Radar Control Service in Class D VFR

[HeliComparator]

So, I am in UK, in receipt of a traffic service, I am approaching Class D airspace on a VFR flight, I request transit, I am instructed to route to a specific point within the Class D at a specified altitude. On entering the Class D, the controller says "Radar Control Service".

My question please is, what does that actually mean and where can I find it in print?

HC

[TCAS FAN]

As you are VFR an ATCO cannot technically require you to fly at a specific altitude/track as you may need to change either to remain VMC. Notwithstanding this, to expedite a CTR or CTA crossing it is a common practice to do it in the UK, I did it frequently, however with the proviso "advise if you require to change track or level to maintain VMC".

With respect to "radar control service" UK MATS Part 1 (CAP 493) requires ATCOs to change their service from an ATSOCAS when entering controlled airspace, in this Class D. However this opens a proverbial can of worms as to what is technically correct.

As you are VFR you cannot in the UK technically become a controlled flight as this could be seen as "controlled VFR" which is something that the UK does not practise, and would require Class C airspace to do it in. Class C control zones and lower airspace contol areas are not available in the UK.

My advice would be tell ATC if you expect/require to change track or level to remain VMC and put "radar control service" down to something that UK ATCOs have to say to avoid getting their knuckles wrapped by their unit examiners or the CAA.

[HeliComparator]

Thanks TCAS. My issue was not one of difficulty in maintaining VMC. I will await any further posts from pilots (because I realise I didn't know what this service means, and I suspect there are lots of pilots out there in the same boat) but in the mean time could you point me to a document describing what this service actually means?

HC

[Benet]

Radar Control Service

When aircraft are flying within controlled airspace such as airways, they are usually under the positive control of ATC. This means the controller will issue positive intsructions to the aircraft such as speed, level and heading control. Airacraft being transferred from one unit to the next remain under positive control and details of the flight are co-ordinated prior to handover by the controller.

From UK Air Traffic Control

The CAA website contains a document relating to Radar Control Service in Class D airspace which was withdrawn in 2003. I suspect it's obsolete!

[HeliComparator]

A bit of a dearth of replies makes me think everyone else is as much in the dark about RCS as me. So next question, whilst in receipt of RCS in Class D when VFR, what should ATC do with regard to preventing you from crashing into someone else?

HC

[SUMBURGH DIRECTOR]

HC,
RCS means that
a) you are inside controlled airspace
b) you are receiving a surveillance service

Flying VFR inside CAS you will be provided with traffic information against other VFR, SVFR and IFR flights. No "separation" is established.
However to facilitate safe and orderly integration of VFR/IFR traffic inside class D and around airports, some forms of positive controlling are applied, even though they are not aimed at establishing "separation" per se, such as orbits, visual reporting, holding points, VFR/SVFR routes, flying not above/not below a certain level etc etc


I now quote CAP493 (Manual of Air Traffic Services) (some of it doesn't really apply to most ATC units with processed radar data, but anyway..)

Provision of Surveillance Services
1.1.1 Surveillance services comprise:
a) separation of arriving, departing and en route traffic;
b) vectoring;
c) position information to assist in the navigation of aircraft;
d) monitoring traffic to provide information to the procedural controller;
e) assistance to aircraft crossing controlled airspace.

1.1.2 Before a controller provides any of the above services he shall either:
a) identify the aircraft, using a method appropriate to the surveillance system in use;
or
b) have had the identity of the aircraft transferred from another controller.
The act of identifying an aircraft does not imply that a service is being given.

1.1.3 Surveillance systems may also be used to provide the following, whether or not the
aircraft has been identified:
a) Information on the position of aircraft likely to constitute a hazard;
b) Avoiding action;
c) Information about observed weather for pilots and other controllers; and
d) Assistance to aircraft in emergency

1.1.4 Surveillance services shall be provided to the maximum extent practicable to cover
the operational requirement subject only to workload, communications or equipment
capability.

1.1.5 Regardless of the type of airspace, or the air traffic service being provided, nothing
shall prevent a controller from taking action he considers appropriate if he believes a
risk of collision exists

1.2 Type of Surveillance Service
1.2.1 The airspace within which the aircraft is flying determines the type of surveillance
service available, as shown in the table below.

Type of Airspace - Surveillance Service
Controlled Airspace - Radar Control Service
Outside Controlled - Airspace Deconfliction Service or Traffic Service


1.2.2 Pilots must be advised if a service commences, terminates or changes when:
a) they are operating outside controlled airspace; or
b) they cross the boundary of controlled airspace

1.3 Radar Control Service
1.3.1 A Radar Control Service may be provided to aircraft operating IFR, Special VFR or VFR.
When providing the service controllers issue instructions to which:
a) pilots of aircraft operating IFR are required to comply; and
b) pilots of aircraft operating Special VFR or VFR will comply unless they advise the
controller otherwise.
NOTE: The manner in which VFR flights under Radar Control Service may be safely
integrated with the IFR traffic flow in the vicinity of aerodromes is described
in Section 3.
1.3.2 Before an aircraft enters controlled airspace the controller must establish which flight
rules the pilot will be operating under.
1.3.3 Before a Radar Control Service to IFR flights is terminated procedural separation must
be applied, except at ACCs when an aircraft will be entering an adjacent sector and:
a) a radar handover has been given; or
b) the conditions of any standing agreement have been met.

Hope this helps, although I understand it is not a very straight forward read.

Simple practical example:
IFR flight on short final ILS. VFR aircraft wants to transit through the overhead at the same time, at 1000' AGL.
By the book, the requirement would be to say to the VFR flight "GABCD, traffic is B747 2 mile final runway 27" and to the B747 "Traffic is cessna 152 east of the field etc etc routing east to west via the overhead at 1000' has you in sight (or not).

However this is such a critical phase of the flight that to avoid the unnecessary RT and to protect the landing traffic from a potential go around it is much easier and safer to hold the VFR transit one side of the field and as soon as there's a suitable gap in the sequence of the landing IFR traffic bring the VFR across.
This judgement call is made by the Tower man but if there's a busy sequence of inbounds coming in and no "gaps" to allow this transit the controller may suggest a rerouting, or ring the radar man and ask for a gap, he will then extend someone else downwind for a couple of miles etc etc so that there is enough room to bring the transit across.
Very simple and basic example but also shows how sometimes the reason for an instruction you are given by a controller may not necessarily be on the same frequency or possibly quite a few more miles down the line.

I realise it's a bit of a long convoluted message but it can be printed out and make for good toilet reading!!

regards

[TroyTempest]

I love the old terms that everyone used. Radar Contolled Service. Ahh. Even foreign pilots understood ATC.
Maybe drifting off track, but what happened to Radar Advisory Service, etc. At least the pilot from overseas could guess what it meant! Deconfliction Service seems politically correct to someone, who doesn't know!
But I'm sure this has been covered.
Sumburgh, you do cover the Radar Control Servive for ATCO. I would always follow Radar Control Service near zones, bur Radar Advisory Service outside was understandable.

[HeliComparator]

Thanks Sumburgh

A few thoughts:

The doc you quote from is an ATC doc, not normally read by pilots.
The doc still doesn't actually say what the service entails, only the conditions for giving it etc.

Do any pilots know what service an RCS actually gives?

I'll reveal my hand now! The reason for the question was as follows:

In receipt of traffic service, get clearance to transit Class D at 2500' VFR via theshold of a runway (so to a specific point in space) so put that waypoint in FMS and fly towards it at 2500'. Controller says "radar control service" as I enter CAS. He mentions a light aircraft that is also crossing via the same point. His clearance is "not above 2500'" and he reports he is 2300'. Although it is gin clear, I can't see the light aircraft yet but feel that RCS means that ATC are looking after me. However I start to get a bit uncomfortable because i don't know from where or to where he is going, just that at some point he is going to be at the same place as me at nearly the same height, so I request climb to 3000'. This is denied me, I must remain at 2500'. I am on approach frequency, it's in the evening and have heard no other traffic.
Finally I see the traffic at a mile or two (which is a realistic distance to be able to see a light a/c below you) and he is going right to left with enough bearing change to mean I am not going to hit him, but pass behind. ATC offers me an orbit if I wish but if I do that, I will probably lose sight of him so don't.

We are now about 0.5 miles from the threshold. If I were not under RCS I would have changed heading a bit, but feel I must comply with ATC instructions, after all I am not going to get closer than about 300 metres and i will soon pass behind.

But just as he comes into my 12 o'clock he banks steeply to the right so is now directly in front of me on the same track. I am doing 155kts, he perhaps 90 so he is getting bigger in the windscreen very quickly. I have to take an evasive manoeuvre by banking 30 deg into an orbit.

So as I understand it, RCS means that you must do what the controller says, but he has no obligation to stop you hitting something and is within his rights to direct 2 aircraft with very different speeds to the same point is space to arrive at the same time. Something is wrong with that system!

HC

[TroyTempest]

If you are VFR in Class D and the controller says Radar Control Service, then a Cessna or stealth fighter hits you? Remember who's in charge, not always ATC?

[HeliComparator]

I agree Troy, and that is why I didn't hit him! But being under RCS made me reluctant to deviate from my clearance, resulting in me getting closer than I would have done if I were just on a general VFR clearance such as we normally get in Aberdeen.

Seems to me : No-one (as in pilots) knows what a VFR RCS entails and if they did, they would not like it!

HC

[ShyTorque]

The acceptance of radar control doesn't mean that you can't ask to change the clearance given if unhappy at any time. I sometimes do this even SVFR in Class A.

[10W]

1.3.1 A Radar Control Service may be provided to aircraft operating IFR, Special VFR or VFR.

When providing the service controllers issue instructions to which:

a) pilots of aircraft operating IFR are required to comply; and
b) pilots of aircraft operating Special VFR or VFR will comply unless they advise the controller otherwise.

HeliComparator,

If I understand correctly, your clearance was to transit VFR via the threshold. That means the navigation is up to you, as well as the separation from other aircraft. If you need to adjust track to avoid another aircraft, there's nothing to stop you doing it. If the controller wanted you to follow a specific route or track, he would have issued you with a heading or a restriction (e.g. fly no further East than the Mxx motorway). You are then responsible for advising if at any time you can't comply.

I think you are getting too hung up on the words Radar and Control. It's Radar because surveillance is available and this can be used in a manner of different ways as detailed in a previous post. It's Control because you are no longer outside Controlled Airspace. Control does not necessarily mean rigid though. It can be done with a light hand by using level blocks (e.g. not above/below a level) or general routeings (e.g. via a VRP or an Entry/Exit lane).

If you don't think VFR and 'self separation' is a good thing, think about what the alternative would be. A rigid IFR type system with Controlled Airspace entry severely limited as the controllers would have to provide positrive separation between all aircraft. That would severely limit the capacity of many Class D areas and result in lots of refusals or delays for transit aircraft. That's not a road I would like to go down, either as a pilot or controller.

[HeliComparator]

Shy - if you read the post again you will see that I did ask for a change of clearance but it was refused

10w your last para first, yes of course I do think self separation is a good thing.

2nd para quite agree, I was too hung up on RCS and now realise that I didn't really know what it meant. In fact I still don't know what it means and no-one so far has been able to point me to a written description so perhaps that is not too surprising. Certainly the name to me implies more rigid control and this was compounded by fixed altitude. The tone of the controller when I asked for altitude change was a littile along the lines of "you just do as you are told and everything will be fine".

This is the intended main thrust of this thread.

As far as the track went, it wasn't "direct to the threshold" but when things got sticky I was nearly over the threshold so a deviation at that point would have meant I didn't comply with the clearance.

Perhaps it boils down to what one is accustomed to. At my home airfield in Class D when we fly VFR it is just that. Only when IFR do we hear "Radar Control Service" . At the airfield I was transiting they clearly have a different policy in that all VFR traffic is told "RCS". I think that is the root of my being misled and just goes to show what lack of standardisation does. Perhaps there are 2 groups of pilots, one who routinely hear "RCS" and to them it just means "fly VFR", another who don't. For the latter I think there is a danger of not understanding what is meant, and that is due to the choice of its name and seeming lack of any information being promulgated about it.

From your lack of comment I presume you think the controller showed good practice when he cleared 2 aircraft to the same place to arrive at the same time, same altitude?

HC

[10W]

2nd para quite agree, I was too hung up on RCS and now realise that I didn't really know what it meant. In fact I still don't know what it means and no-one so far has been able to point me to a written description so perhaps that is not too surprising. Certainly the name to me implies more rigid control and this was compounded by fixed altitude. The tone of the controller when I asked for altitude change was a littile along the lines of "you just do as you are told and everything will be fine".

I agree that the term is not widely publicised and it's not surprising it means many different things to many people. Perhaps the CAA should consider publishing details about the services inside Controlled Service through the Airspace & Safety Initiative, similar to those they brought out for ATSOCAS ? That would clarify it for everyone.

In the same way that a pilot tells a controller he is unable to comply with an instruction, I think controllers should also tell pilots why they are unable to approve any request. Controllers have the big picture and so it might not always be apparent to the pilot what the problem is. Unfortunately, like all walks of life, there are some controllers who have attitude problems and forget the 'S' in 'ATS' stands for Air Traffic SERVICE.

As far as the track went, it wasn't "direct to the threshold" but when things got sticky I was nearly over the threshold so a deviation at that point would have meant I didn't comply with the clearance.

Remember that you can deviate from a clearance if the safety of your aircraft will be compromised. Ideally, tell the controller you are doing it first, but if it is urgent, make the manouevre and call as soon as you can thereafter. You have the ultimate responsibility for avoiding collisions, so ensure that becomes your priority.

At my home airfield in Class D when we fly VFR it is just that. Only when IFR do we hear "Radar Control Service" . At the airfield I was transiting they clearly have a different policy in that all VFR traffic is told "RCS". I think that is the root of my being misled and just goes to show what lack of standardisation does. Perhaps there are 2 groups of pilots, one who routinely hear "RCS" and to them it just means "fly VFR", another who don't. For the latter I think there is a danger of not understanding what is meant, and that is due to the choice of its name and seeming lack of any information being promulgated about it.

I think it needs split down even further. There will be 2 different methods depending on whether your flight originates and remains inside Controlled Airspace, or whether you are joining or transiting from outside Controlled Airspace (regardless of the airspace at your departure airfield).

If you start off in Class D, ATC will give you an appropriate clearance, but will not generally give you the service being provided. You will be expected to know that it is a Control Service, and although strictly speaking it could be either Radar or procedural, it doesn't make a lot of difference since the 'contract' you have with ATC (for Control Service) is already a given.

If you are joining or transiting, then you have been subject to a different set of services (or indeed no service at all) prior to entering Controlled Airspace. ATC must advise you of any change in service and you cannot receive the ATSOCAS services within Controlled Airspace. ATC therefore have no choice but to tell you what your new service is. That will be either Procedural Control service (no surveillance available) or Radar Control service.

If you leave Controlled Airspace, then once again ATC have to advise you of the change in service. This could be by asking you what service you require from them, by transfer to another unit, or by terminating their service and clearing you to contact whoever you wish.

From your lack of comment I presume you think the controller showed good practice when he cleared 2 aircraft to the same place to arrive at the same time, same altitude?

Yes. You are both VFR. You are both responsible for your own separation and none is provided by ATC. The only requirement is to provide salient traffic information to the pilots to assist them in separating themeselves. If you want something more, then IFR or SVFR should be the flight rules you fly under

[SUMBURGH DIRECTOR]

HC

the example you provide to me sounds like poor controlling. Regardless of the flight rules, ATC has a responsibility to prevent collisions between known traffic.
The minimum service offered by ATC to VFR flights inside CAS is traffic information on all other known flights. That is the MINIMUM. Nothing is to stop the controller to take further actions to prevent an unsafe situation developing.

At your home airfield, when arriving VFR, you will go directly from outside CAS on offshore deconfliction to Aberdeen Tower which being a Tower doesn't provide you with a radar service. That's why you won't get the RCS transition as you would normally do when arriving IFR via Aberdeen approach and director.

I would be interested to know what airport you were transiting in the example you provided. Were you given o'clock type of traffic information?

Remember that if you felt it was too close for comfort, or you had to take avoiding action, even if it's VFR vs VFR you are fully entitled to file an airprox. They get taken very seriously and investigated thoroughly and could lead to a good lesson to be learned.

10W.. I take it you work en route? Do you get many VFR - VFR conflictions in the airways?
I don't think clearing 2 a/c to same place same level at same time is a great idea, even if VFR.

[HeliComparator]

10W thanks or the detailed response. Clearly you are quoting the "party line" and you are correct within the context of the systems currently applied by ATC. My point is that the system is IMHO not a good one from the pilot's point of view, not well understood by some pilots including me ( a TRE with more than 10000 hrs) and not promulgated to pilots in any way that I can find.

In terms of it's name, "radar control" implies positive control like IFR, and as for "service" I struggle to see what benefit I am receiving from this "service". I must do as I am told and only deviate if I am about to crash. Seems like ATC has all the power but no responsibility, and the only ones benefitting from the service are ATC.

In terms of your last para, I think you make the point well that ATC have lost the plot with regard to what they should be trying to achieve, and a great deal of this results from the first priority being to not get sued, flight safety is somewhere further down the list. Please don't take personal offence by my comments, it is an institutional issue not a personal one.

[HeliComparator]

Sumburgh - many thanks for your support, part of the reason for this thread is to decide what if any action I should take, in terms of an Airprox the outcome will of course be "no risk of collision", so maybe just an MOR, but as I allude to in the reply just made, I feel ATC culture is increasingly following an agenda where "arse covering" is the highest priority and that is a shame because there are many great individual controllers for whom safety is the highest priority ( yourself included I am sure).

HC

Ps no clock codes as far as I remember, just info that another aircraft was crossing via the same point.

[SUMBURGH DIRECTOR]

Ps no clock codes as far as I remember, just info that another aircraft was crossing via the same point.

That is poor controlling IMO. Conflicting traffic, same level, same place, with you expressing concern (as demonstrated by the request for a change of level).

I'd like to know where it happened, if you don't feel like doing it publicly you could do so via PM. Thanks

[10W]

HeliComparator

Please don't take personal offence by my comments, it is an institutional issue not a personal one.

None taken. The debate is useful.

I feel ATC culture is increasingly following an agenda where "arse covering" is the highest priority and that is a shame because there are many great individual controllers for whom safety is the highest priority ( yourself included I am sure).

It's wider than that. It comes from society in general. That said, the VFR 'rules' are not something new. The requirements and responsibilities have been there as long as I remember and come from internationally agreed practices. If the industry and pilot community want them to change, there are various umbrella groups who have the ability to try and change things, first nationally, then internationally. I am not sure there is any underlying support to change anything though. Changes would only introduce even more 'control' and regulation and that's a Pandora's box that GA pilots shouldn't want to open.

Ps no clock codes as far as I remember, just info that another aircraft was crossing via the same point.

Without the controller report, there could be legitimate reasons for this, for example, the other aircraft not identified and thus not receiving a surveillance service. Normally however:

Whenever practicable, information regarding traffic on a possible conflicting path should be given in the following form:
a) relative bearing of the conflicting traffic in terms of the 12 hour clock with the optional prefix ‘left or right’ as appropriate; or, if the aircraft under service is established in a turn, the relative position of the conflicting traffic in relation to cardinal points i.e. northwest, south etc.;
b) distance from the conflicting traffic;
c) direction of flight of the conflicting traffic; and
d) relative speed of the conflicting traffic or the type of aircraft and level if this is known.

From the preceeding post:

Clearly you are quoting the "party line" and you are correct within the context of the systems currently applied by ATC. My point is that the system is IMHO not a good one from the pilot's point of view, not well understood by some pilots including me ( a TRE with more than 10000 hrs) and not promulgated to pilots in any way that I can find.

It's not so much the party line, it's the procedures published by ICAO and the CAA. The controllers have to work under the same rules as the pilots, although the levels of education between the two sides are of course differing in some cases. I don't mean that as an insult, just a fact that a 20 hour GA pilot or an IFR 747 pilot may not have the depth of detail that the controller is required to have, nor be aware of all the nuances, especially if they are not regulars to the airspace or the procedures being used. A controller using it every day will have a very high level of knowledge of the theory and the practical rules. They need it to practice their black arts

In terms of it's name, "radar control" implies positive control like IFR, and as for "service" I struggle to see what benefit I am receiving from this "service". I must do as I am told and only deviate if I am about to crash. Seems like ATC has all the power but no responsibility, and the only ones benefitting from the service are ATC.

A few more CAA quotes which might help

Radar Control - Term used to indicate that radar-derived information is employed directly in the provision of air traffic control service.

An ATC service is provided according to the particular circumstances and class of airspace, for the purpose of:

a) preventing collisions between aircraft in the air;
b) assisting in preventing collisions between aircraft moving on the apron and the manoeuvring area;
c) assisting in preventing collisions between aircraft and obstructions on the
manoeuvring area;
d) expediting and maintaining an orderly flow of air traffic.

So that's the service you receive. Point a) is the thrust of this thread. The controller's job is to prevent collisions between aircraft in the air. As it states, this depends on the circumstances and class of airspace. Ultimately, the circumstances and airspace class dictate that a VFR-VFR encounter/confliction requires no separation standard to be applied in Class D airspace, at least by ATC. The controller is not required to give you any, but he is required under the ICAO and CAA rules to give you traffic information which will help prevent that collision. If based on that information, either you or the controller are unhappy, then one of you has to raise the ante and ask for something else. In the controllers mind however, you are VFR and in visual conditions, you have been given the information. That's totally acceptable right up until the point where you have said you can't see the traffic and need another course of action. In this case the controller has a duty to reassess the situation and help you out. That help may have come from the other pilot calling that he has you in sight and is happy, it could be an orbit, or something else. Or it could be the controller assessing that you were not going to hit each other (either vertically or laterally) and so no other course of action was deemed necessary. Without appropriate RT and radar recordings, it's hard to tell if he performed badly or not.

Your last sentence is wrong. ATC have the responsibilities laid down as the service. Their responsibility for the provision of separation is also laid down as mentioned, dependent on rules of flight and class of airspace. But, there are also pilot responsibilities which are laid down under the rules which you elect to fly. If a pilot is VFR, he can't just ignore the see and be seen principles, the rules of the air, and airspace classifications, and then do the Telegraph crossword expecting ATC to move everything out of their way. Pilots need to know what is expected of them and know how ATC can help them comply with their responsibilities. It's a two way street, but in VFR, most of the requests and initiations to avoid collisions have to come from the pilot who a) knows what he can and can't see and b) knows what is the best course of action in preventing any potential collision.

The benefits of the service are that IFR and SVFR flights, whose visibility may be limited, operate in a known traffic environment, where separation is assured. The benefit for VFR flights are that they can operate in a known traffic environment without the need for IFR ratings or equipment, and follow the VFR rules and conditions within Controlled Airspace which might otherwise be off limits to them (e.g. Class A) with a little help from ATC in identifying potential conflicts.

In terms of your last para, I think you make the point well that ATC have lost the plot with regard to what they should be trying to achieve, and a great deal of this results from the first priority being to not get sued, flight safety is somewhere further down the list.

ATC has always had the service goals quoted above. Nothing has changed in that respect in the last 30 years. The only change is the introduction of a Duty of Care. The test of whether this is complied with is to ask what a reasonable person would have done. Not in your specific example, but as a generic statement, I would argue that a reasonable person who granted 2 VFR aircraft a clearance and told them about each other, in the absence of any other information from either pilot, would be compliant. In turn, would it be reasonable for either of the pilots not to speak up if they were not able to separate themselves ? I think not, and your specific issue indicates that you probably think so too. Without a full investigation and report, no one will ever know the issues in your case, so please file an Airprox if you are unhappy.


Sumburgh Director

At your home airfield, when arriving VFR, you will go directly from outside CAS on offshore deconfliction to Aberdeen Tower which being a Tower doesn't provide you with a radar service.

But they must provide a change of service surely if the aircraft is entering from outside Controlled Airspace ? It's mandatory to do so.

Remember that if you felt it was too close for comfort, or you had to take avoiding action, even if it's VFR vs VFR you are fully entitled to file an airprox. They get taken very seriously and investigated thoroughly and could lead to a good lesson to be learned.

I agree. The Board which investigates has a broad panel of expertise which is helpful to everyone.

10W.. I take it you work en route? Do you get many VFR - VFR conflictions in the airways?

I don't think clearing 2 a/c to same place same level at same time is a great idea, even if VFR.

We get them occasionally, but they are not frequent. Sometimes they are even gliders, so 'control' is a bit of a misnomer as there is little they can follow in terms of a clearance.

You think it's not a good idea, I think that's over-control, which is a particularly British disease As a VFR GA pilot, I know my responsibilities and the last thing I want is ATC telling me to do this and do that in respect of another aircraft who I can see and avoid myself. On the occasions I can't see it, I'll do what HeliComparator did and ask for help. Many busy VFR places would grind to a halt if we had to start applying 'separation' between VFR aircraft which is effectively what you are suggesting. How would ATC ever be able to clear more than one VFR in the circuit ?

[HeliComparator]

10w in general I agree with nearly everything you say, for my particular event it comes back to my perception of being "forced" onto a collison course by ATC, having my attempts at applying vertical separation refused, with the consequence that, rightly or wrongly, I felt I must comply with the clearance until the point where doing so would have caused a collision and thus had to take "emergency" action rather than earlier action that would have been more comfortable.

I asked more TREs at work what Radar Control Service for VFR meant, none of them really knew and they had similar ideas to my original feeling that it gave some degree of safety / separation from other traffic. So it's primarily for that reason that I have now filed an Airprox.

HC