Cheap ADS-B in/out solution for traffic information

Hi Florian, You can use the ADS-B In and FLARM In part of SkyEcho 2 in whole of Europe. Only ADS-B Out from SkyEcho 2 is allowed only in the UK for now. The EASA working group Electronic Conspicuity is using the UK draft as input document together with an Eurocontrol document in order to work on an European Electronic Conspicuity standard. Please give the EASA working Group some time to work out the low power device standard for Electronic Conspicuity.
Find SkyEcho on our European web site: https://uavionix.store/general-aviation-ads-b-transceivers

Florian, you should distinguish between a safety device (collision avoidance system) like FLARM and 'showing traffic on the iPad', the latter being for entertainment purposes. You do NOT want to be looking at a screen when you should be looking out, which is especially true in high traffic density environments. Many aircraft will still not be shown by any system and the only way to have a chance to see them in time is by looking out. FLARM will warn you when you are about to collide so you can take action when needed. More than 50% of GA in Europe have FLARM already (less in the UK), which is many more than ADS-B Out (which is essentially limited to airliners and business jets).

Regarding your approval question, FLARM is approved by EASA for installation as either a Standard Change or a Minor Change. There are no restrictions, FLARM is recommended by every EASA inspector I have spoken to.

First word of caution, I'm a FLARM user and I think it is a great system. I see some limitations and questions that would have to be addressed before it could become a global standard for general aviation.

Although I concur with the benefits of FLARM for many users, I still find some subjects that are giving me food for thought.
First of all, FLARM is a private venture. The core code is owned by private interests. This is a bit troublesome for me. Owners could make any decision regarding FLARM in the future and no one could protest.

Secondly, FLARM has inherent limitations that lie with its own standard. Some aspects should be researched before making it a standard. I'm myself a FLARM user when I fly Gliders. In some cases, some traffics are not detected or some indications are not clear (swarm flying). I do agree that installations should be checked before this becomes a FLARM standard issue. (antenna diversity, electric wiring etc)

Thirdly, Frequency protection is one of the biggest obstacles that have to be overcome before any traffic system becomes a standard for aviation. And when I say aviation, I mean Commercial Air Transport (CAT) and General Aviation (GA, all components, including ultralights, balloons, Gliders) and UAVs of all sizes.
https://www.anfr.fr/fileadmin/mediatheque/documents/tnrbf/TNRBF_2020-01…
This link is the French version of frequency attribution. Each country publishes one after all members of a region have agreed between them.
As you can see, the frequencies used by FLARM are not reserved for aviation use and could be reattributed (low probability, but exists), requiring a change of hardware.

Fourth: Installed base. I believe firmly that all of aviation should benefit from new services:
Traffic avoidance
Live Weather reports
Direct messenging to an aircraft by ATC

These services are desirable by all airspace users: CAT, GA, and UAVs. Even if CAT and airlines claim that they are not interested, just think about the workload that could be alleviated for ATC just by not having to research TAF and METAR and radio them to RyanAir and Easyjet (we have all heard them requesting these on frequency!). Weather information, Restricted flight zones (European TFR's), are some of the services that benefit to all classes of users. Don't even have to think about traffic!

For this to benefit all, all information must be sent using frequencies that are protected for good for aviation use. Otherwise, surprises will be looming over the horizon. Not convinced? It has happened before and it has cost GA operators a lot of money. Remember FM immunity?
We ended up spending thousands of euros (national currency at the time) to shield our radio equipment from FM broadcasting stations that wanted more output power. Let's pause a second and remember the facts. Aviation frequencies (voice, VOR, VORTACS, ILS) are protected and reserved for the exclusive use of aviation. Has been the case since the sixties. In the early '80s, FM radios bloom all across Europe. Sometimes their transmitters are located not far away from airports and airfields. There is a (small) danger that their transmitters are going to jam the aeronautical frequencies (power to distance ratio not favorable as the frequencies are close).
In the end, because nobody in the aeronautical world (ATC, NAAs, pilot defense associations) paid attention to the requests regarding frequencies attribution and power limits when close to an airport, Pilots ended up having to pay heftily to continue to use the frequencies reserved for their use. 10K€ per plane was not unusual...
Sheer Madness.

So our future, in my humble opinion, lies in a system based on the convergence of multiple standards.
1090 ES ADS-B out: already mandated for CAT, worldwide standard
978 UAT ADS-B out for GA: allows GA to transmit ADS-B signals without saturating 1090 ES around large airports. Standard is proven and can be used by GA and UAVs of all sizes
978 UAT ADS-B in for all: allows receiving data in the cockpit regardless of the size of the aircraft. Compatible with electrical systems of all aircraft, including ultralights, gliders, balloons, etc.
Primary Radar: detection of non-transponding aircraft.
Secondary Radar: All 1090 ES, Mode S basic, Mode C, Mode A traffics.
FLARM: input of FLARM signals reported by the ground station network and isolated aircraft (air to air when not in range of ground station)
Weather Data

Combine all these signals into one stream available to cost-effective (less than 10K€ per ground station) and you have created the ultimate system for all participants

Furthermore, the costs are minimal to all. All GA aircraft can receive UAT information with weather and traffic, airliners already read ADS-B traffic and could use UAT receivers (cost as low as 200 USD) to benefit from weather reports.

The key is there: use the right technology in each segment of aviation, aggregate all signals and rebroadcast for the benefit of all.

Emmanuel,

FLARM is already the de facto standard for collision avoidance for GA. When you say "standard", you are probably thinking about making it mandatory (compare with TCAS, GPWS). EASA does not designate non-mandatory standards. I don't think it would be beneficial to make FLARM mandatory. We have all benefitted from the innovation that has come from FLARM in the last years, thanks to it being a non-regulated standard. The reason aviation technology is decades behind the rest of the world is exactly because of the "global standards".

Regarding the commercial aspect, this is actually nothing in comparison with TCAS, GPWS, etc. which is also commercially protected by patents, etc. And in any case, making FLARM mandatory/regulated with thousands of pages of standards documents would make it WAY more expensive than today.

Frequency protection is not an issue at all. 868 MHz (which FLARM uses) is protected in Europe in terms of how and how much you can transmit, to make sure it can be used by everyone. Because of so much equipment using this frequency, it would essentially be impossible to change this. 1090 MHz is actually less protected and can easily be congested.

Regarding 1090ES and UAT, those are for ATC purposes and not collision avoidance systems. By installing FLARM, you are not just making sure that you can avoid collisions, but also helping others do the same.

Hello William,
I don't think our thoughts are far from each other in fact.
What I am advocating is the convergence of existing standards.
We all know that 1090 MHz is already congested as some airports experience difficulties to visualize all traffics using that frequency.
We also know that the USA while researching the best way to improve and modernize ATC services reached the same conclusion and decided to fraction the mandate for equipment. Anything flying above 18000 ft would go to 1090ES while the others are advised to consider UAT on 978 MHZ.
The FAA, exactly as EASA, Eurocontrol and any other European agency needs to provide a cost/benefit study for all stakeholders before any mandate can be written in stone. While doing this the FAA considered that in return for the investment that was to be made, additional services should be provided to the users. Hence traffic service and weather services free of charge when they were already available by other means (and a lot of money).
So how does ADS-B look now in the USA? For a minimal investment, all stakeholders receive free of charge benefits.

What I advocating is that there is a chance, today, to consider that there are some existing technologies that could benefit all users (not only GA, but CAT also) by being implemented in an astute manner.

Regarding the services considered, we always look at them to find a unique standard that will provide a "one size fits all" solution.
I believe that this is wrong. We should try to design a system that accepts different technologies and broadcast them to the planes, whatever their size.
This includes Primary radar, secondary radar, ADS-B out 1090, ADS-B out 978 UAT low power, Flarm and keep our minds open for the future.

By broadcasting a composite signal, encompassing all these sources, we would serve aviation as a whole and, at the same time, allow UAV manufacturers of all sizes to participate in the system.
The costs, technical constraints (electrical consumption and others) would be minimized for all users.
I am in no way opposed to FLARM. It is installed in my plane. For one reason: I also fly gliders and fly with my plane regularly in areas where gliders are omnipresent (French, German, Austrian and Swiss Alps).
In these areas, Flarm is a great tool to avoid tow planes and gliders. But the reality is that, outside of this population and areas, my FLARM transceiver is very quiet. We fly about 300 hours per annum with our plane, all over Europe from the Spitzberg to northern Africa and for the immense majority of the time, the transceiver is silent.

My point is that we should aggregate information available and send it to the planes and not only rely on one system that only covers traffic avoidance between some of the sky's users.

Ground stations that can aggregate all the sources are cheap when considering the usual costs in aviation. For less than 10'000 euros, a professional ground station can be installed, will all the redundancy needed. depending on altitude, it will be received between 40 or 45 nm up to 200 NM. Country per country, the number of stations needed on the ground is pretty low. And it will allow any type of aircraft, UAV, ballon, or glider to benefit from the information generated by any type of transponder, all the information gathered by ATC, all the FLARM position reports. Compare the cost of a ground station to the savings generated by replacing costly ILS by RNP approaches. Each country could probably finance all the ground stations needed by using a portion of the savings.

Convergence is a sweet thing that could benefit to all and allow all users to choose what kind of technology is the most suited to their needs and means. A 200 USD UAT receiver could be beneficial to glider pilots that are already FLARM equipped, as they would see non FLARM traffic and get weather information. I'm just concerned that we try to reinvent the wheel again and let the mermaids sing into our ears, proposing new unproven standards.

Emmanuel,
I do not wish to insult you intelligence but your ideas for rebroadcasting will not fix the interoperability problem.
The ASA MOPS for EVAcq (ED194) requires CDTI to reject any traffic data that does not have a system design assurance of 1 or greater and FLARM would not reach SDA 1.
Your Information about the situation in the U.S. is wrong too, the FAA has mandated transponder mandatory zones within 30nm of major airports for several years, the only difference is that they must now include ADS-B OUT.
Finally your estimate for installing a ground station is out by at least a factor of 10.

Hello Ade,
Relying solely on the way things were done in the past is the best way to make sure that progress can't happen.
I'm pretty sure that when the first guy came up with the idea of radar, they were a lot of people looking at him and telling him they didn't want to insult his intelligence

The fact is that technological progress relies on the fact that one accepts that there will be a moment when we do something that has not been done before.

I'm far from being an expert in ATC management, but technology is an area that is not totally unknown to me. From a strict technical standpoint, aggregating different sources of data that report traffic positions, headings and speeds is pretty trivial.

I remember an experiment a few years ago when a feed coming from networked flight simulator enthusiasts was sent out to unsuspecting air traffic controllers. It was all a prank obviously, but before the panes started to act foolish, there was a period od an hour and a half where the controllers never suspected that their echoes were not real aircraft.

I also had the privilege of visiting a naval simulator designed to teach advanced ship handling.
More details here:
Sea School Alabama unveils new simulator
Friday, 11 October 2013 | Navigation, Autonomy & New Technologies
VSTEP has announced that SeaSchool-Mobile, in Alabama, has acquired a NAUTIS Full Mission Bridge Simulator and Instructor Station.

The Rotterdam-based developer says that, together with its US partner Annapolis Simulation, it is installing the simulator in the school’s campus in Bayou La Batre, near Mobile.

The DNV certified NAUTIS Full Mission Bridge Simulator features a 180° external view angle, which exceeds the minimum 120° exterior view angle required for DNV Class B simulators. It allows for training in Advanced ship handling & manoeuvring, ECDIS Model Course 1.27, Radar/ARPA Model Course 1.07, VHF Radio Communications, Navigational Instruments (GPS, AIS, Echo Sounder, and Speed Log), and GMDSS Radio Communications Model Course 1.26.

Victor Tufts, VSTEP North America sales manager, said: “Together with our North American partner Annapolis Simulation, we are very happy to include the SeaSchool in the NAUTIS family.”

“The acquisition of this Simulator and Instructor Station guarantees realistic simulator training of the highest quality for the SeaSchool students for years to come.”

SeaSchool provides US Coast Guard approved courses and STCW-95 compliant training.

What was the most interesting for me was how all the various data streams were integrated together and came out as real-life experience.

So, to get back to the subject we are all interested in, what is the real problem?
According to your answer, the current regulation doesn't allow some of the components of the ideal future anticollision and weather broadcasting (more specifically FLARM). So what? Does it prevent us from taking a closer look at the goal and, maybe, realize that regulations should be changed? I don't believe that FLARM is solid enough to become a standard for the whole of GA. For many reasons. But one has to be pragmatic. There are thousands of gliders, tow planes and other aircraft that are already equipped. They have proven, beyond doubt, that the system works well for that category of aircraft. So, if we were to broadcast the signals of the FLARM network, would we be endangering the other aircraft? When flying in the Alps area, I get warnings from ATC, they will tell me that there is one or multiple gliders in my area. Depending on my track and altitude, it may be interesting for me or irrelevant. These warnings are not of the utmost precision and rely on the fact that the glider has a functioning transponder onboard, in most of the cases. In real life, I get more warnings from the FLARM system than from ATC. Either ATC has not bothered beyond a "Gliders in the vicinity, exercise caution and keep a good lookout", or they have no knowledge of this traffic. So I'd rather have the option to have an inexpensive receiver onboard that will allow me to get information from various sources.
Again, aggregating different data sources and broadcasting them is not a problem today. Current regulation is. EASA has started to take a new approach towards uncertified (under current rules) systems. If this approach increases the safety of flight, why would we not change the regulation?

Concerning the situation in the USA... I happen to be a US citizen that has decided a long time ago to live in Europe. At least half the time, the rest of my time is spent in the USA. I fly quite a bit there a bit on various types of aircraft. Even if I agree with you on the point that there was a. mandate for mandatory xponder carriage in certain areas,
I fail to see your point. The situation is clear: to enter controlled airspace, where an xponder is needed, you need to broadcast an ADS-B signal, since the 1st of January 2020. Depending on the type of aircraft you are flying and its performance, you can choose the standard used to broadcast, choosing between 1090ES and UAT. It simply shows that the system has already been tested in real-life conditions and it seems to functions pretty well.
UAT, 1090ES, Mode S, mode C are aggregated through a ground station network. All participants will find some advantages and benefits using the system. From balloons and ultralights up to airliners.

Regarding the costs of ground stations, I can assure you that the amounts cited for a ground station are realistic. It is not because, until now all those in charge of approving budgets have accepted stratospheric prices (think of the infamous toilet seats for certain strategic bombers) that there isn't a possibility of building the same kit for a realistic price. When I look at the number of times an ILS, VOR, lighting system, PAPI or PCL is on the fritz for more than 24 hours on general aviation airfields, I would rather have three or four redundant cheap systems that a dual expensive one!
Again, the world is moving around us and we need to adapt. And we wan to embrace change when it means added safety and benefits.

As an aircraft owner, I have. been financially shafted in the past:
FM immunity 7000 euros
Mode S mandatory for IFR 7150 euros (and for four years was told by most smaller ATC centers that had not upgraded their system to Mode S yet...)
8.33 kHz radios would have cost a minimum of 6500 euros if I had not chosen navigators that, luckily, had that capability.

In short, none of these was a benefit to me as a pilot or aircraft operator. I was told to make the changes and if I wept, I wasn't even offered a used Kleenex.

What did I receive in exchange? A better service? Priority routing? Rebate on fuel? Access to more airports? Traffic information? Weather in the cockpit?
None of the above. And I had to pay for all this because people in control where frozen in their certainties and habits and always prioritized airlines needs before remembering that GA exists.
When airlines are given the mandate to carry TCAS for safety, they just turn around and calculate how many cents per passenger it is going to cost. For us, we write a check, from an account that has already been depleted by VAT costs and taxes. I tried sending myself an invoice to see if I could sit better, but it did not work.

I don't want to be a dinosaur, they tend to disappear.
I want our authorities to look at the future pragmatically and embrace changes when there is a case for added safety or benefits for the end-user. I don't want to be patronized or lied to. It is time to put all the options on the table and make decisions that benefits all stakeholders.

Emmanuel,

I think you have the right intentions, but you seem to be mixing up different technologies with widely different purposes, requirements, and implementations. You advocate the “convergence of existing standards”, but I don’t understand what you mean by that, and I’m afraid you don’t understand it yourself either. I don’t blame you because you are certainly not the only one. But you cannot just “converge” standards/technologies for the same reason you cannot broadcast weather on TCAS, do voice communication over GPS, or stream a movie using NDB channels. Even when looking at seemingly similar technologies like ADS-B and FLARM, they don’t mix well together. ADS-B was developed for ATC purposes with several miles of separation. FLARM is a tactical collision avoidance system with meter accuracy. PowerFLARM systems receive ADS-B Out and integrate this into the collision algorithms, but this has several challenges as ADS-B was not developed for this purpose (e.g. timing, position accuracy). FLARM has actually described this pretty well in a white paper:

https://flarm.com/wp-content/uploads/man/FTD-062-System-Design-and-Inte…

This becomes an even bigger problem e.g. when trying to relay the data using ground stations. And honestly, why would you? It’s not the same data and it cannot be translated. There is a reason that standards exist. Over 50% of GA in Europe already have FLARM, and there is no reason for the other half not to have it. ADS-B does not solve any problem in terms of collision avoidance.

If you have been flying over Europe and not seen much traffic when not on a collision course, this is how the system is designed (you can, however, change this in the configuration). But your FLARM transceiver is working also when nobody is around.