ADS-B vs. "Active" Traffic ... Do you know the facts?
AUTOMATIC DEPENDENT SURVEILLANCE BROADCAST (ADS-B) OR ... "ACTIVE" TRAFFIC
There's a lot of talk about ADS-B but ... consider these arguments for adding Active Traffic NOW!
From Bob Hart Senior Avionics Consultant/ Marketing Manager APG Eastern Avionics
The 2020 mandate for ADS-B is about 8 years away, during which time there will be varying degrees of mixed equipage, but essentially everyone will still be required to carry a transponder. The fact is there are significant limitations with ADS-B that make having an active-surveillance system critical to flight safety both now and in the future.
Here are some of the considerations that make "Active" Traffic the right choice for anyone serious about Traffic Avoidance and Safety (and who isn't?):
1) Portable ADS-B units receive limited or no Traffic info. Some portable systems were designed to see other nearby aircraft that are sending an ADS-B Out signal, but currently there are simply not very many aircraft equipped for ADS-B Out. Since these portables do not send an ADS-B Out signal, the only way they can receive TIS-B traffic broadcasts from the ground is if they happen to be flying near an ADS-B Out equipped aircraft and they can eavesdrop on their signal. TAS interrogates and displays all nearby Transponder-equipped aircraft.
2) Limited Ground Station Coverage through 2014
While the East and West coasts have ADS-B-based ground stations in place, full US coverage is not expected until late 2014. Even with dual-band ADS-B products that may be coming out later this year, if you fly in areas without ADS-B ground infrastructure, you will not be able to see all the traffic. TAS does not rely on ground stations.
3) Limitations due to signal Line of Sight - At lower altitudes and especially in the pattern at many smaller G.A. airports, you may be below radar coverage and below ADS-B coverage, and thus not be able to receive ADS-R and TIS-B traffic. TAS works at any altitude.
4) ADS-B is dependent of GPS - An on-board GPS failure could cause you to lose your ADS-B and thus you would be without traffic awareness. During periods of poor satellite geometry or solar storms, ADS-B accuracy may be degraded or lost. TAS works independent of GPS.
5) 978MHz solutions do not work outside US. - It's important to keep in mind that if you fly to Canada or Bermuda or other regions of the world, the only ADS-B available is via 1090MHz and there are no mandates to equip for most aircraft flying below the flight levels. TAS works anywhere in the world.
There is great promise for ADS-B, but it has some limitations as a traffic detection safety system, especially during this critical mixed-equipage period.
The importance of having an active-surveillance Traffic Advisory System cannot be overstated. The key to safety with any traffic system is its ability to see and display all nearby aircraft.
Need more info about your "Active Traffic" options? Go to ...
http://www.apgavionics.com/product_info.php/tas-traffic-systems-p-638
This info courtesy of the nice folks at Avidyne Corporation
Wanna "Talk" about it? Contact Bob Hart APG Eastern Avionics (941) 637-8585 or rhart@avionix.com
There's a lot of talk about ADS-B but ... consider these arguments for adding Active Traffic NOW!
From Bob Hart Senior Avionics Consultant/ Marketing Manager APG Eastern Avionics
The 2020 mandate for ADS-B is about 8 years away, during which time there will be varying degrees of mixed equipage, but essentially everyone will still be required to carry a transponder. The fact is there are significant limitations with ADS-B that make having an active-surveillance system critical to flight safety both now and in the future.
Here are some of the considerations that make "Active" Traffic the right choice for anyone serious about Traffic Avoidance and Safety (and who isn't?):
1) Portable ADS-B units receive limited or no Traffic info. Some portable systems were designed to see other nearby aircraft that are sending an ADS-B Out signal, but currently there are simply not very many aircraft equipped for ADS-B Out. Since these portables do not send an ADS-B Out signal, the only way they can receive TIS-B traffic broadcasts from the ground is if they happen to be flying near an ADS-B Out equipped aircraft and they can eavesdrop on their signal. TAS interrogates and displays all nearby Transponder-equipped aircraft.
2) Limited Ground Station Coverage through 2014
While the East and West coasts have ADS-B-based ground stations in place, full US coverage is not expected until late 2014. Even with dual-band ADS-B products that may be coming out later this year, if you fly in areas without ADS-B ground infrastructure, you will not be able to see all the traffic. TAS does not rely on ground stations.
3) Limitations due to signal Line of Sight - At lower altitudes and especially in the pattern at many smaller G.A. airports, you may be below radar coverage and below ADS-B coverage, and thus not be able to receive ADS-R and TIS-B traffic. TAS works at any altitude.
4) ADS-B is dependent of GPS - An on-board GPS failure could cause you to lose your ADS-B and thus you would be without traffic awareness. During periods of poor satellite geometry or solar storms, ADS-B accuracy may be degraded or lost. TAS works independent of GPS.
5) 978MHz solutions do not work outside US. - It's important to keep in mind that if you fly to Canada or Bermuda or other regions of the world, the only ADS-B available is via 1090MHz and there are no mandates to equip for most aircraft flying below the flight levels. TAS works anywhere in the world.
There is great promise for ADS-B, but it has some limitations as a traffic detection safety system, especially during this critical mixed-equipage period.
The importance of having an active-surveillance Traffic Advisory System cannot be overstated. The key to safety with any traffic system is its ability to see and display all nearby aircraft.
Need more info about your "Active Traffic" options? Go to ...
http://www.apgavionics.com/product_info.php/tas-traffic-systems-p-638
This info courtesy of the nice folks at Avidyne Corporation
Wanna "Talk" about it? Contact Bob Hart APG Eastern Avionics (941) 637-8585 or rhart@avionix.com
Comments
A traffic picture taken five minutes ago does nothing for you when an aircraft comes up on you at 200 MPH. It's an entirely different discussion. I'm inclined to suggest that Active Traffic is the only way you can be sure you have the whole picture all the time and if you do purchase a Portable ADS-B or Zaon unit (they work pretty good also), you need to recognise that you now have some help but ... you don't have enough help to lower your guard and drop your vigilance. ADS-B, when fully imnplemented and with the full support of the GA fleet, will be great. The problem is between now and then. Speaking of now and then, I would not be in a hurry to buy into ADS-B out. The market is just starting to blossom and there will be lots of products and likely better pricing down the road (opps, I mean airway!) Thanks for commenting!
Bob Hart APG Eastern Avionics rhart@avionix.com www.avionix.com
No traffic solution should be considered perfect - if it is VFR, you are still responsible for seeing and avioding other aircraft. In IMC only, separation is the responsibility of the controller. Even if your flying on an IFR flight plan in VFR conditions, you are still responsible for seeing and avoiding other aircraft, no matter what technology is in the cockpit.
Bobs comment about XM or ADS-B weather is exactly right, but should be emphasized, they are to be used for weather avoidance only, not for trying to pick your way through a line of thunderstorms. XM/ADS-B or any other weather source except on-board radar can be delayed up to 15 minutes, and a cell can move a long way in 15 minutes!
However, it should not be inferred that because the ADS-B weather is delayed, that the same is true of traffic. Traffic is broadcast real time, and is not 5 minutes delayed. Weather requires the radar picture to be received and then composited from multiple radar sites, and then formatted and retransmitted to all the consumers. This is what causes the delay. Traffic is a 'local' function, and can be displayed in near real time. ADS-B 'out' aircraft are displayed based on the aircraft transmissions, not on the ground station anyway. The GDL39, and any other 'good' ADS-B receiver is responsible for filtering the duplicates from the rebroadcast information.
Mark
I was staying in a hotel directly below the final approach for the active runway at MIA - apparently about 500 feet below the glideslope! I was able to watch the airplanes fly overhead, and compare their position with what was shown on the screen - it was very accurate. As fun as that was, we didn't stay in THAT hotel the next night.....
Mark
Mark
Thanks, Tim
Seems I "sparked" a healthy discussion on the subject! Mark reminded everyone of the role of Nexrad Weather, that is, as a planning tool and not a a "defensive" tool in IFR conditions. You need real time weather information if you are going to "thread the needle" between two cells, for example. [/size] He specifically mentioned radar as that tool but my suggested tool for weather avoidance is a good, reliable, accurate stormscope. There are lots of reasons starting with budget. First of all, if you fly a single, in most cases, radar is not an option. Adding radar to twin is $ 22K using good quality used equipment like the RDR-2000. A good stormscope, like the L3 WX-500 (sensor for MFD's) or the WX-950 Stand along unit will be in the 6k to 8K range at most and, I think gives you exactly what you need to avoid Thunderstorm cells. I ask this question ... What are you trying to avoid? Hard rain? (no, not really an issue). Radar measures essentially, the intensity of precipitation. The assumption is then made that the areas where the heaviest rainfall is is where the cells are. Fact is, this is not always the case and if you have traveled around an area of heavy rain that is just that ... rain, you've wasted time and fuel. The "stormscope" measures lighting. It points directly to the cells. Why is this relevant? What we are in fact, trying to avoid is the intense turbulence and the risk of hail in the center of a cell. Surprisingly, the lightning strike itself is usually a minor issue but hail can take out out windshield and try to fly like that? The turbulence can be something else! I used to know the famous attorney F.Lee Bailey and I new his pilot. At the time (early 70's), Bailey had a Beech Duke. I talked to his pilot one day who told me that, thanks to ATC (that's an entirely other reason to have WX avoidance on board), they had ended up in the center of a cell a few days before. The Duke is a reasonably powerful aircraft. He said at one point, he was at full power and descending at 2000 FPM, the next minute, he was an idle power climbing at 2000 FPM.
He said they just held on tight and did there best to keep the aircraft level. Note Autopilots are useless in this situation and need to be shut off. My point is that a stormscope points you directly at the dangerous WX that you want to avoid and costs a whole lot less than radar. Also note, that ATC uses radar to help pilots avoid a dangerous WX situation and I have talked to more than one pilot who told me that sometimes, ATC doesn't get it right. Thanks for reading!
Bob Hart www.AvionixHelp.com
Bob's comments on the value of a Stormscope are good, although I personally think anyone trying to pick their way through a line of significant thunderstorms in a small aircraft is making very bad decisions. I've always figured if it is important for me to be there 'on time', then it is probably even more important for me to be there - which I won't if I'm lying dead in a field somewhere with aircraft parts strewn about me. I use all weather products for weather avoidance only, and I've never regretted it.
On ADS-B in generally, they just turned on the ground stations in our area a couple of months ago, and both the traffic and the weather work really well. I'm a 'participating' aircraft, and I start getting both traffic and weather info before I make the crosswind turn after takeoff. The traffic has made it clear to me that my eyes are not as good a tool for traffic as I thought. Just last week we had an airplane coming in to the pattern, never made a radio call, and from the looks of it, either didn't see the other plane already in the pattern, or didn't care. I was approaching the airport, and could see both aircraft on my iPad, but couldn't see them with my eyes until I was just about into the pattern. I made a call to the other plane (I knew the pilot) that was established in the pattern regarding the traffic, and he appreciated it a lot.
The non-communicative aircraft was doing a touch and go, and I had to delay my entry to give him space. If I hadn't seen him on the iPad, I wouldn't have seen him until I was already in the pattern, and we would have been much too close for my comfort.
Mark
As soon as I find out that the ADS-B works as well as XM WX, I will get rid of that subscription and let you guys/gals know.
Tim