Advisory Routes v. RAS

[parkfell]

Interesting experience the other day. On our way down in a Saab from Kirkwall to Glasgow: Scottish [129.225] provided a RAS, but against "participating traffic only".

Would I be right in thinking that if unknown traffic were to appear and perhaps become traffic to me, the service I was receiving would not, from a purely legal point of view, not cover this situation?

For the avoidance of doubt, I am certain that the controller would apply a large measure of common sense should this occur. Is this some form of weasle wording just in case the unknown conflicting traffic was not spotted in time to prevent a close encounter.

I hear that the days may well be numbered for class F airspace. Any update on this?:)

[radar707]

The service you receive provides standard separation against participating traffic, i.e 5 miles 1000ft. If non participating traffic were observed you would be provided with traffic information and avoiding action if appropriate.
The RAS is just an advisory service, if you are visual with the non participating traffic and happy that separation will not be compromised then you can say so and the controller will let you carry on your merry way to EGPF

[chevvron]

If you were under RADAR advisory, you should expect separation from ALL other traffic; it's only under ATAS ie procedural that you would be separated from participating traffic only.
As far as I understand it, class F will still exist below FL195 for the time being with Advisory Routes having an upper limit of FL195; wef 15 March Advisory Routes presently between FL195 and FL245 will become class C airways, and all other airspace presently class A, D or G will also become class C

[anotherthing]

The wording is slightly poor... a RAS will give you standard separation against participating traffic i.e. traffic that is working that unit or another unit, under coordination.

The controller will try to keep you separate from non participating (unknown) traffic, but may not be able to provide standard separation if the unknown traffic suddenly appears.

On other words, 'participating' or 'known' traffic is controlled in such a manner that using vectors/levels the controller will provide separation. He/she can obviously not do this to traffic that is flying around, not talking to them. In these instances, the traffic will be called and vectors provided to achieve 5 miles separation where possible.

If you are good VMC and happy to continue, you can tell the controller... you then become responsible for separation against that A/C - you can do this as many times as you want for any number of A/C, however the controller is still required to attempt to provide you with separation against other unknown traffic.

You do not have to be visual with the contact to do this. The usual call is along the lines of "Gxxxx is (good) VMC and happy to continue"

Remember that under a RAS, if you elect to provide your own separation against an unknown target, you MUST advise the controller if you change heading or level (for obvious reasons, you may be on vectors to provide separation against other traffic... if you change heading without asking, this could compromise the separation)

[throw a dyce]

Parkfell,
I think the controller is saying the correct thing.With the amount of military traffic that blasts around Scotland,and the very sudden way they can become traffic,it's not always possible to give instant traffic on unknowns.
It's not always possible for the military to stay out of CAS,so in Class F and G you're sitting ducks.As for airlines that fly in Class G when there is controlled airspace available,then it's staggering.When neighbours say they are flying a certain airline which operates in Class G out of Aberdeen,I offer them my old binoculars.Why? So you can watch the airshow around you.:oh:

[Chilli Monster]

Parkfell,
I think the controller is saying the correct thing.
I disagree.

The critera for a RAS in respect to standard separation between known traffic, and the possibility of not achieving standard separation from unknown traffic are the same no matter what the airspace.

Surely the correct phraseology should have been;

"Radar Advisory Service, standard separation will be maintained from participating traffic only"; or, even better

"Radar Advisory Service, standard separation may not be achieved from non-participating traffic"

Subtely different, but less ambiguous and nearer the true meaning of what was probably meant.

[Widger]

Chevvron. Not totally correct. Only SOME ADRs will become Class C above FL195. Others will be removed. Class F up to FL 195, Class C with no route FL195 to FL245, UAR above FL245. The AIC should contain the information.

[radar707]

A radar advisory service (RAS) is an air traffic radar service in which the controller shall provide advice necessary to maintain prescribed separation between aircraft participating in the advisory service and in which he shall pass the bearing distance and if known level of conflicting non participating aircraft together with the advice on action necessary to resolve the confliction. Where time does not permit this procedure to be adopted, the controller shall pass advice on avoiding action followed by details on the conflicting traffic.

We do not provide separation against ALL traffic only against PARTICIPATING traffic and advice on avoiding UNKNOWN traffic. We aim to ACHIEVE 5 miles or 3000ft if possible against unknown traffic but can only guarantee separation against participating known traffic.

A Radar Advisory Service is just that ADVISORY. Pilots are not required to comply with ATC instructions.

[anotherthing]

radar707

i think you will find thats exactly what i said in my first post!

[throw a dyce]

Chilli Monster,
I think the appropriate phrase is ''Radar Advisory Service''. The extra information is only when you limit the service for whatever reason.
That controller is only covering his/her back because between EGPA and EGPF is prime military country.

[threemiles]

Participating or non participating?
why not: all above FL100 and around major aerodromes Class C, below and elsewhere Class E - as in many many other countries? No need to look at a chart. Uncontrolled military flying in IMC to happen in reserved areas with restricted access for anybody else.
Is there a civil pilot out there who really WANTS to fly under IMC in uncontrolled airspace?

[ToweringCu]

Because there are other airspace users other than commercial and military, who would not be able to comply with the restrictions of class C and hence couldn't go above FL100. We've got enough controlled airspace as it is.
The controller was wrong; he told you that because he didn't want to give avoiding action against unknown traffic, or because he didn't feel able to. There is no such thing as a 'RAS against participating traffic'. The service should have been limited due to high traffic density, or downgraded to a RIS.

[NorthSouth]

There is no such thing as a 'RAS against participating traffic'. The service should have been limited due to high traffic density, or downgraded to a RIS.That's surely right - if he was giving a RAS against participating traffic, what was he giving against non-participating? Presumably a limited RAS or a RIS? But you can't give 'half a RAS' - that would be a recipe for confusion and misunderstanding. You give the pilot *a* service and he reads it back to confirm he knows what he's getting. Most pilots haven't a clue what a Limited RAS or RIS is anyway, unless you spell it out clearly - "possible late warnings of traffic from below due to the base of radar cover" etc. Or maybe it should be "Limited RIS because I'm spending so much time telling you about the limitations I haven't got time to tell you about traffic."
When is the ATSOCAS review reporting anyway?
NS

[chevvron]

ATSOCA review has only done stage 1 so far - what the operators want us to provide; what we are able to provide comes next!
NB: One of the things they wanted was an INCREASED level of service in busier areas!

[HEATHROW DIRECTOR]

<<Is there a civil pilot out there who really WANTS to fly under IMC in uncontrolled airspace?>>

I don't know... but very many do.

There seems to be so much confusion about RAS/RIS both on the part of controllers and pilots that I thank my lucky stars that I always worked in Class A (which I'd love to see more of!).

There's a major airfield not a million miles from me outside CAS where many comemrcial foreign crews operate; big aeroplanes too - BBJs, etc. As soon as they're airborne, or just as they leave CAS comes the inevitable question: "What type of radar service do you require?" The majority of pilots apparently don't know as only about 10% ever answer correctly!! When they do answer, ATC immediately responds with some spiel about service being limited due to radar suppression, traffic density, etc..... is it really worth it? Such airfields ought to be surrounded with Class A and major air routes serving large commercial jets should be Class A too so everything is under radar CONTROL.

[bookworm]

why not: all above FL100 and around major aerodromes Class C, below and elsewhere Class E - as in many many other countries? No need to look at a chart. Uncontrolled military flying in IMC to happen in reserved areas with restricted access for anybody else.
Is there a civil pilot out there who really WANTS to fly under IMC in uncontrolled airspace?

Yes.

You make the implicit assumption that in VMC the risks of flying in airspace with unknown traffic are substantially less than in IMC, presumably because of the ability to "see and avoid". Unfortunately that's not the case. The chances of seeing another aircraft on a true collision course in time to avoid it is uncomfortably low at modern aircraft speeds, even in good VMC. The advantage in IMC is a significantly lower traffic density in airspace shared with GA users, gliders and microlights.

[throw a dyce]

Bookworm,
Have you seen the Military in full flow?When you pass traffic on targets doing 500kts in Class F and G,the civilian pilots are alarmed.This is not about GA traffic,but high performance fast jets conflicting rapidly with fast moving civil traffic.The trouble with Advisory routes is that the military basically treat them like they are not there.They are not participating,so conflictions are often very rapid.Closing speeds 700+ kts so you get very little time,and nowhere to go.
As for more CAS,then the Military rule the roost again.When P18 was introduced south of Aberdeen,it's about as useless as a chocolate spacesuit.Only active when the chaps are asleep or pissed in the bar.But the base of other airspace was raised,so unpressurised aircraft has little or no enroute CAS at all.
There is very little CAS north of the Scottish TMA,but a hell of a lot of Class F and G.I have seen so many nasties,close calls,whatever you want to call it in this airspace that any controller who covers their back cannot be criticised.Even pilots of a certain Dutch airline don't understand Radar Advisory. They think that they are under Radar Control.:ugh:

[bookworm]

Bookworm,
Have you seen the Military in full flow?When you pass traffic on targets doing 500kts in Class F and G,the civilian pilots are alarmed.This is not about GA traffic,but high performance fast jets conflicting rapidly with fast moving civil traffic.The trouble with Advisory routes is that the military basically treat them like they are not there.They are not participating,so conflictions are often very rapid.Closing speeds 700+ kts so you get very little time,and nowhere to go.

That makes my point nicely, I think. At a closing speed of 700 knots, it really doesn't matter if you're in VMC or IMC. You're not going to see it in time to avoid it.

It's time we stopped kidding ourselves that unassisted (whether by ATC or TCAS) self-separation is adequate in VMC but not in IMC.

[Chilli Monster]

I think the appropriate phrase is ''Radar Advisory Service''. The extra information is only when you limit the service for whatever reason.

Yes, quite agree, but
That controller is only covering his/her back because between EGPA and EGPF is prime military country.

Sorry, go back and read what they said again. I'm in the same camp as NorthSouth and Towering Cu.

What was posted (which is what we presume he said) is that he would provide a RAS between participating aircraft only, (which is wrong - he's providing an ATC service with standard separation between participating aircraft) and so has left parkfell to believe (and has been summised by others) that if there's any other traffic then - sorry mate, you're own your own.

No matter how you try and defend it you have a case of very poor, highly ambiguous phraseology.

If he wanted to cover his own back then one of my suggestions would have been a better use of phraseology, OR limit the service, OR downgrade it to a RIS (probably the best option).

[The Fat Controller]

If an aircraft is flying on an ADR, he either gets a procedural advisory service or a radar advisory service.
You CANNOT downgrade to a radar information service on an ADR.
It's as simple as that.
Therefore you are obliged to give avoiding action against unknown aircraft if you are providing RAS.

[DFC]

If an aircraft is flying on an ADR, he either gets a procedural advisory service or a radar advisory service.
You CANNOT downgrade to a radar information service on an ADR.
It's as simple as that.
Therefore you are obliged to give avoiding action against unknown aircraft if you are providing RAS.


If the aircraft on the ADR is to one side of the centerline are you obliged to provide a standard 5nm from say a VFR flight operating just outside the ADR boundary say some 3nm away?

or

If you vector traffic to one side to provide radar separation against opposite direction participating traffic for a level change are you obliged to provide standard separation from traffic operating outside and remaining outside the ADR which may be some 3nm away?

or

A non-participating flight is climbing straight down the middle of the ADR. Do you vector the participating traffic off the ADR and out of class F to separate from observed non-participating traffic while risking a close call off the ADR?

Regards,

DFC

[Inverted81]

one of the numerous grey areas. dont ya love em? :eek:
lateral dimensions of an advisory route? just as ambiguous as "in the vicinity of an aerodrome"

I agree with Towering Cu re: the limiting of the service, due to flying through areas of high traffic density. (as per MATS 1)
A little more to the North East of EGPA the services are limited to SSR only operations. I think this is just a good old case of incorrect (non standard) phraseology.

Another interesting topic of conversation recently has regarded the "clearance" required to cross an ADR, above levels under your responsibility whilst under an ssr only environment. is it a clearance?
Discuss.... :ooh: :ooh:

[chevvron]

When I did my cadetship, an Advisory route was 'deemed to be' 10 miles wide; has this changed then?

[Inverted81]

When I did my cadetship, an Advisory route was 'deemed to be' 10 miles wide; has this changed then?

Ok... unless this is something i'm being a total @rse about... it could be..... anyone confirm this?

[PPRuNe Radar]

Inverted81

UK AIP ENR 1-1-1-1 Para 1.2

Advisory Routes have no declared width but for the purposes of ATS provision are deemed to be 5 nm either side of a straight line joining each two consecutive points.

DFC

If the aircraft on the ADR is to one side of the centerline are you obliged to provide a standard 5nm from say a VFR flight operating just outside the ADR boundary say some 3nm away?

Firstly, how do you know it is a VFR flight, unless it is known traffic ? If it is known traffic and VFR, then no separation by ATC is provided or required. Traffic information is also not required by the letter of the law but most controllers would provide it under a duty of care I expect.

If you vector traffic to one side to provide radar separation against opposite direction participating traffic for a level change are you obliged to provide standard separation from traffic operating outside and remaining outside the ADR which may be some 3nm away?

Standard separation is only provided between participating IFR flights in Class F so there is no obligation to provide it against traffic outside the ADR. However, if it is known that the other aircraft is IFR, or it is unknown traffic, then controllers will aim to provide standard separation if possible. If it is known to be VFR, no separation is required.

A non-participating flight is climbing straight down the middle of the ADR. Do you vector the participating traffic off the ADR and out of class F to separate from observed non-participating traffic while risking a close call off the ADR?

Standard separation is only provided between participating IFR flights in Class F so there is no obligation to provide it against non participating traffic within the ADR. However, if it is known that the other aircraft is IFR, or it is unknown traffic, then controllers will aim to provide standard separation if possible. If it is known to be VFR, no separation is required.


Chilli Monster

No matter how you try and defend it you have a case of very poor, highly ambiguous phraseology

This is the crux of the matter. The controller was not entitled to make the statement (if quoted correctly) that the RAS was against participating traffic only. No such get out clause exists.

[parkfell]

No doubt the LCEs will add this debate to their question bank.