End of ATSOCAS

[Lissart]

I understand that EASA will be mandating as of January 2020 that no Air Traffic Control service can be provided outside of CAS - i.e. class G. (There are 5 years to implement it apparently.) This will obviously mean the death of Deconfliction, Traffic and Procedural services as we know them, unless a UK type fudge can be found. I am struggling to find the exact references for this change. EU 373 Part ATS does not seem to give me the nuts and bolts of it. Anyone out there able to help with the specific references? (Apologies for having to ask, which I take as a personal failing on my part....)

[2 sheds]

The term ATSOCAS was changed some time ago in favour of FIS(s) in order to create the very fudge to which you refer - and we do not provide a control service outside CAS.

2 s

[Lissart]

2 Sheds,

Sorry - I'm not currently using them being in class D. So, does that mean that we will happily be able to still provide these services - which however you crumble the cookie are CONTROL - or not? That's what I need to know (with refs if possible.....) Someone in the CAA told me they'll be outlawed shortly.

??

[Gonzo]

No. We will not be able to provide vectors to any traffic outside CAS, unless for emergency avoiding action. So no DS, and no Approach Control Service (i.e. vectoring to an instrument/visual approach) as we know it today for Class G airports.

EASA view is that if an airport has ATC, it must have CAS.

The pragmatic (??) solution is to create lots of Class E.

ATS.TR.200:
ATS.TR.200 Application Air traffic control service shall be provided:
(a) to all IFR flights in airspace Classes A, B, C, D and E;
(b) to all VFR flights in airspace Classes B, C and D;
(c) to all special VFR flights;
(d) to all aerodrome traffic at controlled aerodromes.

CAA response from this doc:

https://www.easa.europa.eu/sites/default/files/dfu/CRD%202016-09%28B%29.pdf

CAA Comment: At present, the UK permits elements of an ATC service to be provided outside controlled airspace by air traffic controllers. Historically, the UK’s stance has been that the requirement for controlled airspace was required to be proven based on the nature of the operation and its associated risks. This stance was supported by the UK’s codification of ICAO FIS requirements through the development and application of ATS outside controlled airspace and the performance-based safety oversight by the competent authority.
Consequently, from the UK’s perspective, Part-ATS represents a paradigm-shift in ATS provision and the application of the airspace classification system. The UK CAA supports the principle that ATC service is provided by air traffic controllers within controlled airspace and aspires to move towards this position. However, implementation of these provisions represents a significant challenge – specifically in terms of our operations within uncontrolled airspace – which we believe will require considerable time to bring to a conclusion.
The UK CAA assesses that this implementation period will extend well beyond the traditional timescales applied by EASA and the Commission for transitional arrangements, given the need to address and mitigate structural, procedural and resource impacts. As such, the UK CAA seeks to engage further with the Agency and the Commission to determine how that transition can be safely managed. Justification: UK implementation of Part-ATS proposals concerning the provision of air traffic services in uncontrolled airspace represents a significant challenge which the UK CAA believes will require considerable State, Competent Authority and industry resource to bring to a conclusion. The impacts and potential ways forward cannot yet be definitively identified nor costed; however the cost impacts are currently considered to be considerable. Transition must be undertaken in a safe and efficient manner and cannot be undertaken in haste; hence the UK CAA's firm belief that an extended transition period is required in this regard.


EASA Response: Partially accepted. The ATS organisation in the UK and the challenges relevant to the implementation of Part-ATS are duly noted. EASA is prepared, during the transitional period, to allocate the necessary resources needed to support its implementation in the Member States. The intent is to organise various implementation workshops and, when necessary, bilateral consultation events. The proposed date for entry into force of the amendments to Regulation (EU) 2017/373 concerning Part-ATS is 27 January 2022. EASA also proposes a flexibility in the applicability date by proposing the possibility to derogate from the application or requirements concerning the provision of services in Class G airspace, up to 22 January 2025, under specified conditions.

More EASA
​​​​​​​The provision of ATC service within Class G airspace seems to be unusual in consideration of the variety of airspace Classes which are available in Regulation (EU) No 923/2012 (SERA) for the selection when deciding the appropriate service to be provided. Since the provision in ATS.TR.150(a) foresees that the competent authority could suspend the VFR operations in the vicinity of an aerodrome, that would mean that this possibility implicitly exists also for uncontrolled aerodromes.

...
​​​​​​​Vectoring in uncontrolled airspace should only allowed in adverse weather conditions, as stipulated in point (a)(3) of AMC1 ATS.TR.160(d)(3) as proposed with NPA 2016-09. Allowing vectoring in class G airspace would de facto transform that part of the class G airspace into controlled airspace.

​​​​​​​

[Lissart]

Gonzo,

My dear fellow, that is EXACTLY what I was after. Thanks. You may have gathered that I am running to catch up a bit on this and jumping onto a roundabout that has been spinning for a while is challenging. Your post and the links mention vectoring but do not specifically mention the usual Procedural Approach Control techniques to achieve separation, requiring a/c to fly specific tracks, levels, arcs etc. I take it though that the spirit of EASA's logic would apply equally to APP. This therefore will have as big a knock on effect for non-radar procedural units as those with surveillance. Take a scenario where an APP has a deemed separation stating that once an a/c has gone beacon outbound on a published instrument approach, a departure may climb straight ahead until above the arrivals level before turning on track. "Control"? Well, yes sort of but not quite in the sense of a controller "choosing" a vector depending on a/c position. EASA are doubtless not going to stop IFR a/c flying published approaches outside of CAS! (Are they.....?!!)

I agree that therefore a pragmatic approach might be class E. But to me that changes little for non-radar units. You still don't know that the "unknown" VFR traffic, who is not talking to you and does not require a clearance to enter the airspace, is out there! Now a "situation display" of a surveillance nature - with TMZ if needed by the technology in use - to give APP some idea that there is VFR traffic out there, when combined with class E - now that makes sense to me.

Thanks for the assistance. Further thoughts welcome.

LISSART

[chevvron]

Even if civilian controllers are prevented from providng ATSOCAs, the RAF will still have a 'need' to provide them as apart from Brize Norton and Northolt, they operate entirely in class G airspace. .

[possibleconsequences]

This is one hell of a change proposed and without a ‘fudge’ could severely effect many airports- how does somebody vector a sequence outside CAS for example?
So- reclassify all airspace so there’s hardly any class g left or expand every control zone so they’re all linked up ?

Any bright ideas on this?

Sorry- can’t find the relevant reference either!

[Lissart]

Does not Chevrron make an excellent point? PAR and all... Maybe they will fudge it with extended MATZ dumbbells or something. Or just call it "military imperative."

[Pringle_]

Sounds like an expensive exercise with little safety benefit to me. Creating swathes of Class E that are going to require ATCOs to provide a service at a time when there is a national shortage is surely not the best solution:ugh
Given that aircraft flying VFR in class E have no obligation to receive an ATC service, other than separating against other IFR aircraft which will likely be receiving a service anyway, why would vectoring in class E be any safer than class G?

[Gonzo]

This is one hell of a change proposed and without a ‘fudge’ could severely effect many airports- how does somebody vector a sequence outside CAS for example?


That's the point, EASA thinks that shouldn't be happening, and in the next 5 years or so it won't be (usual assumptions about the B-word and EASA apply). Quite a few airports also commented on the NPA, but EASA is standing firm. ATC = inside CAS. Outside CAS = FIS/AFIS (as in limited to radar-derived traffic information at the top end).

Anyone fancy doing a CAP1616 process for about 50 airfields?..........

[Lissart]

I have read through the first 400 pages of the 600-odd in the EASA link posted by Gonzo above. Actually, a lot of it was really interesting. Interesting also to note who responded from the UK - Humberside for example. Clearly EASA are committed to seeing this through. While I would instinctively support folk's rights to do what they like, where they like, if they are legally allowed to do so - I'd support the freedom principle if you like - surely that is all very well until people exercising those freedoms choose to fly through the instrument approach track for CAT into a class G airport at 1000' and 3 miles. Having worked procedurally at a radar unit I've seen some worrying moments. (Yes, I know what the ATM is supposed to be used for!!) Freedom to do what you want is one thing but sound airmanship is another. Can any GA pilot really complain about having to carry and operate a transponder to have access to a TMZ for example? If the same is contiguous with class E you can drive through it VFR without talking to anyone but the people who NEED to know you are there do! So you won't hit that airliner you didn't see.... What ever the statistics about mid-airs and airprox's surely nobody will argue too much with that argument. Procedural Approach in class G has never been (for me) about separation of known traffic - that was the easy bit. It is about what you didn't know. Although the rule book said that if you didn't know about the traffic then it was not your problem. Maybe we should ask the Italians. I was under the impression that ALL of their airspace is controlled.
As to the CAP 1616 process, if the CAA support the principle of CAS - which they say they do - and EASA are mandating it, then surely the process becomes rather more straight-forward!

[kcockayne]

I am with EASA. I have always thought that vectoring IFR traffic in Class G is dangerous - ever since I tried it at Coventry in 2007/8. ATCOS operating in busy Class G do a wonderful job, but they are risking their licences every time that they do it !

[Doody2007]

The following paragraph is taken from mats part 1, section 1, chap 1.

5.3 Air traffic control service shall be provided:
(1) to all IFR flights in airspace Classes A, B, C, D and E;
(2) to all VFR flights in airspace Classes B, C and D;
(3) to all special VFR flights;
(4) to all aerodrome traffic at controlled aerodromes

Doesn't this mean that we are all complying with the proposed EU legislation already?

Unless EASA are mandating that we abandon the UK flight information services, but I can't see any reference to that.

[chevvron]

I am with EASA. I have always thought that vectoring IFR traffic in Class G is dangerous - ever since I tried it at Coventry in 2007/8. ATCOS operating in busy Class G do a wonderful job, but they are risking their licences every time that they do it !
I did it at Lindholme in '73 (Northern Joint Radar Service Area) and at Farnborough from 1974 to 2008.
It's OK when you get used to it and the Area Radar course at the college included a few sessions on it.

[10 DME ARC]

I worked it for 18 years at Newcastle, when they only had a small class D zone, less towards the end when Newcastle was linked into the airways system. It is manageable especially now the military are significantly reduced. At times it can be difficult I remember giving a BA B752 three virtual orbits on its way to Pole hill trying to keep my 5nm from military fast jets. We used to have LHR controllers come up on FAM flights and say they couldn't do this!! Happy days....

[xtophe80]

Can any GA pilot really complain about having to carry and operate a transponder to have access to a TMZ for example?

As long as buying and installing a transponder cost between 20 and 25% of the value my aircraft, I will complain.

If the same is contiguous with class E you can drive through it VFR without talking to anyone but the people who NEED to know you are there do! So you won't hit that airliner you didn't see.... What ever the statistics about mid-airs and airprox's surely nobody will argue too much with that argument.

Pure class E works in plenty of places in the world. Why does UK ANSPs and UK CAA cannot trust the pilot to judge and maintain VMC?

[HershamBoys]

Because operating in UK Class D, a significant element of CAT aircrew, and many GA pilots, have little understanding of the responsibilities pertaining to the provision of ATS. Many CAT crews have an expectation that ATC will ensure that their flight does not encounter conflicting GA traffic, even if pertinant traffic traffic information has been passed to both aircraft, and they can see each other. If a TCAS alert is received, CAT crews have an obligation to respond. This automatically generates a Safety Report from both aircrew and ATS, resulting in a chain of events starting with the pulling of the controller for investigation, and potentially leading to Licence suspension. This has been discussed at great length on another British GA forum.
Some GA pilots operating VFR believe that it is acceptable to fly in close proximity with IFR traffic that they can see and avoid: fine for them, but almost inevitably the CAT crew will file a report. Again, this results in action under the SMS, and, if the number of reports increases, those running the SMS may turn to the ANSP manager and request the adoption of practices that stop the encounters happening.
The guidance being offered recently from the ATS regulatory side is that these conflicts should be prevented, meaing that ATC have to actively segregate or deconflict the aircraft involved.
The upshot of all this is that ANSPs, in order to satisfy the regulators and the local SMS, are likely to become very cautious when granting access to CAS of VFR traffic, and if it is allowed to enter, to proactively manage potential conflicts, using a level of intervention which is far more restrictive that permitting VFR pilots to 'see and avoid'. Access to CAS, and VFR operations within it, have been discussed at length on another British GA forum.
Another consideration that must be be understood is that the ATS system in the UK is not 'national'. ATS operations in many Class D zones, and at those airports hosting CAT which are located outside CAS, are supporting the business of the airport. If the SMS of an airline operating into one of these airports is recording a high number of incidents involving conflict or perceived conflict with GA VFR aircraft, it is likely that the airline's safety department will approach the airport operator for an explanation, or more probably, a resolution that stops their operations being impinged on by the VFR traffic. The business priorities of the Airport, its operator, and its shareholders, will come first. Transiting GA traffic, or the provision of ATSOCAS in adjacent Class G areas, will not generate any income, and will require staffing. If I am managing an airport in the UK, competing with an adjacent airport for high end traffic that pays the highest fees, service provision to aircraft that are not landing at or departing from my airport will not be my priority. I need to keep my paying customer satisfied, and if it means restricting the transit of GA aircraft through our airspace, or minimal service provision to aircraft flying adjacent to it, so be it. I can always use our SMS to claim that I am reducing risk.
There has been much discussion about ATS provision outside CAS, access to CAS, and ATS operations within CAS, on another GA forum. Many of the contributors call for a a level of service provision to the GA community that mirrors that of the USA, or one that offers a level of service that is far in advance of what is available now. What these posters should remember is that ATS outside the airways system in the UK has been privatised, fragmentised, and encouraged to adopt a business-based model. The result is a disconnected service that reflects on the business needs of the airport from which it is provided, and is provided on the basis of the local business requirements and resources. If the GA community believe that this can be replaced by some kind of national joined-up system funded by the taxpayer, they are in clooud cuckoo land.
Assuming the UK complies with the EASA requirements, there will seemingly be an expansion of CAS to accomodate the instrument procedures for those airports presently sitting in Class G. Where the associated controllers are going to come from, and how they will be funded, I cannot say. What I do forsee, however, is an increasing reulctance of ANSPs, for all the reasons I have expanded on above, to permit GA traffic the access to this new CAS on a see-and-avoid basis, and a reduction in ATSOCAS provision to aircraft operating outside CAS, further adding to the level of discontent felt by elements of the GA community.

[kcockayne]

A very comprehensive , informative & factual answer. Thank you.

[2 sheds]

As kc said, except...

If I am managing an airport in the UK, competing with an adjacent airport for high end traffic that pays the highest fees, service provision to aircraft that are not landing at or departing from my airport will not be my priority. I need to keep my paying customer satisfied, and if it means restricting the transit of GA aircraft through our airspace, or minimal service provision to aircraft flying adjacent to it, so be it. I can always use our SMS to claim that I am reducing risk.

...the concept of "our" airspace. It is airspace of a notified classification in which the procedures for the application of ATS are/should be consistent world-wide.

​​​​​​​2 s

[eagleflyer]

Controlled airspace doesn´t have to be Class A-D. For small airfields with few IFR movements Class E down to the ground allows IFR and doesn´t prevent VFR operations for no good reason.

[whowhenwhy]

Just bear in mind that this is not EASA's idea. All that EASA has done is to transpose what is left of ICAO Annexes 10 vol 2 and 5, Annex 11 and PANS-ATM into EU Regulations. For many decades, the UK has just been using a lot of complicated sentences to try to explain how we comply with ICAO SARPs and PANS. The fact is that we're not compliant and now it looks like we're going to be.

[jmmoric]

Since I've been working class D control zones with class E terminal areas, I can only say that it works really well.

You'd still get traffic information in the control zone, and the terminal area (if we're aware of any aircraft there communication/coordinated/transponder). And we'd keep the VFR away from the arrival paths of IFR flights (final/departure).

The problem with G airspace, is that VFR can fly just under the clouds, no transponder, no radio, giving the IFR guys comming in on a localiser a real hard time to spot him before it's too late. The D airspace relieves the IFR flight of that in a critical phase of his flight.

I do not think class E is good enough for a control zone though?

What otherwise can be done, is establishing a traffic information zone, where the class is G, but radiocommunication is required, and man them with aerodrome flight information service. That'll give better protection close to the field than no zone.

[chevvron]

Since I've been working class D control zones with class E terminal areas, I can only say that it works really well.

You'd still get traffic information in the control zone, and the terminal area (if we're aware of any aircraft there communication/coordinated/transponder). And we'd keep the VFR away from the arrival paths of IFR flights (final/departure).

The problem with G airspace, is that VFR can fly just under the clouds, no transponder, no radio, giving the IFR guys comming in on a localiser a real hard time to spot him before it's too late. The D airspace relieves the IFR flight of that in a critical phase of his flight.

I do not think class E is good enough for a control zone though?

What otherwise can be done, is establishing a traffic information zone, where the class is G, but radiocommunication is required, and man them with aerodrome flight information service. That'll give better protection close to the field than no zone.
How can you 'keep the VFR away from the arrival path of IFR flights' when it's not talking to you and it doesn't need to talk to you? In that scenario there's no difference between Class E and Class G.

[Talkdownman]

How can you 'keep the VFR away from the arrival path of IFR flights' when it's not talking to you and it doesn't need to talk to you? In that scenario there's no difference between Class E and Class G.
Bournemouth ATC has recently chewed off some poor bloke VFR in a Mooney (https://www.airproxboard.org.uk/uploadedFiles/Content/Standard_content/Airprox_report_files/2019/Airprox%20Report%202019036.pdf) for having the temerity to remain outside CAS. One simply cannot win, Bournemouth seem to want it both ways :rolleyes:

[jmmoric]

How can you 'keep the VFR away from the arrival path of IFR flights' when it's not talking to you and it doesn't need to talk to you? In that scenario there's no difference between Class E and Class G.

You're right about that, and sorry for the slight mistake I made in the text.

The control zone AND the terminal area are class D, that is the lowest classification we use for control zones and terminal areas. We do have a control area above, and THAT is class E (which is above 6500') So you're right, when up there, everything between VFR and IFR befalls the pilots. But lower when the turning and separations inbound/outbound begin, we WILL be in contact and to the required extend control VFR flights as well.

Once you get above 3000' AGL VFR you'd have to have a larger margin between you and the clouds, and also speed depending, and above FL100 even higher margins.. All in all to avoid IFR/VFR bumping into each other at the egde of clouds. And we make sure it doesn't happen in the TMA/CTR of course.

Having an airspace like that is not that big of an restriction as people might think, for the most part pilots get what they want, and for VFR instruction to "remain below/above xxxxFT", "remain east/west of xxxx" usually solves it, and still give the pilot a lot of room to manouvre. And airspaces should in general be constructed so the airspace is as close to the minimum required. But you know that :)

[jmmoric]

Bournemouth ATC has recently chewed off some poor bloke VFR in a Mooney (https://www.airproxboard.org.uk/uploadedFiles/Content/Standard_content/Airprox_report_files/2019/Airprox%20Report%202019036.pdf) for having the temerity to remain outside CAS. One simply cannot win, Bournemouth seem to want it both ways :rolleyes:

There's no mentioning that ATC tried to put the blame on the Mooney pilot, there's no mentioning ATC put a blame on the Falcon crew, just that ATC did what they were supposed to do in class G.

And there's no "chewed off" here?

We are here for you guys, not the other way around. It's all about working together to get a safe and effective flow of traffic, and make room for all, even the odd VFR pilot jumping around the countryside for fun (me too) :)

[chevvron]

There's no mentioning that ATC tried to put the blame on the Mooney pilot, there's no mentioning ATC put a blame on the Falcon crew, just that ATC did what they were supposed to do in class G.

And there's no "chewed off" here?

We are here for you guys, not the other way around. It's all about working together to get a safe and effective flow of traffic, and make room for all, even the odd VFR pilot jumping around the countryside for fun (me too) :)
The Falcon was receiving TS. Was a 'contract' agreed to provide TS? If it was a foreign pilot, did he even know what TS is?
At Farnborough in such a situation, we would offer a temporary upgrade to DS and I hope most other controllers would do so under 'duty of care'.

[Talkdownman]

There's no mentioning that ATC tried to put the blame on the Mooney pilot
I must have imagined reading this then:

Bournemouth Full Investigation report

The investigation concluded the following:

Causal Factor

• The pilot of [the Mooney] did not monitor the Bournemouth radar frequency despite flying in close proximity to the Solent CTA (class D airspace designated to the Bournemouth). The controller was unable therefore to provide the pilot with the traffic information which would have prevented the AIRPROX occurring.

[jmmoric]

The Falcon was receiving TS. Was a 'contract' agreed to provide TS? If it was a foreign pilot, did he even know what TS is?
At Farnborough in such a situation, we would offer a temporary upgrade to DS and I hope most other controllers would do so under 'duty of care'.

I have to admit, I have no clue how flying in the UK works, if I was to go there, I would read the AIP and relevant documents first? Do you establish a "contract" before providing traffic information based on RADAR?

[jmmoric]

I must have imagined reading this then:

Okay, I'd give you that.

Bournemouth thought 10 NM final could be considered final approach. The board didn't think so. Case closed :)

[Glamdring]

Be interesting to see how this affects the offshore heli operation.

[chevvron]

Do you establish a "contract" before providing traffic information based on RADAR?
When operating in Class G, yes.
Traffic service (TS) provides the pilot with information on possible conflictions.
De-confliction service (DS; available only to IFR traffic) provides the above plus advisory avoiding action.
CAP 1434 is the document to look at.

[Talkdownman]

Whilst I generally believe that the UK way, when it differs from ICAO and/or the rest of the world, does things well, the fudges on controlled airspace (and particularly doing control, whatever it might be called in uncontrolled airspace) and calling ATC functions FIS are an abomination which cause confusion and have been causal factors in a good number of incidents.
Referring to FIS and / or AGCS as "ATC" has similarly caused confusion, and has 'been causal factors in a good number of incidents'. The sooner we stop referring to air traffic control within uncontrolled airspace, the better, in my view...

[Talkdownman]

there has been a blurring in many people's minds - some at very senior levels in the CAA
Totally agree.
if you, the pilot, want to get down to an airport in poor weather, you need an instrument flight procedure. If you, the pilot want to be separated from or told about other traffic, you need ATC. If you want to approach in poor weather without having to worry about whether another aircraft will come at you out of the murk, you need both.
The next MAC during an IAP in IMC in Class G should change all that. The Big Sky Theory cannot go on forever...

[chevvron]

Whilst I generally believe that the UK way, when it differs from ICAO and/or the rest of the world, does things well, the fudges on controlled airspace (and particularly doing control, whatever it might be called in uncontrolled airspace) and calling ATC functions FIS are an abomination which cause confusion and have been causal factors in a good number of incidents.
See ICAO Doc 4444 para 8.11 'The Use of Radar in the Flight Information Service.'
That's the way, in my opinion, we should be doing it and I'm told is how France and Gerrnany do it.

[whowhenwhy]

Chevvron is, as usual, quite correct. Thankfully, from what I've heard, things are starting to move in the right direction in the CAA

[Lissart]

See ICAO Doc 4444 para 8.11 'The Use of Radar in the Flight Information Service.'
That's the way, in my opinion, we should be doing it and I'm told is how France and Gerrnany do it.

Yes but...... 4444 says: "The information presented on a situation display MAY be used to provide IDENTIFIED a/c with......etc." (My bold.) So before you can do anything really useful the a/c needs to be talking to you or, at best, someone else who has identified, validated and verified it. Right? Otherwise there is limited value in seeing that something is out there on your screen....

[Lissart]

The report on the Falcon/Mooney airprox has some interesting elements. I have often stated that the ability to give accurate, succinct and pertinent traffic information is one of the "arts" of this job. As by definition the circumstances are always different, it is not as easy as it may seem sometimes, especially in the heat of the moment when there might be a lot going on. One little slip, one little word slightly out of place and you could be in trouble. With that remark in mind - which is based on operational experience - one has to wonder at the comments from the Board: "the controller could therefore more accurately have described the Mooney as ‘converging’ rather than crossing, thereby further assisting the Falcon pilot to make a decision to give way. Additionally, the controller’s blind call to the Mooney pilot, that traffic in the left 10 o’clock would cross ahead left to right, may have helped to form an incorrect mindset in the Falcon pilot that he was ‘ahead’ and that he did not need to give way to the Mooney, " Seems to me the ATCO did a decent job and are we really to expect more? Easy to sit and pontificate on it in the cold light of day.....
Where I work we had a TCAS RA sometime ago where a big causal factor was less than optimum traffic info. Indeed, the controller pointed the pilots to the wrong place by using "left to right" - which it was slightly - rather than a more apt "head to head". But what about the perceptions? There must be a difference in human perception from a bloke behind a radar (there might be a "lag") to the pilot looking out of his bug-smeared window. A fine art and a delicate skill - easy to get just that bit wrong and create those false impressions.
As to giving way in the "final stages of approach", well please! Would it not be helpful if that was defined? I bet many pilots would have trouble considering that in those circumstances. (I believe Lydd had something similar recently with inst app traffic not giving way on "final" and they are operating procedurally!!)

[chevvron]

Yes but...... 4444 says: "The information presented on a situation display MAY be used to provide IDENTIFIED a/c with......etc." (My bold.) So before you can do anything really useful the a/c needs to be talking to you or, at best, someone else who has identified, validated and verified it. Right? Otherwise there is limited value in seeing that something is out there on your screen....
I don't get your point; controllers in France (so I'm told) routinely identify aircraft who call them requesting Flight Information Service; once identified the height readout MUST be verified and thereafter, traffic information and (when necessary) advisory avoiding action is passed.
In the UK, controllers MUST identify and verify altitude readout for traffic requesting TS or DS unless the identity is transferred from another radar unit who will have already done this. Traffic requesting Basic service ie what used to be called Flight Information Service MAY be identified and if so, any altitude readout associated with their SSR must be verified. Thereafter even this traffic may be passed generic information on possible conflicting traffic especially when 'duty of care' requires it ie if you see a 'dead ringer' for your traffic you should tell the pilot about it rather than sit there and do nothing.
In the case quoted at Bournemouth, even though the Falcon was only on Traffic Service in the Initial Approach phase, NOT the Final Approach stage, he was identified so the controller could have offered advisory avoiding action (traffic is in your ......, if not sighted suggest left/right heading...) or if the confliction looked serious, upgraded the Falcon to De-confliction service and passed avoiding action prior to passing the traffic information.

[chevvron]

Chevvron is, as usual, quite correct. Thankfully, from what I've heard, things are starting to move in the right direction in the CAA
Thanks mate.
I only provided radar based services in Class G and its predecessor for a total of 35 years, 34 of those being at Farnborough, traffic handled ranging from microlights up to Tornados amd Lightnings but the CAA didn't seem to want to know when I suggested we use ICAO procedures at a 'workshop' at Kingsway during the review of 2007/8 resulting in the present procedures which commenced in 2009, just after I retired.
In other fields, eg millibars to hectopascals, the CAA seemed only too keen to comply.

[chevvron]

London Info and Scotthish Info still operate but they're manned by ATC assistants with an Area FISO Licence hence they are unable to provide a radar service although I understand the Scottish FISOs only do day duties and hand over to one of the main Scottish sector controllers at night..
(Now someone will come along and say 'FISOs in my country can provide a radar service'):rolleyes:

[jmmoric]

London Info and Scotthish Info still operate but they're manned by ATC assistants with an Area FISO Licence hence they are unable to provide a radar service although I understand the Scottish FISOs only do day duties and hand over to one of the main Scottish sector controllers at night..
(Now someone will come along and say 'FISOs in my country can provide a radar service'):rolleyes:

FISO in Denmark provide radar service, call them, you get a squawk, get identified and traffic info on other traffic in the area, also on traffic they have not directly identified, but can see :)

[Lissart]

I don't get your point; controllers in France (so I'm told) routinely identify aircraft who call them requesting Flight Information Service; once identified the height readout MUST be verified and thereafter, traffic information and (when necessary) advisory avoiding action is passed.
In the UK, controllers MUST identify and verify altitude readout for traffic requesting TS or DS unless the identity is transferred from another radar unit who will have already done this. Traffic requesting Basic service ie what used to be called Flight Information Service MAY be identified and if so, any altitude readout associated with their SSR must be verified. Thereafter even this traffic may be passed generic information on possible conflicting traffic especially when 'duty of care' requires it ie if you see a 'dead ringer' for your traffic you should tell the pilot about it rather than sit there and do nothing.
In the case quoted at Bournemouth, even though the Falcon was only on Traffic Service in the Initial Approach phase, NOT the Final Approach stage, he was identified so the controller could have offered advisory avoiding action (traffic is in your ......, if not sighted suggest left/right heading...) or if the confliction looked serious, upgraded the Falcon to De-confliction service and passed avoiding action prior to passing the traffic information.

Chevron, my point is simple and has nothing to do with the a/c you ARE talking to - which as you say is validated, verified etc. - but the ones that you are NOT talking to. How can you give SENSIBLE Deconfliction and/or Traffic information to the one you are talking to, against the one that you are not? Now, I know that you can obviously but it gets messy with words such as "indicating" and "altitude unverified" etc being used. In the Bournemouth incident the controller did not know for sure what level the Mooney was at. He had to make assumptions. (One I heard at work recently while the radar ATCO validated and verified was 1000 feet lower than the pilot reported as he checked in! A pretty clueless piece of airmanship from the pilot to call at 1800' when he was at 800'. Altimeter incorrectly set !!!) To get the job done properly you need to either be talking to everyone, to be confident that you can see on radar (or know about if procedural) all the traffic that is out there and/or be sure that they are where they say they are both horizontally and vertically. Right? So, what is really the point of EASA class E as far as Air traffic Control services are concerned, when VFR don't need to talk to you, don't need to have a functioning transponder and can do what they like? Surely this is identical to the current situation with ATSOCAS in class G? Now, if you add a TMZ to the class E at least you have another layer of security.

[chevvron]

Simple. If your unknown confliction is showing a '7000' squawk (indicating a/c not receiving radar service) and no altitude readout you vector your own traffic at least 5nm away from it to allow for an unpredictable turn by the unknown.
If it's showing an altitude readout then irrespective of what is set on the aircraft's altimeter which will always transmit an altitude based on 1013.2 hPa, if the altitude indicated on the radar display (which will have the current QNH dialled in to enable it to convert from 1013.2) is showing 3,000ft above or below your traffic then traffic information is sufficient; if it's less than 3,000ft then the above applies.
I've never worked in Class E airspace, only Class G but I would imagine you would take the above action in airspace of either classification.

[Not Long Now]

I think, as will soon be the case with the new class E for the LF ACP, you are only obliged to pass traffic to the IFR you are providing a radar control service to, you do not vector to avoid.... Interesting theoretical cases to be discussed by lawyers et al....

[Lissart]

Simple. If your unknown confliction is showing a '7000' squawk (indicating a/c not receiving radar service) and no altitude readout you vector your own traffic at least 5nm away from it to allow for an unpredictable turn by the unknown.
If it's showing an altitude readout then irrespective of what is set on the aircraft's altimeter which will always transmit an altitude based on 1013.2 hPa, if the altitude indicated on the radar display (which will have the current QNH dialled in to enable it to convert from 1013.2) is showing 3,000ft above or below your traffic then traffic information is sufficient; if it's less than 3,000ft then the above applies.
I've never worked in Class E airspace, only Class G but I would imagine you would take the above action in airspace of either classification.

Chevvy,

Precisely! So there is not a gnats privates difference between class E - as proposed by EASA - and what actually and currently happens under a Deconfliction Service at the moment in UK class G!! On reflection therefore, one could argue that a potential widespread adoption of E by airports currently operating under G will change little for the end user.

[Lissart]

I think, as will soon be the case with the new class E for the LF ACP, you are only obliged to pass traffic to the IFR you are providing a radar control service to, you do not vector to avoid.... Interesting theoretical cases to be discussed by lawyers et al....

Blimey! So you were vectoring to Deconflict under DS in class G and now all you do is pass traffic! Is this progress...?

[Not Long Now]

No, was providing basic service in class G, now will be providing traffic info, if workload permits, and separation, ion appropriate, in controlled airspace. A great leap forward apparently.

[crossonagreen]

Lissart, You requested a definition of ‘Final Approach’. Annex 11

Final approach That part of an instrument approach procedure which commences at the specified final approach fix or point, or where such a fix or point is not specified:
(1) at the end of the last procedure turn, base turn, or inbound turn of a racetrack procedure, if specified, or
(2) at the point of interception of the last track specified in the approach procedure; and ends at a point in the vicinity of an aerodrome from which:
(a) a landing can be made; or
(b) a missed approach procedure is initiated. (ICAO Annex 11)

[jmmoric]

Blimey! So you were vectoring to Deconflict under DS in class G and now all you do is pass traffic! Is this progress...?

No, that is still not the case.

There's still the:

"Issue such ATC clearances as are necessary to prevent collisions and to expedite and maintain an orderly flow of air traffic."

So if you can see traffic, or have known traffic, you still have to make sure they do not collide. Like Chevvron says, 5 nm should be good enough.

You could argue that the required vertical/lateral separation minima does not apply, and you can go a bit closer, depending on the situation. But you'll still be held responsible if you let two known aircraft collide without acting.... Class E airspace will allow you to turn an IFR flight in this case.

[jmmoric]

Lissart, You requested a definition of ‘Final Approach’. Annex 11

Final approach That part of an instrument approach procedure which commences at the specified final approach fix or point, or where such a fix or point is not specified:
(1) at the end of the last procedure turn, base turn, or inbound turn of a racetrack procedure, if specified, or
(2) at the point of interception of the last track specified in the approach procedure; and ends at a point in the vicinity of an aerodrome from which:
(a) a landing can be made; or
(b) a missed approach procedure is initiated. (ICAO Annex 11)

Agree, and the ILS approach for RWY08 seems to have a FAF at 4.4 DME, so until then the Falcon wouldn't be on final approach... I suppose

[chevvron]

No, that is still not the case.

There's still the:

"Issue such ATC clearances as are necessary to prevent collisions and to expedite and maintain an orderly flow of air traffic."

So if you can see traffic, or have known traffic, you still have to make sure they do not collide. Like Chevvron says, 5 nm should be good enough.

You could argue that the required vertical/lateral separation minima does not apply, and you can go a bit closer, depending on the situation. But you'll still be held responsible if you let two known aircraft collide without acting.... Class E airspace will allow you to turn an IFR flight in this case.
5nm is the ICAO recommended minima; can be reduced to 3nm if both aircraft are identified and working the same radar unit.
In class A airspace the vertical separation minima against unknowns in the UK is 5,000ft, but that's not important right now.

[Lissart]

OK - perhaps it is time to re-focus the thread. Really useful contributions all round - thanks to one and all. It is always useful to revise a definition, or remind oneself of stuff one may not use every day. Not to mention benefitting from other people wisdom and experiences.

However, the thread is about ATSOCAS and their impending demise. There are 2 broad categories of airport who will be impacted by these changes as they currently provide ATC services in class G: those with radar and those without (procedural.) If we further confine our discussions to airports that have some or significant CAT flights, we are all agreed that the number 1 priority must be protection of these flights. In the first category we have for example, Exeter, Durham, Norwich, Newquay etc. In the second, Scilly, HIAL etc and others that may have radar but downgrade to APP during shoulder hours when a dedicated radar ATCO is unavailable. If you were responsible for the future airspace classification of these two types of airport, or were asked to comment as to how these businesses could respond to the possible threats that EASA changes pose to their operations, what would you be advising? Given that the CAA does not readily grant class D and this seems to be based on parameters such as passenger numbers (?) some if not all of these airports are not going to get D. (I believe - and I haven't checked due time - that the recent ACP for Exeter's class D was rejected...?) (Perhaps I have therefore answered my own question; the only solution left to them is class E!!!)

What are people's views on airspace classification changes and what service do you envisage being provided?

[chevvron]

OK - perhaps it is time to re-focus the thread. Really useful contributions all round - thanks to one and all. It is always useful to revise a definition, or remind oneself of stuff one may not use every day. Not to mention benefitting from other people wisdom and experiences.

However, the thread is about ATSOCAS and their impending demise. There are 2 broad categories of airport who will be impacted by these changes as they currently provide ATC services in class G: those with radar and those without (procedural.) If we further confine our discussions to airports that have some or significant CAT flights, we are all agreed that the number 1 priority must be protection of these flights. In the first category we have for example, Exeter, Durham, Norwich, Newquay etc. In the second, Scilly, HIAL etc and others that may have radar but downgrade to APP during shoulder hours when a dedicated radar ATCO is unavailable. If you were responsible for the future airspace classification of these two types of airport, or were asked to comment as to how these businesses could respond to the possible threats that EASA changes pose to their operations, what would you be advising? Given that the CAA does not readily grant class D and this seems to be based on parameters such as passenger numbers (?) some if not all of these airports are not going to get D. (I believe - and I haven't checked due time - that the recent ACP for Exeter's class D was rejected...?) (Perhaps I have therefore answered my own question; the only solution left to them is class E!!!)

What are people's views on airspace classification changes and what service do you envisage being provided?
Go back to one of my 'old' proposals.
For all airfields in Class G airspace with an approved iap, whether or not they have radar, civil or military, give them an ATZ of 5 nm radius up to 3,000ft agl. Present ATZ transit rules to apply.
This also gets rid of the stupid anomoly whereby a MATZ only applies to military aircraft.

[Gonzo]

Not sure that would work, as those airfields will have to downgrade to FIS only, if remaining in Class G.

The options are basically either downgrade to FIS and therefore all traffic has to self position to airports in Class G, or if vectoring/sequencing is required, establish CAS.

[Lissart]

Not sure that would work, as those airfields will have to downgrade to FIS only, if remaining in Class G.

The options are basically either downgrade to FIS and therefore all traffic has to self position to airports in Class G, or if vectoring/sequencing is required, establish CAS.


Yep, spot on those are the only choices. But just to clarify what you said: "if vectoring/sequencing is required" - or ANY other approach service which includes Procedural Control. There is no reason why APP cannot be provided inside CAS. Indeed, to my mind it makes more sense than doing it outside CAS IF (and only if...) there is a known traffic environment. This of course is a re-hash of the old argument as to whether providing an Approach service without surveillance equipment and only to KNOWN - or participating - aircraft is "safe". Or safe enough. The CAA by allowing APP in uncontrolled airspace believe that it is. I know of several instances where airlines carrying out their own risk assessments have concluded that it is not and have insisted on a radar service when operating in class G. So for both categories of airports - radar and non-radar - they will have to pay a lot of money to establish CAS or risk airlines getting pretty touchy about "only" being provided with a FIS. Given the reluctance of the regulator to sanction class D then this CAS they could establish will have to be E. The radar units can then carry on doing exactly what they are currently doing but pleasing EASA by calling it an ATC Control service. Ditto the procedural units but one might add that they might have missed an opportunity to have a more "known" traffic environment. If the class E route is taken, call it what you will but I see very little real change to the reality of the services currently being provided by what the UK chooses to call ATSOCAS. What am I missing - where is the real difference? Big winners? The consultancy firms carrying out the ACP's...…….

[chevvron]

Not sure that would work, as those airfields will have to downgrade to FIS only, if remaining in Class G.

The options are basically either downgrade to FIS and therefore all traffic has to self position to airports in Class G, or if vectoring/sequencing is required, establish CAS.
Has anyone told the BGA?
They've made a lot of fuss about Farnborough's proposed CAS and are making a lot of fuss about Finningley's CAS too, so not only Farnborugh will require the airspace but Odiham too.

[Pringle_]

Simple. If your unknown confliction is showing a '7000' squawk (indicating a/c not receiving radar service) and no altitude readout you vector your own traffic at least 5nm away from it to allow for an unpredictable turn by the unknown.
If it's showing an altitude readout then irrespective of what is set on the aircraft's altimeter which will always transmit an altitude based on 1013.2 hPa, if the altitude indicated on the radar display (which will have the current QNH dialled in to enable it to convert from 1013.2) is showing 3,000ft above or below your traffic then traffic information is sufficient; if it's less than 3,000ft then the above applies.
I've never worked in Class E airspace, only Class G but I would imagine you would take the above action in airspace of either classification.

This would be the case if the aircraft was under a deconfliction service, in the Bournemouth case the Falcon was receiving a traffic service and self positioning for the approach. The ATCO fulfilled their responsibility by passing traffic information and updating it as required. If the crew want deconfliction advice it is upto them to ask for it.

[chevvron]

This would be the case if the aircraft was under a deconfliction service, in the Bournemouth case the Falcon was receiving a traffic service and self positioning for the approach. The ATCO fulfilled their responsibility by passing traffic information and updating it as required. If the crew want deconfliction advice it is upto them to ask for it.
It is not just up to the crew to ask for de-confliction advice; if you read my #41 above, you will see what the controller could have done under 'duty of care' to resolve the confliction rather than just sit there and watch it happen.

[jmmoric]

It is not just up to the crew to ask for de-confliction advice; if you read my #41 above, you will see what the controller could have done under 'duty of care' to resolve the confliction rather than just sit there and watch it happen.

Agreed, noone is gonna come and pad you on the back, saying "good job", if there are 2 aircraft missing....

[Pringle_]

Respectfully I disagree, it is upto the flight crew to decide the appropriate level of FIS. By giving deconfliction vectors to an aircraft under a traffic service or providing routine traffic information while under a basic all you are doing is blurring the lines of what the pilot can expect from the type of service being provided. By all means if the crew request deconfliction advice or are under vectors for an approach then the ATCO is obliged to assist. The 'duty of care' is fulfilled by passing accurate and timely traffic information to the crew and updating it as necessary. CAP 774 is very clear about the responsibilities of all involved.

[chevvron]

Respectfully I disagree, it is upto the flight crew to decide the appropriate level of FIS. By giving deconfliction vectors to an aircraft under a traffic service or providing routine traffic information while under a basic all you are doing is blurring the lines of what the pilot can expect from the type of service being provided. By all means if the crew request deconfliction advice or are under vectors for an approach then the ATCO is obliged to assist. The 'duty of care' is fulfilled by passing accurate and timely traffic information to the crew and updating it as necessary. CAP 774 is very clear about the responsibilities of all involved.
So you're saying the controller should just keep passing traffic info until they collide?
At the inquest when the coroner asks 'why didn't you pass avoiding action?' I suppose you'll just say 'CAP 774 says I needn't'.

[possibleconsequences]

So you're saying the controller should just keep passing traffic info until they collide?
At the inquest when the coroner asks 'why didn't you pass avoiding action?' I suppose you'll just say 'CAP 774 says I needn't'.

When RAS/RIS changed to TS/DS it was to 'reset' the rules so that everyone knew exactly what level of service and what their responsibilities were (amongst other reasons). All well and good, all defined within tight boundaries then all muddled by saying 'oh by the way you have a duty of care'. Duty of care being a grey area. So as a controller i might decide that two miles head on similar level will make me upgrade to DS from TS but my colleague may decide that 3 miles 500' apart will trigger the change. Difficult to see how you can criticize one controller in one airprox if you define rules then muddle them up

[jmmoric]

I think we’re making the subject way harder than it should be.
We are all aware of our responsibilities, both when we’re flying or sitting on “the other end”. There’s no discussion that the PIC has the final word in controlling his aircraft, and there’s noone challenging that he is responsible for looking out and avoiding other traffic.
Noone is saying you can jail an ATCO for doing his best, even in uncontrolled airspace, when he is following the rules.
So as I said earlier, they won’t pad you and say “good job”, if someone collided when you only provided traffic info, they’d probably say you could have done more..... but it was within the rules and you’re not to blame.
But that’s how every report will be.... what could every participant, pilots, controllers, birds, bees and whatnot.. have done to prevent it.

[Lissart]

The quote that follows is from SRG after they investigated an airprox I am aware of. (It might not be word for word but that changes nothing in its' essentials.) Traffic was passed on a/c VFR, the other under radar vectors IFR, class D. TCAS saved the day when nobody flying the planes got visual with anyone else. "The controller did exactly what the book says he should do. But we don't want them doing it like that...…" There, Gentlemen, is the problem.

[whowhenwhy]

Jmmoric, the problem is that so many flight crew don't understand their responsibilities in class G airspace, let alone if you add the UK FIS into the mix. Too many pilots fly their aircraft as "good weather" or "bad weather" rather than VFR or IFR and I've heard ATCOs use IMC and IFR as interchangeable terms.

Under ICAO FIS, in uncontrolled airspace, if you have surveillance and the flight is identified, regardless of whether the flight is VFR or IFR, you provide traffic information and avoiding action if the pilot requests it or if you as an ATCO believe it necessary. If you want to provide ATC service, then you do so in controlled airspace but bear in mind that you provide FIS and alerting service alongside ATC service to controlled flights.

Change is coming. Give it a few months and we should here more.

[jmmoric]

whowhenwhy,
And the understanding that a visual approach is the same as flying VFR... I've heard that one a thousand times.

But you're right.

For the using of wrong phraseology for ATCO's, that could be a good subject for the yearly refresher training in the unit. The pilots? They're a lost cause....

[chevvron]

Under ICAO FIS, in uncontrolled airspace, if you have surveillance and the flight is identified, regardless of whether the flight is VFR or IFR, you provide traffic information and avoiding action if the pilot requests it or if you as an ATCO believe it necessary. If you want to provide ATC service, then you do so in controlled airspace but bear in mind that you provide FIS and alerting service alongside ATC service to controlled flights.

And that, in my opinion, is the way we should be doing it. I suggested it at the working group which decided the present services and was ignored; didn't even appear in the circulated meeting notes.
Actually when I first started (1973 as a cadet, 1974 as a controller) we had almost the same system:-
IMC Radar Advisory Service; the controller provides traffic information followed by avoiding action to maintain at least 5 nm from unknown traffic.
VMC Radar Advisory Service; the controller initially provides traffic information then avoiding action either at the request of the pilot or if the controller deems it necessary.
Flight Information Service using radar derived information; the controller provides traffic information to identified aircraft.
Flight Information Service; the controller passes proximity hazard warnings on known traffic; used for unidentified traffic or at units without radar.
All nice and easy until the late '70s when some d1ckhead decided to change it and that's when the rot started.
If anyone wants to know the next stage, I'm prepared to present it here but I don't want to go rambling on unnecessarily and boring you to death.

[chevvron]

The quote that follows is from SRG after they investigated an airprox I am aware of. (It might not be word for word but that changes nothing in its' essentials.) Traffic was passed on a/c VFR, the other under radar vectors IFR, class D. TCAS saved the day when nobody flying the planes got visual with anyone else. "The controller did exactly what the book says he should do. But we don't want them doing it like that...…" There, Gentlemen, is the problem.
MATS Part 1 Section 1 Chapter 1 para 1.2
'

[whowhenwhy]

Chevvron, prepare for some rot reversal 😊

[chevvron]

Chevvron, prepare for some rot reversal 😊
I'll believe that when it happens.

[Hallucinogenix]

Anyone heard any update to implementation of EU373, either from the CAA or any ANSPs? It seems deathly quiet out there in its Jan 2020 already!

[AAK10]

The only thing to surface appears to be the Fatigue Management part which is in effect a cut and paste from 670!

[Mister Geezer]

As someone who was on the receiving end of ATSOCAS many times during my early regional flying days, I can now unequivocally state, that the current array of services is the most complex state variance with ATC procedures that I have seen anywhere else in the world. The standard of controlling throughout the UK has always been meritorious in nature but service provision outside of CAS, is a confusing affair for many with no, or limited exposure to ATSOCAS in the UK.

Whilst responsibility for the pilot being aware of the different levels of service provision with ATSOCAS, is irrefutable, the practicalities of always achieving that may be challenging. Take the Air Ambulance pilot who is called out at short notice standby to fly from abroad and into a UK airfield in Class G. There needs to be an advance awareness that part of this flight will take place outside of CAS in the first place. Secondly, that pilot would need to be aware of the different levels of service that exist in ATSOCAS. Thirdly, they would need to have the time and the information to hand to ensure that there was familiarity with ATSOCAS in the UK, prior to being asked 'What service do you require'?

I now rarely need to use ATSOCAS but on a couple of occasions in the last few years that I have had to, my co-pilots on both occasions (who were not from the UK but still very experienced) were at a loss as to the different levels of service available in ATSOCAS. One of the exciting things about aviation is that the pace of change in technology advancement, has transformed how we do our job but it would seem that there is perhaps room for some transformation with how ATC is implemented in current Class G airspace in the UK.

[ShyTorque]

Maybe we ought to simply revert to the previous system and terminology. There was little to say against that.

[chevvron]

Maybe we ought to simply revert to the previous system and terminology. There was little to say against that.
See #71 above.
I think the problem with the previous system was that at some units 'FIS' traffic was identified, becoming 'known traffic' and hence passed 'generic traffic info' but at others they weren't, making them total unknowns and the passing of traffic info 'blurred' the border between FIS and RIS; introduction of Basic and TS was supposed to stop this but obviously hasn't as at some places, traffic requesting basic still needs to be identified to produce a 'known traffic' environment.
Years ago we did try doing this at Farnborough ie not identifying traffic requesting FIS but had to abandon the trial within days because it meant there were too many 'unknowns' and we couldn't clear IFR depatures from either Odiham or Farnborough.

[whowhenwhy]

The previous system still included many differences to ICAO SARPS & PANS though and really was not that different from the arrangements that we have today.
One of the problems with today's arrangements is that we've permitted the use of surveillance under a BS. Straight away this introduced blurring between BS and TS and thus confusion and by doing so undermined the main reason that we made the change in the first place.

[ATCO Fred]

See #71 above.
I think the problem with the previous system was that at some units 'FIS' traffic was identified, becoming 'known traffic' and hence passed 'generic traffic info' but at others they weren't, making them total unknowns and the passing of traffic info 'blurred' the border between FIS and RIS; introduction of Basic and TS was supposed to stop this but obviously hasn't as at some places, traffic requesting basic still needs to be identified to produce a 'known traffic' environment.
Years ago we did try doing this at Farnborough ie not identifying traffic requesting FIS but had to abandon the trial within days because it meant there were too many 'unknowns' and we couldn't clear IFR depatures from either Odiham or Farnborough.

Chevron I am somewhat perplexed by your post above. Their is no requirement to identify ac under a basic service / FIS nor has there ever been. Even when identified it does not constitute known traffic cause it can change level / heading with out telling you. There is no such thing as a 'known traffic environment' in class G airspace. These days there is only co-ordinated and uncoordinated traffic.

From the CAP774 Basic Service

A controller may identify an aircraft to facilitate co-ordination or to assist in the provision of generic navigational assistance, but is not required to inform the pilot that identification has taken place. Identification of an aircraft in receipt of a Basic Service does not imply that an increased level of ATS is being provided or that any subsequent monitoring will take place.

At our unit the boundary between Basic and TS is a pretty clear, you call relevant traffic for one (TS) - only collision risk for the other (BS) IF you happen to see it. If a controller/ FISO considers that a definite risk of collision exists, a warning shall be issued to the pilot (SERA.9005(b)(2) and GM1 SERA.9005(b)(2)) With both the pilot remains solely responsible for separation. However when vectoring to final approach we DO NOT vector into conflict - that does not sit within an appropriate application of duty of care.

[ATCO Fred]

The previous system still included many differences to ICAO SARPS & PANS though and really was not that different from the arrangements that we have today.
One of the problems with today's arrangements is that we've permitted the use of surveillance under a BS. Straight away this introduced blurring between BS and TS and thus confusion and by doing so undermined the main reason that we made the change in the first place.

For me there is no blurring but a distinct difference in the application of TS and BS. Perhaps Unit standards and the Unit Assessors need to be more pro-active. Surveillance under a BS / FIS has been going for 30 years so not sure what point you're trying to make there WWW?? Otherwise what the hell are you supposed to do with the BS service transit crossing you're final approach when you're vectoring inbound. With APS you can ID co-ord and carry on.

I'm really struggling to see the validity or relevance of " One of the problems with today's arrangements is that we've permitted the use of surveillance under a BS" as that is so far from reality. With Mode S and listening squawks it really allows approach radar to deal with the plethora of other aircraft operating within the vicinity of the aerodrome and it's approach paths easier, safer and minimises distractions and reductions in capacity.

[whowhenwhy]

ATCO Fred, sorry, I wasn't clear. What I mean is that the ability to provide surveillance derived traffic information to BS aircraft has blurred the line with TS. Fully agree that the use of surveillance to identify BS aircraft and 'integrate' them with IFR inbounds/outbounds has been essential. Of course, if the UK were to fully adopt ICAO then we would only provide ATC service to IFR flights inside controlled airspace and only provide FIS (not the fudge that it UK FIS) outside controlled airspace.