works" everywhere.

ADS-R is the ground based solution that allows an aircraft equipped for only one frequency to receive positions from aircraft on the other. This only works when both aircraft are within range of the ground station but when that network is completed I expect that there will be coverage in the traffic patterns of many if not most airports.

TIS-B is a connection between the ADS ground stations and the existing network of surveillance radars that broadcasts the position of non-ADS-B equipped aircraft detected by those radars to ADS-B equipped aircraft. Obviously for this function, the target aircraft must be high enough for their transponder to be picked up by a radar site but the receiving aircraft need only be in the service volume of the ADS ground station.

Bottom line: If you're equipped with ADS-B in on both frequencies you should see all ADS-B out traffic at any altitude. With single frequency ADS-B in you'll only see aircraft on the same frequency if you're out of range of a ground station. And non-participating aircraft are invisible to any ADS-B in equipment unless they are tracked by radar and you're in range of an ADS ground station. A passive (or better yet active) transponder detector does help fill in those two gaps.

 

[denverpilot]

Personally, having flown in airplanes with TCAS I haven't seen much value of full capability in the traffic pattern. Unless you're going to be looking at the screen instead of outside, it seems to come down to a dialog that sounds like:

"TRAFFIC! TRAFFIC!"
"Yes, I know. Airport. Airport."

ROFLMAO!

 

[gismo]

Personally, having flown in airplanes with TCAS I haven't seen much value of full capability in the traffic pattern. Unless you're going to be looking at the screen instead of outside, it seems to come down to a dialog that sounds like:

"TRAFFIC! TRAFFIC!"
"Yes, I know. Airport. Airport."

My active TAS calls "Traffic 12 o'clock same altitude" if I get in a situation where the closure rate suggests a noisy encounter in the next 60 seconds but it rarely gives an alert in the pattern other than for aircraft holding short of the runway when I'm on short final. I also find it useful as a second set of eyes for locating traffic in the pattern before I take off.

I do agree that passive traffic detectors are fairly useless in a busy pattern but even they can alert you to a nearby airplane you failed to see when the airport traffic is minimal.

 

[Velocity173]

Personally, having flown in airplanes with TCAS I haven't seen much value of full capability in the traffic pattern. Unless you're going to be looking at the screen instead of outside, it seems to come down to a dialog that sounds like:

"TRAFFIC! TRAFFIC!"
"Yes, I know. Airport. Airport."

I agree. It's kinda like TAWS in my aircraft when I'm flying through the mountains. "Terrain! Terrain! Pull up!" I know, I see the mountain.

Still these are good tools though. Few months ago the TIS alerted me to a T-39 on a MTR that was head to head with me. Without that traffic alert I'm not sure how soon I would have been able to see him.

 

[Bob Noel]

I agree. It's kinda like TAWS in my aircraft when I'm flying through the mountains. "Terrain! Terrain! Pull up!" I know, I see the mountain.

um, TAWS is supposed to do look-ahead in that if you continue on your current heading, you have less than 30 seconds (or some number of that I can't remember) before impact. TAWS isn't quite as panicky as TCAS.

btw - TAWS can't tell if you are IMC or VMC.

 

[Velocity173]

um, TAWS is supposed to do look-ahead in that if you continue on your current heading, you have less than 30 seconds (or some number of that I can't remember) before impact. TAWS isn't quite as panicky as TCAS.

btw - TAWS can't tell if you are IMC or VMC.

My point is, in a mountainous area TAWS is telling me what I already know (there are mountains around me). ADS-B in a traffic pattern is telling me what I already know (there's traffic in the pattern). Both situations are resolved by scanning for traffic / terrain and not flying with your head down.

Sure TAWS doesn't know if it's IMC or VMC. If you've gotten yourself into IMC and TAWS is yapping, you're in for a world of hurt. I prefer to use experience and good planning instead of relying on a TAWS to save my bacon.

 

[wabower]

Since the advent of $6-7/gal fuel prices at the big-city airports, traffic to outlying airports that offer savings of $2-3/gal has become common-place. Since the legs are short (30-50 nm), much of the traffic stays low, so the congestion is understandable. I got timely alerts from the Zaon for two such targets yesterday, as well as a few other alerts including a SWA 737 descending into OKC and a lot) of traffic in/out of ICT during a ~5 hour X/C of ~600 nm to the Twin Cessna convention. Got 3 phantoms as well, but they serve to keep me awake.

My active TAS calls "Traffic 12 o'clock same altitude" if I get in a situation where the closure rate suggests a noisy encounter in the next 60 seconds but it rarely gives an alert in the pattern other than for aircraft holding short of the runway when I'm on short final. I also find it useful as a second set of eyes for locating traffic in the pattern before I take off.

I do agree that passive traffic detectors are fairly useless in a busy pattern but even they can alert you to a nearby airplane you failed to see when the airport traffic is minimal.

 

[Bob Noel]

My point is, in a mountainous area TAWS is telling me what I already know (there are mountains around me). ADS-B in a traffic pattern is telling me what I already know (there's traffic in the pattern). Both situations are resolved by scanning for traffic / terrain and not flying with your head down.

Sure TAWS doesn't know if it's IMC or VMC. If you've gotten yourself into IMC and TAWS is yapping, you're in for a world of hurt. I prefer to use experience and good planning instead of relying on a TAWS to save my bacon.

And my point is that TAWS is telling you more that just that mountains are around you, TAWS is telling you to that if you do nothing you will likely hit something and end up having a very bad day.

one other thing: TAWS is not a substitute for experience and good planning. In reality, if pilots kept the airplane in protected airspace, then TAWS would be completely unnecessary.