ADS-B for GA in Europe?

[betterfromabove]

Hi,

Can anyone enlighten me on whether we shall see ADS-B being taken up by GA, especially the light end, in Europe in the forseeable future?

In the US, it seems to be being touted as the solution to a series of potential ills for GA pilots (navigation, collision avoidance, comms in remote areas, distress calls, infringement avoidance) with wonderful portable tablet or fixed unit displays.

Is it really such a silver bullet?

In the US, there appears to be an infrastructure already being built for all to use. Any sign of this on the cards for Europe?

And devices for the US seem to be retailing in the high single digit $1000's, so does this mean substantially more in Europe? And hence likely out of reach for many GA's?

What are the technical considerations and the likely evolution? Are the devices going to be feasible to install in light GA (SEP's or lighter)?

Appreciate any info.

All the best,
BFA

[peterh337]

Very unlikely to be mandated for GA here.

Even Mode S is not mandatory for VFR for many/most areas.

You can already achieve much the same thing by enabling what is in effect partially Enhanced Mode S, by allowing your transponder to radiate your GPS position. AIUI, ADS-B gives you just that, except it radiates your position continuously even if you are not interrogated by SSR.

Yet, any form of Enhanced Mode S is explicitly banned by EASA, on aircraft on which it is not mandatory :)

I recall going to a Eurocontrol presentation in 2008 where they said they want to dismantle primary radars to save costs and replace them with ADS-B. These people live in their own world...

[Rod1]

You will find ADSB will be in the news a lot over the coming months.

Rod1

[mm_flynn]

In the US they have decided two key principles

1 - To move to an ADS-B infrastructure for the primary source of ATC data (I believe with a 2020 change over) so everyone who participates in the ATC environment will need a GPS as a source of position coupled to an ADS-B transmitter. This will cost some good chunk of money for GA to comply with and GA has negotiated getting extra data broadcast. Also, to provide ATC with data across the country they need remote receivers and these receivers are configured as repeaters (so they re transmit the ATC image of targets so that ADS-B in people can see the two different flavours of ADS-B plus Mode-A/C traffic)

2 - The US has also decided to have a two tier ADS-B infrastructure. One using the Mode-S frequency/protocol and one using a different frequency. The Mode-S one has the advantage of being consistent with world wide CAT equipment, but has the disadvantage of very limited bandwidth (i.e. no uplinked weather). The other system (UAT) has much higher bandwidth and the ability to provide all of the sexy features described in the OP.


It will come as no surprise that the European implementation is scheduled further into the future and is only based on the Mode-S datalink with none of the extra features (beyond being able to see all the other ADS-B traffic - but not I believe a retransmission of legacy Mode-C targets).

[Denti]

Yet, any form of Enhanced Mode S is explicitly banned by EASA, on aircraft on which it is not mandatory


No, it is not banned. However the technical and therefore financial barrier is high enough to make it impracticable. However, Enhanced Surveillance delivers more information than needed for simple ADS-B out (except the position of course). ADS-B out can be achieved pretty cheap currently. As can be a simple ADS-B in traffic display. For example powerflam is available for less than 1k€ and displays flarm data as well which is used in over 18.000 glider and GA airplanes worldwide, most of them in europe.

Isn't the Mode S extended squitter (1090MHz) required above FL240 in the USA for ADS-B? Which really does not matter for most GA airplanes of course.

[mm_flynn]

No, it is not banned. However the technical and therefore financial barrier is high enough to make it impracticable. However, Enhanced Surveillance delivers more information than needed for simple ADS-B out (except the position of course). ADS-B out can be achieved pretty cheap currently. As can be a simple ADS-B in traffic display. For example powerflam is available for less than 1k€ and displays flarm data as well which is used in over 18.000 glider and GA airplanes worldwide, most of them in europe.

Isn't the Mode S extended squitter (1090MHz) required above FL240 in the USA for ADS-B? Which really does not matter for most GA airplanes of course.
A more precise version of Peter's statement could be

Under the existing EASA approvals for installing a Mode-S transponder providing elementary surveillance data, it is not permitted to radiate additional data elements such as position. Not withstanding that is what the Garmin 330 does if coupled to a GPS (for example to provide the ground air switching) and which is standard configuration in FAA aircraft.

[peterh337]

I think Denti you need to become aware of the issues surrounding the GTX330 and connecting NMEA data to it :)

Posts crossed with mm_flynn :)

There is new firmware for a GTX330 which solves that "European issue" but of course all "foreigners" are unaware of it to start with and it doesn't do any harm whatever.

[Daysleeper]

Did I not read something in a magazine recently that NATS had taken up the challenge of electronic conspicuity for light aircraft? Following the success of their other projects they were looking at a light weight low power/cost ADS-B based product.

Ah ha! found some of it in December 2011's iAOPA In the UK, NATS is attempting to drive R&D on the issue. But the level of European or government funding is almost non-existent, again in stark contrast to the USA. In some cases, we need to actually disable the function in our US-specified box when flying in Europe!

[Denti]

Interesting issue then. We got a Becker transponder installed and certified by the local authority (LBA) in 2006 which includes a connection to the GPS and position report available via the extended squitter. Might be that that was a grandfathered installation, but it is still flying today and allows ADS-B out.

Interesting that EASA made that into a major issue now, but the reason might be the issues around position data integrity which most if not all GA installation do not provide which means that ADS-B reports have to be discarded by ADS-B in systems anyway.

Interesting though that ADS-B out will be mandatory in less than three years for certain aircraft (more than 5,7t or 250kts cruise speed) within europe but the certification standards are not yet published.

[peterh337]

the reason might be the issues around position data integrity which most if not all GA installation do not provide which means that ADS-B reports have to be discarded by ADS-B in systems anyway.Can you elaborate on why the data integrity is a problem?

Interesting though that ADS-B out will be mandatory in less than three years for certain aircraft (more than 5,7t or 250kts cruise speed) within europe but the certification standards are not yet published.

Those have mandatory Enhanced Mode S so radiating the stuff the whole time is a small step.

[Rod1]

“the reason might be the issues around position data integrity which most if not all GA installation do not provide which means that ADS-B reports have to be discarded by ADS-B in systems anyway.”

All ADSB out via certified mode s transponders will have SIL enabled which will handle this.

Rod1

[peterh337]

The data integrity issue is nonsense. In all cases of Enhanced Mode S, the data comes from a collection of avionics boxes, including an airdata computer, and it is concentrated at the transponder. It either works or it doesn't.

Quite what ATC use it for in the GA case (say TBM850 / light jets) would be a good question.

[ATCast]

There is some debate going on about how to handle GA and ADS-B in Europe.

ADS-B is a distributed cooperative type of surveillance. This has its advantages and its risk. One of the risks is that (uncertified) installations transmit misleading data, which could lead to misidentification, loss of separation or worse. Therefor it is undesirable that GA is equipped with uncertified ADS-B transponders. At this moment there is a lack of certification standards for GA type aircraft. Also the technical standards are aimed at transport aircraft. Low power transponders or pure ADS-B transmitters are not yet standardised.

I don't expect Europe to go down the US route and have 2 separate and incompatible ADS-B systems. If GA in Europe is going to be ADS-B equipped, it will be on 1090ES so that everybody is visible to everybody.

To experience full benefits of ADS-B, everyone it the airspace must be equipped with ADS-B so everyone can see each other on a traffic display.
What to do? Mandate everybody to have ADS-B out including GA. Close down parts of the airspace for non-ADS-B aircraft?

In short, it's not very straight forward, and there are many decisions to be made. I don't see ADS-B mandated in Europe for GA very soon.


Although the rest of this post is a bit beside the OP's original question, I'll reply to some of the ADS-B related comments made here.



peterh337: I recall going to a Eurocontrol presentation in 2008 where they said they want to dismantle primary radars to save costs and replace them with ADS-B. These people live in their own world... Primary radars are not likely to be replaced by ADS-B, they serve a different purpose (security). A number of Secondary and Mode S radars is likely to be replaced.


Denti: Interesting though that ADS-B out will be mandatory in less than three years for certain aircraft (more than 5,7t or 250kts cruise speed) within europe but the certification standards are not yet published. ADS-B will be mandatory in European airspace for aircraft over 5.7t MTOM or 250 kts max cruise speed build after January 8th 2015. After December 7th 2017 all aircraft above 5.7t MTOM / 250Kts must be equipped. EASA is taking a long time getting the CS published indeed, but manufacturers seem to be aware of what will be required and are developing their systems.

Denti: the reason might be the issues around position data integrity which most if not all GA installation do not provide which means that ADS-B reports have to be discarded by ADS-B in systems anyway. peterh337: Can you elaborate on why the data integrity is a problem?Data integrity is one of the concerns for GA installations. GPS position can be calculated when a signal is received from 4 GPS satellites. If one of these signals is faulty (e.g. due to satellite orbit deviation, satellite failure, spoofing etc) the measured position will be off without the user knowing it. Therefor aviation receivers have RAIM, (Receiver Autonomous Integrity Monitoring) which requires at least 5 satellite signals. If all five (or more) signal are consistent with the same measured position, all is ok. If the signals are inconsistent a flag is raised and the position data is not to be trusted. The maximum horizontal position error that could go undetected by RAIM is the called the Horizontal Integrity Limit or containment radius. This is send out in the form of a quality indicator by ADS-B. If there is no integrity information available from GPS, the quality will be 0 and the position data is not trusted. The NMEA data format for example does not contain Horizontal Integrity Limit and therefor NMEA based GPS units are not suitable for certified ADS-B.


Rod1: All ADSB out via certified mode s transponders will have SIL enabled which will handle this.SIL is Source Integrity Level (in 1090ES version 2) and indicates the robustness (probability of exceeding the containment radius without raising an alert) of the RAIM checks . It is one of the quality indicators that is transmitted, others being NIC (position integrity), NACp (position accuracy), SDA (system design assurance)

peterh337: The data integrity issue is nonsense. In all cases of Enhanced Mode S, the data comes from a collection of avionics boxes, including an airdata computer, and it is concentrated at the transponder. It either works or it doesn't.There is a difference between data integrity and system integrity. Data integrity refers to undetected corruption in the original measurement (e.g. GPS position or pressure altitude). System integrity refers to corruption during the transport and processing of the data. You seem to be talking system integrity issues. Unfortunately it is not a case of "it either works or it doesn't", I have seen cases where misleading data was sent during a particular flight phase, which looked credible on first sight but was faulty on closer inspection.



mm_flynn: It will come as no surprise that the European implementation is scheduled further into the future For aircraft above 5.7t MTOM / 250 KTAS Europe is ahead of the US. As said before, there is no schedule for GA.

[peterh337]

One of the risks is that (uncertified) installations transmit misleading data

Why would a certified installation be accurate? The difference is almost wholly just paperwork (and price :) ).

If one of these signals is faulty (e.g. due to satellite orbit deviation, satellite failure, spoofing etc) the measured position will be off without the user knowing it.

How will he be navigating then?

[ATCast]

Why would a certified installation be accurate? The difference is almost wholly just paperwork (and price http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif ).Certainly it is not holy writ that certified installations are perfect. However, many installations could be thought off (and some are flying right now) that send out ADS-B data that is misleading. Certification is one method of ruling out installations that just don't work.

How will he be navigating then? What happened to VORs/ NDBs / DME's/ dead reckoning / eyeball & the good old map? Are you implying that GPS without RAIM should be used as sole means of navigation?

[mm_flynn]

For aircraft above 5.7t MTOM / 250 KTAS Europe is ahead of the US. As said before, there is no schedule for GA.
While I appreciate everyone with Mode S Enhanced be transmitting an accurate position by 2015, I am not sure this is a material step in the movement from SSR to ADS-B as the primary means of providing location data to ATC for separation of aircraft.

It is difficult for me to see the advantage of moving to ADS-B for separation of aircraft over 5.7 tonnes and staying with SSR for less than 5.7 tonnes. As I understand the US position is that in 2020 ATC will use ADS-B instead of SSR and everyone with a transponder will need to be ADS-B out equipped. There will clearly remain a need for primary radar for security and maybe for providing basic lateral tracks for non-transpoinding aircraft. The European 2015 data seems an isolated requirement on an undefined (and probably distant) implementation plan.

[peterh337]

Certification is one method of ruling out installations that just don't work.

How does it that work?

What happened to VORs/ NDBs / DME's/ dead reckoning / eyeball & the good old map? Are you implying that GPS without RAIM should be used as sole means of navigation?

For a brief moment I thought you worked for Eurocontrol because you write in the "right kind of language" but obviously I was wrong, because you are unaware that for IFR in CAS in Europe one needs BRNAV capability, for which the only means of compliance is INS or GPS.

Also it's obvious you are not an IFR pilot, because GPS (with or without RAIM) is used as the sole means of navigation routinely (and 100% legally).

It now sounds like you are an instructor, or an FTO ground school teacher, perhaps?

The European 2015 data seems an isolated requirement on an undefined (and probably distant) implementation plan.

I think so, but you could say that for a lot of stuff coming out of Eurocontrol.

They are still on 10,000 VLJs flying out of Luton :) Mind you, so is most of Swanwick, I believe :)

Primary radar will never go away for national security reasons alone, and then the extra cost of the SSR bit bolted on the top is.... not a lot. Actually the bulk of radar data collected around say Europe is not shared with civilian ATC, so if one was looking for savings... :)

[ATCast]

My comments were made with
GA, especially the light end in mind.
We're now drifting towards the high end.

for IFR in CAS in Europe one needs BRNAV capability, for which the only means of compliance is INS or GPS.Navigation is not my speciallity but IIRC B-RNAV requires 5 NM track keeping accuracy and compliance can be achieved by DME/DME and probably by VOR/DME as well. Do you know which AMC covers B-RNAV, I did only find the RNP-AR one.
Anyway that is not sole means GPS, but primary means. When GPS fails you can fall back on alternative systems that don't meet the requirements but at least give you a good sense of where you are.

GPS (with or without RAIM) is used as the sole means of navigation routinely (and 100% legally).I doubt that, but again navigation is not my speciallity. GPS as primary means seems reasonable provided that you have RAIM (and you usually have it). But I don't believe that you don't have a clue where you are if GPS fails, at least I hope so.

ATCast

[peterh337]

Navigation is not my speciallity but IIRC B-RNAV requires 5 NM track keeping accuracy and compliance can be achieved by DME/DME and probably by VOR/DME as well.

That is incorrect, both legally and practically.

Legally, you need a BRNAV compliant nav means which in the GA context can be met only with an IFR approved GPS, or with a BRNAV approved (ancient) KNS80 installation with antenna filters for FM immunity.

Practically, ATC treat all that airspace as RNAV i.e. most of the waypoints you will be given will be either virtual waypoints (not navaid based or navaid-relative referenced) or they will be navaid names but the navaid itself is way out of DOC (e.g. a VOR 200nm away).

There is also no way to navigate using DME/DME - except using an FMS with an INS with DME/DME corrections, which is not GA. Only high-end bizjets and above will have that. Unless you fancy flying your entire route as a series of DME arcs ;)

Anyway that is not sole means GPS, but primary means.

That is complete bollocks. There is no concept of "primary". The regs (for non AOC ops) dictate equipment carried, not equipment used. You must be a PPL instructor :)

When GPS fails you can fall back on alternative systems that don't meet the requirements but at least give you a good sense of where you are.

Actually, in BRNAV-mandatory airspace, you pull out your backup GPS and use that as a DCT box :) If you have lost all GPS reception, you advise ATC that you have lost RNAV capability and need VOR-VOR routes, or vectors. This is very rare (GPS is extremely reliable) but it happened to me once (http://www.peter2000.co.uk/aviation/corfu/index.html) in Italy and I got assigned a different route with a higher MEA (FL160 instead of 140, IIRC).

[Rod1]

“Therefor it is undesirable that GA is equipped with uncertified ADS-B transponders.”

I am confused by that! In Europe we are using Mode S transponders with extended squitter to emit ADS-B out. I think all the transponders available are certified?

I would have thought that uncertified installations set with SIL=1 would have made the sky much safer than no ADS-B out at all? This appears to work in the US. In the UK I was under the impression that ADS-B was not in use by ATC apart from North Sea helicopters?

Rod1

[peterh337]

Don't worry - I think that poster is a bit of a troll (http://en.wikipedia.org/wiki/Troll_%28Internet%29).

What is needed to get a standard GTX330 to emit continuous ADS-B?

I think that if one connects NMEA data to one of its RS232 inputs, it will just radiate the lot, including (usefully) your GPS position. There is no configuration (in the firmware I have, dated c. 2005) for excluding any specific labels. I believe that came in a later revision, to enable the use of GPS ground speed for automatic GND/AIR switching without radiating anything. Wigglyamp will know for sure.

[ATCast]

Therefor it is undesirable that GA is equipped with uncertified ADS-B transponders.I am confused by that! In Europe we are using Mode S transponders with extended squitter to emit ADS-B out. I think all the transponders available are certified?Sorry to cause confusion. You are correct that the transponder is certified. The certification usually covers Mode S, as described in (E)TSO-C112.
However in general it does not cover the ADS-B specifications (E)TSO-C166b.

Some Mode S certified transponders radiate extended squitters, but are not ADS-B certified. Potentially they could send out corrupt ADS-B data, and in a few cases they do so.

In addition to corruption of data by the tranponder, the attached systems can cause problems. For example the time between the validity of the GPS position and the moment that it is send out by the transponder is too long in some systems.

At the moment all those issues are not really a problem since ADS-B is not used operationally within Europe. But to start operational use of ADS-B these problems need to be addressed.

ATCast

[Contacttower]

The only thing I'd be interested in is whether or not there is a possibility of getting weather etc through the system...are we likely to see that in Europe any time soon? Isn't the FAA planning to provide this for free to aircraft with the right equipment to receive it?

I have to admit I'm a bit behind with the details of this since it hasn't really received much coverage in the UK pilot community.

[peterh337]

For example the time between the validity of the GPS position and the moment that it is send out by the transponder is too long in some systems.

Can you supply more detals?

[betterfromabove]

Glad to see it's not just me that's been wondering about this technology and why once again there seems such a chasm between the US GA experience and the European one.

Thanks for all the informed and detailed responses - sure is valuable to not just me in understanding the question better.

One aspect only one post has touched on I think is the issue of fittability within the light GA fleet?

Notwithstanding the degree and richness of data being transmitted, what % of the GA fleet (in the widest sense...) might we expect to see able to fit this kit in 10 years time in the US.....and then in Europe?

Are there any devices out there viable for the fleet that currently is unable/unwilling to install Mode C? Or will ££/size/weight issues come into play in same way?

Thanks again,
BFA

[ATCast]

Peter, the concept of primary navigation does exist, and it is as you say not expressed in the form of equipment used, but of equipment carried. EASA probably thinks that if they make you carry a fallback system you will use it when you need it, even when they have not explicitly told you to do so. :ok:

I've looked up the AMC for B-RNAV, here is a section on GPS:

4.4.2.3 GPS
The use of GPS to perform Basic RNAV operations is limited to equipment approved to ETSO-C129a,
ETSO-C 145, or ETSO-C 146 and which include the minimum system functions specified in paragraph
4.2.1. Integrity should be provided by Receiver Autonomous Integrity Monitoring (RAIM) or an
equivalent means within a multi-sensor navigation system. The equipment should be approved in
accordance with the AMC 20-5. In addition, GPS stand-alone equipment should include the following
functions:
(a) Pseudorange step detection
(b) Health word checking.
These two additional functions are required to be implemented in accordance with ETSO-C129a
criteria.
Traditional navigation equipment (e.g. VOR, DME and ADF) will need to be installed and be
serviceable, so as to provide an alternative means of navigation.
That last sentence is there to make sure GPS is not the sole means of navigation, but the primary means. If you google "primary sole means navigation GPS" you will find more.

For a brief moment I thought you worked for Eurocontrolyou are not an IFR pilot
you are an instructor,
an FTO ground school teacher, perhaps?
You must be a PPL instructor
I think that poster is a bit of a troll (http://en.wikipedia.org/wiki/Troll_%28Internet%29).You seem to think quite a lot of me. :}
I am not a pilot myself, but I am involved in standardisation of ATM-technologies. The reason that I join the discussion here is to better understand GA point of view.

ATCast

[ATCast]

Quote:
For example the time between the validity of the GPS position and the moment that it is send out by the transponder is too long in some systems.
Can you supply more detals? If memory serves me right, the maximum latency time is 1.5 seconds for ADS-B installations certified for ADS-B-NRA (NRA = Non Radar Airspace, so ADS-B as sole means of surveillance). That is what is currently used over Hudson Bay in Canada for example.
That means that if the aircraft is flying at 500 Kts ground speed, the reported ADS-B position can be maximally 385 meter behind him.

For the European ADS-B mandate (so not targeting GA) the maximum latency is 0.6 seconds. For the aircraft flying at 500 Kts, the reported ADS-B position can be maximally 155 meter behind him.

Since GA are flying slower, I think that GA could do with less stringent latency requirements.

In both cases it is allowed for the transponder to compensate for some latency by extrapoling the GPS position using the GPS ground speed vector. There are limits to the amount of compensation allowed.

[ATCast]

The only thing I'd be interested in is whether or not there is a possibility of getting weather etc through the system...are we likely to see that in Europe any time soon? Isn't the FAA planning to provide this for free to aircraft with the right equipment to receive it?
From what I have understood there are no plans in Europe to provide weather. ADS-B on 1090 Mhz in not suitable to do that.

In the US they are deploying two separate systems, 1090Mhz for the big guys above 18000ft and UAT for the others. With UAT it is possible to upload weather.

[betterfromabove]

Worth adding with regard to Eurocontrol that their Airspace Infringement Initiative's report on FIS, which contains many solid suggestions, makes no explicit mention of ADS-B in its recommendations.

From what I can see, it assumes Mode S uptake will be limited in the European GA community (mainly Netherlands and Germany for country-specific reasons) and that full ADS-B will be prohibitively expensive or impossible for much of the c.120,000 GA fleet.

[achimha]

Under the existing EASA approvals for installing a Mode-S transponder providing elementary surveillance data, it is not permitted to radiate additional data elements such as position.

I keep reading this but have not managed to find any clear, official, binding statements.

My setup is a Filser/Funkwerk TRT800A transponder connected to an IFR certified GNS430W, configured to radiate extended squitter position data. The transponder comes with an EASA STC and its installation manual shows how to connect it to a GPS source and how to enable the extended squitter.

Installed and operated according to the STC. How could this be wrong? That's what the manufacturer says as well.

[peterh337]

I keep reading this but have not managed to find any clear, official, binding statements.

I wrote this (http://www.peter2000.co.uk/aviation/tb20-experience/mode-s.html) up in 2008 - may be a start for research.

There is NO evidence that anybody actually cares what you radiate, and of course any planes visiting the EU, with Mode-S, will prob99 be radiating the whole lot anyway :E

I am not a pilot myself, but I am involved in standardisation of ATM-technologies. The reason that I join the discussion here is to better understand GA point of view.

That seems a good idea. It's a pity however that people involved in this are not IFR pilots. It's no wonder we get so many stupid regs. What exactly is the point in worrying whether position data is 0.6 seconds old? Radar does a sweep only about every 5-10 seconds...

I am sure the PRNAV utter-bollox (forcing 5-figure avionics upgrades) comes from the same stable. Currently, 99% of GA is unaware this bombshell is coming to UK enroute airspace.

[gasax]

Like many of these technical discussions on here I find this immensely depressing. I have a permit aircraft and one of the few 'advantages' I could see in fitting a Mode S transponder is that I could radiate a GPS position and so gain some limited 'protection' form that.

And yet we see people involved in the formulation of policy and process arguing about issues like data latency and quoting speeds of 500kts - what about the speed restrictions below 10,000? - (apart from the military naturally!). At 500kts you are dependent upon ATC radar predicting it course and where the aircraft is going - not about where it might or might not happen to be at any precise instant (let alone Peter's comment about radar latency...).

These techy thype issues are always the points at which equipment or processes become gold plated and hence usually too specialised or expense to actually yield their potential benefits. The Us approach to ADS-B seems so much more enlightened it does raise questions over the intelligence of EASA and EU authorities. If you give pilots some benefits from fitting this equipment - such as in-flight weather - fitment rates will be high. Compare and contrast with the current Mode S mess where because there are NO benefits (apart from maybe the partial one I mention at beginning) fitment rates are very low outside of Germany and the Netherlands - where it was a fit or be grounded issue.

[Rod1]

“The certification usually covers Mode S, as described in (E)TSO-C112.
However in general it does not cover the ADS-B specifications (E)TSO-C166b.”

Could you give examples of EASA approved Mode S units which support ES and do not have approval for ADS-B?

The cost of emitting ADS-B out in hardware terms, if you have a suitable transponder and a GPS with a suitable interface is the cost of an RS232 cable and 5 min setting up the user configurations. It is defiantly not allowed to do this on a permit aircraft. The LAA has recently been in discussions with the CAA over it. Special permission can be gained for short term testing but that appears to be dependent on having a RAIM capable unit.
The advantage to GA of emiting ADS-B out with SIL = low is it would save lives!

Rod1

[peterh337]

one of the few 'advantages' I could see in fitting a Mode S transponder is that I could radiate a GPS position and so gain some limited 'protection' form that.Your best "protection" is to carry a Mode C (or Mode C/S) transponder and use it all the time. Then you will be visible to everything "turboprop and above" and quite a few well equipped piston planes, which all have conventional active TCAS (the sort you can install in GA for ~£15k). Despite official usage limitations in AOC ops, these active systems really do work. The only reason I don't have one is because the multiple antenna installation of an Avidyne 600 would mean a total strip-out of my cockpit and X weeks of downtime, where X starts when the last of the existing customers of the said avionics shop has finished screaming at them to finish his job :)

ADS-B is not used for TCAS purposes although it would be pretty good for it - like FLARM is which is basically ADS-B but non-ICAO ;)

I don't see any point in complying with any future ADS-B unless they are mandated. Can any FLARM product receive ADS-B? If it could, that would be a plus.

An even better protection is to have an autopilot and use it, linked to GPS. Then you have almost zero head-down time and can keep a lookout for all those nontransponding planes :E OTOH if you fly above 2000ft, you avoid 99% of them anyway ;) (seriously, there is a massive and very obvious correlation there).

The cost of emitting ADS-B out in hardware terms, if you have a suitable transponder and a GPS with a suitable interface is the cost of an RS232 cable and 5 min setting up the user configurations. It is defiantly not allowed to do this on a permit aircraft. The LAA has recently been in discussions with the CAA over it. Special permission can be gained for short term testing but that appears to be dependent on having a RAIM capable unit.This has to be bollox because most planes not subject to Eurocontrol/EASA regs (which has got to be about 90% of world's aviation) will be emitting all this stuff when in EU airspace...

A requirement for RAIM for ADS-B emission is IMHO a misunderstanding of how GPS works. There are loads of situations where you use a GPS enroute but you can't get a RAIM computation. RAIM is a calculation entirely based on satellite geometry and is nothing to do with the equipment actually installed. You can do a RAIM prediction on your PC at home, for a given route and time.

If a GPS is good enough for nav then it is good enough for radiating your position on extended squitter or ADS-B.

It is widely known that Eurocontrol is full of techno boffins who produce 10,000 page documents which nobody understands. A while ago I was speaking to the dep. head of EASA at some presentation and he moaned that Eurocontrol documents need a wheeled trolley to move about. For every 500 page doc his outfit produces (which almost nobody can read, and I am sure it is intentional - vis the current 2 year derogation scandal) Eurocontrol produce 10,000 pages (which nobody at all can read).

[Rod1]

“This has to be bollox”

Which bit, the RS232 or the fact that the CAA have told the LAA no? Or somthing else entirely:rolleyes:

Rod1

[Denti]

Can any FLARM product receive ADS-B?

Yup, Powerflarm for example can. And i'm sure there are others. Funkwerk offers a traffic monitor which primarily displays ADS-B info and has an interface to an external FLARM unit.

Many GA ADS-B installations send out a permanent NAC/NUC of 0 which means there is no integrity check (RAIM interface) and those positions will have to be disregarded by both traffic monitors and ATC. Current traffic monitor solutions might still display them without warning that the position may be wrong, which in itself is not a really safe solution.

DME/DME RNAV solutions can be BRNAV certified, we had that in our flight training aircraft (Cheyenne III) before we switched over to GPS, even certified for RNAV approaches down to RNP 0.5. FMS based DME/DME navigation was enough for PRNAV certification in our 737 3/500s and is enough to serve as PRNAV certified backup system in our NGs, except for RNP AR which requires switching off of VOR/VOR, VOR/DME and DME/DME updating.

Anyway, current (AMC 20-24) and future ADS-B regulation on installation in europe are aimed at commercial air traffic. There is not much for GA below 250kts cruise and less than 5,7t MTOW. That probably has to do with the amount of IFR traffic in those respective aircraft classes in europe as sadly GA IFR in SEP / light MEP is not really all that common.

[peterh337]

DME/DME RNAV solutions can be BRNAV certified, we had that in our flight training aircraft (Cheyenne III) before we switched over to GPSAs a matter of interest, what product did you have installed in there, and when was it?

traffic monitor solutions might still display them without warning that the position may be wrong, which in itself is not a really safe solution.Does it matter, given that these products (Kinetic, etc) are used seemingly mostly for plane spotting?

What (if any) real purpose does ATC use ADS-B for in Europe?

Last time I spoke to Eurocontrol at some show they said ADS-B data is not used for any ATC purpose. Only primary and SSR radar is allowed for position determination.

Yes IFR GA is very thin, but then so is any traffic between say FL100-200 enroute. Many times I have done a say 700nm leg and never saw anything remotely near. That lower airways airspace is virtually empty, outside the terminal areas.

[Denti]

Well, eurocontrol runs the cascade program which deals with ADS-B in europe. However ADS-B is not (yet) used for primary control functions as far as i'm aware.

I wasn't talking about ground based traffic monitors but about the flightdeck based systems available now. Stuff like SBS-1 or others like that are indeed just a tool for plain spotters or the airplane noise brigade.

[peterh337]

What product did you have installed in the Cheyenne, and when was it?

[Rod1]

“What (if any) real purpose does ATC use ADS-B for in Europe?”

It may be used on the North Sea rigs for the helicopters but I have no official conformation of that.

ADS-B could be very useful in collision avoidance, but I will know more in a month or so.;)

BR,
Rod1

[piperarcher]

Isn't ADS-B the only way to display collision avoidance data on a Garmin GNSx30 device, if you have something like the Garmin GTX330 transponder? I am sure thats how they use that functionality in the US.

When our old transponder died, and we installed a GTX330, I was really hoping we could see traffic data presented on the GNS430. We were told by the avionics engineer that we couldnt have the ADS-B enabled. Quite how he didnt enable it, I dont know, just that we dont have the traffic page available on the GNS430.

[peterh337]

To get traffic data, it has to be uploaded from ATC, and nobody in Europe has bought the extra software/equipment to do that. They all could (as they have in the USA) but they have decided to not spend the money.

So NO traffic data via Mode S in Europe, now, or ever.

As regards emitting ADS-B data, I don't know what exactly is involved but an obvious pre-requisite would be a GPS-transponder connection carrying the NMEA data. That is trivial, but "illegal".

I don't know what extra config there is in a GTX330. I have the Installation Manual and you can find it on the internet easily enough.

[Rod1]

“I don't know what exactly is involved but an obvious pre-requisite would be a GPS-transponder connection carrying the NMEA data.”

On a 330? Most 330’s are the standard model which needs an upgrade to the ES version at around £1000. Then you connect an RS232 cable running at 4800 or 9600 in most cases to get the data in. Almost all non-Garmin mode s units have ES as standard. On the Trig TT31 it takes seconds to set up and it displays the status of the I/F and the position data being received.

Rod1

[peterh337]

Interesting.... incidentally when one well known avionics shop was contracted to connect the KLN94 to the GTX330, and could not get it working, despite 2 visits, and both Garmin and Honeywell washing their hands of it despite the connection appearing explicitly in the GTX330 IM, I was looking into it and one could see some of the data from the KLN94 but not e.g. the GS, so there are possibly various inter-vendor compatibility issues, and these will never be fixed because nobody wants to fix old stuff when they can sell you new £10,000 boxes :)

I bet that if ADS-B became mandatory a lot more of that would surface - unless you have an all-Garmin stack.