How do I know if my Txpdr is ES

Can anyone post a summary of equipment that either currently or imminently offers TAS functionality, using ADS-B?

Here in the US, ADS-B is dual frequency one based on the Mode S transponder 1090ES (1090 MHz) and the other based on UAT (978 MHz). UAT may be used below 18000 MSL, above that level 1090ES is required. The mandate begins in 2020. The two frequencies don’t directly talk to one another. The defacto standard for GA using ADS-B In is a dual frequency receiver, so they can see targets based on either frequency. ADS-B has a low penetration in the US, but it is growing. The UAT provides the same traffic capability as the 1090ES, but offers GA another carrot, free weather in the cockpit. I installed a GDL88 that is based on UAT for ADS-B Out and has a built in dual frequency ADS-B In receiver. It displays traffic and weather on my GNS530W.

The primary purpose of ADS-B is improved surveillance for ATC. Traffic display is a byproduct as is the free weather. Because ADS-B is not required everywhere, there will be many aircraft that will never be updated. One can fly coast to coast and stay below 10,000 MSL (2500 AGL in the mountains), clear of Class C and B airspace and not need to comply with the mandate.

Ground stations called Ground Based Transceivers (GBT) are integral to the system’s operation. They receive the ADS-B position reports and pass them on to ATC. There isn’t a need for the GBT to be sending anything to the aircraft, but in the US they do send information that can benefit aircraft. If one doesn’t have an active TAS or TCAS system, one does not get a complete picture of the traffic, particularly any aircraft target that is not ADS-B equipped. Today, this is probably 5% of the traffic that comply. In the future after 2020, compliance will be much improved, but never get to 100%, maybe in the 80 to 90% range. So one of the services of the US GBT is to transmit TISB target data that is based on aircraft with mode C/S transponders but otherwise are not compliant with ADS-B. For a target to be visible in my cockpit, it either has to be ADS-B Out equipped in which case I receive it via air to air or a TISB target in which case, I must be within line of sight reception range of the GBT and a ground radar has to detect the target. Enroute, this is as good as TAS, but in the pattern, below radar coverage or below line of sight to the GBT, I can’t see the TISB traffic and a TAS is superior. At my airport, there is a GBT on the field within 200 meters of my hangar and radar coverage is available at about 400 AGL, so I see traffic in the pattern, but they drop out on final approach.

Note, the airlines have no interest in TISB or weather in the cockpit as they have on board radar and TCAS. If the EU is airline oriented, these types of services are not needed and makes ADS-B In much less desirable for the GA pilot. Here in the US, the infrastructure of some 800 GBT locations is largely installed and GA gets more benefit from the system than the airlines. Airlines have not yet seen a financial case for ADS-B In.

Thanks for a great explanation, NC Yankee.

My question would be based on the assumption that the European powers to be will not do anything for GA i.e. no weather or traffic will be radiated by ground stations. That is how Mode S was implemented.

So a GNS/GTN box, with a separate 1090ES ADS-B receiver, can provide traffic info by itself?

Presumably, Avidyne’s claim of ADS-B capability (one day) is that a similar 1090ES receiver could be connected to the TAS605 and then the ADS-B derived traffic could be displayed on whatever the existing display device is?

Achim,

That is standard Mode S and where Mode S is mandatory (e.g. Germany), every airplane is visible like that. I think by now all radar units in Germany have Mode-S display capability.

Apparently they do. I am told that Swiss radar can also directly see ADS-B.

Peter,

However the end result seems to be exactly the same, when one looks at the capabilities of the various plane spotter boxes e.g. Kinetik which can see both kinds of traffic. I know, from a friend, that he can see me flying around, my position, pressure altitude, ground speed, aircraft reg, even though I am definitely “elementary Mode S”, with no GPS data going into the GTX330. If I had GPS data going in, my lat/long would get transmitted precisely but I am not sure it makes any real difference to these boxes (it would to TCAS usage of course, but exactly who has ADS-B-capable TCAS? Definitely not airliners).

Um, that sounds not very credible. Either your plane emits ADS-B packets with position e.t.c. or those spotter platforms have no way of seeing you, at least Flight Radar hasn’t. There are some experimental platforms which try to triangulate the data but what I have seen from them is not very reliable.

ADS-B is extremely useful for traffic avoidance. Quite a few GA Traffic monitors are relying only on ADS-B so whoever has that capability will display on sets like Power Flarm, Garrecht, Avidyne and other such displays. The beauty of it is that we do not NEED any feed provided or refused by the powers that are, once a plane transmits ADS-B all you need is a display to show them!

So a GNS/GTN box, with a separate 1090ES ADS-B receiver, can provide traffic info by itself?

Yes. Without any ground feed. So actually it may well be more important to get it in Europe than in the US seeing the attitude we face.

Presumably, Avidyne’s claim of ADS-B capability (one day) is that a similar 1090ES receiver could be connected to the TAS605 and then the ADS-B derived traffic could be displayed on whatever the existing display device is?

ADS-B is the cheapest and easiest way to do that as all you need is a receiver and a linked GPS. Heck, this even works on ipads and the likes with some receivers out there on the market, of course dedicated devices are better.

I am the last guy to buy into new technologies fast and furious, but if there has ever been anything recently which did make sense to me it was to buy an ADS-B out capable transponder very early and get ahead of the game for a change.

NC Yankee,

Note, the airlines have no interest in TISB or weather in the cockpit as they have on board radar and TCAS. If the EU is airline oriented, these types of services are not needed and makes ADS-B In much less desirable for the GA pilot. Here in the US, the infrastructure of some 800 GBT locations is largely installed and GA gets more benefit from the system than the airlines. Airlines have not yet seen a financial case for ADS-B In.

Actually, I think the opposite is true. As opposed to the services available in the US, ADS-B is the ONLY reliable way to get traffic information in Europe as it is stand alone and does not require any ground service. All that is needed is an ADSB-Out capable transponder and a monitor on the plane which can read the ADSB-Signals and display them. I use Power Flarm and it works REALLY well with ADS-B equipped airplanes.

While we in Europe can’t receive ADSB-Weather and the FAA data which can be received via the Garmin GDL39 or the XGPS170 and all these devices, they still will receive traffic information from any ADSB-Out equipped airplane. That is most airliners and an increasing number of GA planes. Personally I think it is more responsible to equip your plane with this feature as it will make you visible to these devices. Power Flarm as one is quite popular here, so are others like the now defunct Zaon or the Monroy receivers. They all rely on ADS-B out.

The airlines are already required to have TCAS II and get alerts and RA’s now. ADS-B In does not add any capability for them they don’t already have. At this point, ADS-B is not approved for RA, just as an aid to traffic acquisition. An advanced TCAS can be implemented to take use of the information. ADS-B Out is for surveillance and the airlines are required to have it in certain airspace. 1090ES ADS-B Out is in its third generation (RTCA DO260 is 0, DO260A is 1, and DO260B is 2.). Most of the systems installed in the airlines are version 0 and 1. The US airspace requires 2 starting in 2020. Only version 2 systems will be able to be used by ATC.

So a GNS/GTN box, with a separate 1090ES ADS-B receiver, can provide traffic info by itself?

Presumably, Avidyne’s claim of ADS-B capability (one day) is that a similar 1090ES receiver could be connected to the TAS605 and then the ADS-B derived traffic could be displayed on whatever the existing display device is?

Any 1090 MHz receiver can receive and decode ADS-B. The GNS/GTN boxes support a standard interface for TAS/TCAS traffic and if the receiver constrains itself to using this interface, air to air reception and display on the GNS/GTN is feasible. ADS-B has additional capabilities not supported by the TAS/TCAS interface and is available for the GNS/GTN in a proprietary interface used by the GDL88. So to get the best support, one would have to reverse engineer this interface.

I doubt just having an ADS-B receiver on board would be useful as so few aircraft that represent a target threat have this capability. In the US, maybe 5 % and this is optimistic. There are many portable units available today in the price range of 600 to 900 USD that display on the iPad or iPhone. Since 95% of the traffic is not equipped, the GBT is needed to fill in the enormous gaps with the TISB service. If the EU doesn’t implement this service, then ADS-B is next to useless for traffic.

BTW, a portable ADS-B receiver in the US, although useless for traffic unless the aircraft is equipped with ADS-B Out, is very useful for weather. The reason it is useless for traffic unless own ship has ADS-B Out installed is that the GBT will only broadcast TISB targets that are in the vicinity of a valid client that has ADS-B Out. The TISB service provided by the GBT is +/- 3500 feet and within 15 NM of a client. I have ADS-B Out, so both my portable and my installed systems show all relevant traffic.