IFR or VFR? [Archive] - PPRuNe Forums

airac

28th May 2008, 08:20

Section 1 Chapter 3 Page 1
Mats pt one Lists the situations where standard separation is to be applied

g) IFR flights in Class G airspace being provided with a service by an Approach
Control unit;
That statement does not specify what type of service ie procedural or radar.
If you have two IFR A/C and the service is approach procedural no one could argue that standard separation must be provided ( whether or not the pilots wish to comply is another matter).
The anomaly ( point of discussion ) appears to be when two A/C are being provided with a RIS .
i.e no avoiding action , just traffic information.
My point is that separation standards, be they based on time or distance must always be provided ,the beauty of Radar services means that the standards can be reduced to 3nms ( or 5nms) or 1000'.
Therefore if you have two IFR A/C on a RIS the separation that I must apply is at least 3nms or 1000', hence the need to establish the A/C's flight rules.
Do the panel agree or disagree?

5miles - panel people like yourself :D

mm_flynn

28th May 2008, 08:56

As just a humble pilot, I always thought there was no separation provided in Class G, other than advisories when under RAS.

My experience is that enroute controllers almost never ask if one is IFR or VFR when OCAS and that on a nice day, including IFR in your details doesn't reliably get RIS/RAS over FIS. I have found that a radar unit providing 'radar enhanced FIS' (i.e. Farnborough) will 'upgrade its offer of service' from FIS to RIS if I indicate I am IMC.

Also, if I am on a 'proper IFR FP' (i.e. one processed by CFMU) then any segments OCAS seem by default to be under RAS.

Finally, probably more related to the specific thread, the approach controllers do seem to ask and then provide standard separation when inbound or outbound to their field (places like Oxford, Lydd, Shoreham, etc.), but this doesn't seem to happen as reliably when transiting their service area.

Dont tell um pike

28th May 2008, 09:57

I think this topic was mostly covered a while ago but essentially two procedural IFR aircraft will get procedural separation (1000ft, time, distance, what ever) two IFR aircraft on a RIS will get a RIS (traffic info etc)
How different units / controllers go about trying to work with these rules is another matter, but it'll all change soon anyway...hooray!!
DTUP

HEATHROW DIRECTOR

28th May 2008, 09:59

<<Finally, probably more related to the specific thread, the approach controllers do seem to ask and then provide standard separation when inbound or outbound to their field (places like Oxford, Lydd, Shoreham, etc.), but this doesn't seem to happen as reliably when transiting their service area.>>

I worked at Oxford many years ago, but I expect the basic situation is similar now. We would provide what was virtually a full control service to Oxford traffic and others which wished to participate. We would often have half a dozen twins in the hold, sometimes practicing in VMC but at other times making genuine instrument approaches in bad weather. I still have nightmares about the pilots who would come on frequency out of the blue and say something like: "Shortly passing your overhead, FL45 IMC, do you have any traffic?" when there was traffic 500ft above and beneath them. They obviously had every right to be where they were without talking to an ATC unit but to this day I'm amazed there wasn't a mid-air.. or two! There's probably a radar service there now...? We would have provided separation had they called in time, as many did.

DFC

28th May 2008, 12:53

passing your overhead, FL45 IMC, do you have any traffic?" when there was traffic 500ft above and beneath them

Indeed - a transit in a West to Northwest direction. I bet you are glad they were not transiting South to Southwest in direction!! which leads nicely to the point -

The approach controller has 3 IFR points with no lateral separation. One Southeast bound at FL55, one Northwest bound at FL65 and one Southwestbound at FL60. All flying in class G and all complying with the quadrantal rule as they are required to do.

Has it changed that 500ft is no longer acceptable combined with essentail traffic information in class F and G airspace?

If so then assuming the controller puts the flights at FL50, 60 and 70 who is responsible for the one at FL70 having a collision with an unknown IFR flight northeast bound at FL70?

If the quadrantal rule for F and G airspace porvides some limited reduction in the chances of a collision, why throw it out the window?

Regards,

DFC

BurglarsDog

28th May 2008, 12:53

Depends who is working the traffic. As a mil ATCO I believe that you will have no requirement to ascertain IFR / VFR (if this is still the case). The responsibilities of all parties are covererd by type of service requested, that agreed, and airspace classification - normaly G for the Mil. So RAS gets the turns etc in an attempt to separate and RIS / FIS fly merrily on their way albeit at 420kt plus sometimes! As a civil ATCO you of course will have your own docs and procedures and duty of care considerations, which if memory serves me right are more ICAO based than the JSP'S the Brit Mil use. So if you need to separate participating IFR /IFR OCTA then fill your boots and good luck.

Class C / D it all above say FL100 and standardise training and licensing!

Who needs tactical freedom these days anyway!

DogGone

chevvron

28th May 2008, 13:57

mm_flynn

28th May 2008, 15:04

IFR or VFR makes no difference unless the pilot requests RAS; what IS necessary is to get away from the concept that the controller 'does not need' to know whether you are VMC or IMC; in my opinion this is essential information for the controller.why? (slightly rhetorical as it is clearly of minimal use to provide a FIS to someone who has no chance of seeing any traffic when you could provide a RIS/RAS.)

In real life a chunk of UK GA pilots are pretty confused about flight rules vs met conditions - which is why you guys sometimes get 'I am VFR in IMC' from people OCAS not on an IFR FP and/or below the TA. The fact the service can be influenced more by your flight conditions than your flight rules doesn't help reduce this confusion.

Life's a Beech

28th May 2008, 15:04

Use the Force

What's wrong with a FIS under IFR? Certainly in good VMC it is just as safe as flying VFR under a FIS (potentially safer in that at least the aircraft should be flying correct semi-circular or quadrantals, not mandatory under VFR). What else should I ask for when getting a service from London Information, for example?

Heathrow Director

There's no radar service at Oxford. Very professional procedural approach control. Occasionally some very gash pilots using it, as it is not as simple for a pilot to use as a radar service nor are all the procedures straight-forward, but that's not Oxford's fault (nor in the worst case I experienced was it a based aircraft, so I'm not getting at OATS or anyone specific).

Chevvron

That ain't what I've been told by a procedural approach controller. My pilots are all told to give flight rules on the first call, or asap if they forget then. I do encourage them to give flight conditions too, although that is surely less directly relevant.

Use the Force

30th May 2008, 10:57

All well and good flying the quadrantal rule until you fly in close proximity to an airport that is vectoring IFR aircraft at numerous levels, departing to sector safe altitudes or higher, using two different transition altitudes because of your airports position in the country.
The IFR aircraft that I was referring to was the idiot in cloud, not sector safe, wanting no help and not giving any consideration to the other IFR aircraft wishing to take off and land at a class G airfield without being vectored around the whole bloody sky.
I have seen aircraft speaking to London Information transit straight through a busy ILS (marked on a bloody map by the way.) and transit through class A airways, obviously not coordinated. London Information has a place do not get me wrong. On this congested island during a weekday however I would like to think there is enough military and civil radar units open to give you a great service from top to bottom. (maybe not Wales)

Riverboat

30th May 2008, 22:55

"Use the Force" - please belt up! I think you are verging on the ridiculous! For a start, you should attempt to understand pilots and their job. You are there to help pilots, not to dictate, even though I appreciate there are places where you can legally dictate, and when you do that is still for the benefit of the pilots and the aircraft they fly.

But you can't dictate in Class G, thank goodness. If pilots call you and ask for an FIS without referring to their flight rules or flight conditions, just be pleased that they called you! At least you now know they are there, or, if you already knew they were there, who they are and where they are going and at what altitude or flight level.

I think LARS was created more to benefit aerodromes who otherwise didn't know who or what was flying around their airspace than for the transitting aircraft. It may have changed a bit, in that pilots feel comfortable with a LARS service, but often an FIS, even when technically flying IFR, is entirely acceptable to the pilot. He or she knows what he/she is doing. You should not assume that pilots are all idiots. (Personally I prefer an RIS most of the time). A request for an FIS usually means "I am quite happy looking after myself, thanks a lot, but you can now call me if you want to."

If flying through Class G I will usually call airports/aerodromes/LARS on or close to my route, because I know you would like to know about me. You also might want to ask me to turn left, right, climb or descent for some important reason. Good - you can now do it.

But what I don't want is unnecessary interference with my Class G flight. Whether I am IFR or VFR is usually irrelevant, and that is my business. Whether I am IMC or VMC is also my business. I might ask for a service and you might agree to provide it.

But if you see a possible confliction, and you need to establish whether I am IMC or VMC, then ask me. That is sensible and of course I will willingly tell you. If you need to know something, ask and I will tell you. But don't think that pilots in Class G should always tell you their inside leg measurement right from the start, because they don't have to, and I recommend they don't bother. Otherwise ATC will take over the world, and then "God help us!".

Burglars Dog - I totally agree with your view on this issue.

Riverboat

airac

31st May 2008, 09:01

MM_ flynn. Several years ago it was stated that IFR A/C in class G would not be separated , At the time I was informed by ATS SRG that as Approach controllers we would still have to provide separation as it is laid down in MATS pt 1 ,and since our licence wa based on procedures in that book we would still have to provide it.

DFC would agree but the quadrantal rule does not establish standard separation

BurglarsDog Vive la differance.

Use the Force, Steady!!

River boat, likewise, calm down its only a discussion.

Clearly no one can decide whether separation must be applied or not ,which is obviously not ideal. Perhaps the editor of MATS pt 1 should clarify, however as the book stands, I believe, I still have a duty to apply standard separation to IFR A/C as per MATS pt 1.

Spitoon

31st May 2008, 09:48

What seems to be behind the original question and some of this debate goes far wider than whether IFR gets separated in class G airspace.

The root of the problem is the way that the UK implements ICAO standards and PANS. The procedures in MATS Part 1 is based on the procedures for doing ATC in PANS-ATM. However, these procedures assume that there will be CAS in the area because elsewhere ICAO says that CAS should be established to protect IFR routes. ICAO provides for IFR flights outside CAS but - because they're outside CAS - doesn't have any procedures for providing such flights with ATC.

But the UK doesn't establish CAS where it might reasonably be expected to because of the number of IFR flights/routes....and then provides ATC to some of the traffic flying along these routes (using pretty much the same procedures as work inside CAS). It's no wonder that there are anomalies in the services that exist outside CAS!

In order to accommodate these UK arrangements we invent things like ATSOCAS with RIS and RAS. These services are at odds with what pilots from other states (which follow ICAO more closely) will understand - and offer a significant opporunity for interpretation to individual ATC units and controllers applying the procedures. As DTUP points out it's all going to change soon and the last set of procedures that I saw called all of the services outside CAS FIS....even though some of the services are control! No doubt this will clear everything up.

It will probably all change again before too long. The UK is going to be audited by ICAO in the next couple of years - it will be interesting to see whether the UK way of doing ATS outside CAS generates any findings. The last ICAO audit, which didn't look at ATS, seemed to generate quite a lot of action in response to the findings.

And then there's EASA. In the next two or three years it seems likely that EASA will become responsible for setting the rules for ATS and aerodromes across the EU. It seems doubtful that the UK's way of doing things outside CAS will survive long under that regime.

DFC

31st May 2008, 09:58

DFC would agree but the quadrantal rule does not establish standard separation

Yes but separation standards are minima.

One aircraft inbound IFR to the beacon at FL45 (northwestbound), aircraft transiting through the overhead northeast bound at FL50.

Do you (a) drop the inbound to FL40 and risk being responsible for putting the aircraft at the same level as an unknown Southwestbound flight or (b)do you push the transit up to FL70

Sems to me that (b) is the option with the less risk.

Of course this problem would be simply solved by providing class E airspace at aerodromes with instrument procedures.

Regards,

DFC

rogervisual

31st May 2008, 10:06

Although not too many units are approach procedural these days, to those units that still are, it is essential that they know whether a pilot is VFR or IFR. When a pilot comes onto the their frequency and informs them he is IFR they are duty bound to provide standard separation against other known IFR traffic. Unless the pilot says he does not wish to take part in the service being provided (bad airmanship if he chooses not too, if you ask me) as it is class G airspace. The problem you have if a pilot does not want place himself under your approach procedural control service is that you still have to protect the other IFR traffic against him where possible.
It would be interesting to see how that situation would play out if there was a incident involving that aircraft, could it not be deemed that he/she was endandering his and other a/c by refusing a ATC service which is there for his/her flight safety.

airac

31st May 2008, 11:21

DFC
Take your point ,however you have area's where CAS is FL45 or less so pilots cannot comply with the quad rule as they would then be inside CAS.

Spitoon , it'll certainly be interesting when the audit takes place, as for changes well we will see, the proximity limitations on ATCO licences (if an ATCO has one) was supposed to be lifted in April but as yet it is still in force.
I cannot see, in these days of litigation ,something that was considered unsafe 'ish one day being allowed the next simply because ICAO deem it so.

Spitoon

31st May 2008, 13:44

I was thinking more in terms that things that are done today - like ATC outside CAS - being stopped after the ICAO audit.

Of course, safety is a slightly different issue. Just because something is an ICAO SARP doesn't mean it will always be safe. This is why I am a believer in a sensible safety management approach (note, not necessarily the sort of SMS we are seeing demanded by some regulators in Europe today). I see ICAO SARPs as minimum standards which are there for a variety of reasons, although an important one is safety.

Use the Force

31st May 2008, 20:11

Riverboat

I do understand that we are there for you. I think you took what I said rather personally though.
I was not referring to all pilots, but there are the odd few. People who fly aircraft are not always doing a job and maybe their training was not as good as yours!!!!!

You should see my wife drive!!

rogervisual

1st Jun 2008, 19:34

Riverboat
Before you go off about understanding pilots , practice what you preach.
Your comments show you have no idea what a Approach Procedural Controller in class G does (he/she does not have a radar). Your attitude towards ATC and the service they provide you insults all the pilots out there with the right attitude. Your use of the word dictate with regards to ATC says a lot about you. (was there a bad experience with the headboy at school you need to talk to someone about) Do aviation a favour stay on the ground.

Riverboat

2nd Jun 2008, 02:24

Thanks Airac: you are right to ask me to calm down. I do get a bit aeriated with ATC pomposity, as exibited by rogervisual! And "Use the Force", what I meant to do was robustly defend Class G, not have a go at you specifically. Sorry I did so, and thanks for your response.

Rogervisual, I am not, I think, as ignorant as you might think, but i will accept that I was not considering the procedural Approach Controller's problem. I suggest you take this up with the CAA. I am just stating that Class G is Class G and there are no requirements to even talk to ATC in Class G unless entering ATZs - as far as I am aware. (Open to correction.)

That procedural approach controllers have problems with this situation is not really my fault. Perhaps there shouldn't be a procedural approach taking place in that airspace at all? Or, if it is deemed to be appropriate, some consideration must be (and obviously is) given to the fact that maybe aircraft will be passing through the approach without calling anyone, quite legally. The onus is on you, the approach controller, to deal with this, not to place the blame for any conflicts on the aircraft passing by without calling. (Not that I approve them not calling.)

Moving on logically, whether you feel it is sensible or not, an aircraft passing close by the approach who decides to call you doesn't have to tell you whether he or she is IFR, VFR, IMC or VMC. It might help you to know, but if it means that the transitting aircraft is messed about if he/she does tell you, maybe next time they won't bother calling you. After all, it is Class G.

I appreciate this is an unlikely scenario, and I am not recommending that pilots become arrogant and unreasonable, but it would help if the minority of ATCOs don't become arrogant and unreasonable too. It is bad enough trying to get through Class D some times and in some places, never mind the strict requirements of Class A. The only place where there is FREEDOM is Class G, and it seems that some ATCOs hate this.

The cause of Class G has to be fought!

Dont tell um pike

2nd Jun 2008, 06:52

DFC

2nd Jun 2008, 11:05

Perhaps procedural let downs should not be carried out in class G, but until all airfields with Approach aids are given Cat D protection its unlikely to change.

Why does the UK have such a love affair with class D?

Class D would totally inappropriate for Oxford but Class E should have been in place years ago.

Same goes for places that have radar such as Filton and Farnborough, Exeter and Coventry (which would have silenced most of the complaints regarding the class D).

Of course if class D is treated like class C then one would probably expect class E to be treated like class D - but that is a separate issue.

Regards,

DFC

mm_flynn

2nd Jun 2008, 11:43

RB

How can "any consideration be given to the fact that maybe aircraft will be passing through the approach without calling anyone ?" it's a non radar environment , if aircraft don't call we don't know you are there.

Perhaps procedural let downs should not be carried out in class G, but until all airfields with Approach aids are given Cat D protection its unlikely to change.

DTUP

( Head down awaiting incoming GA Salvo )INCOMING !!!
The UK seems to suffer with the concept of 'some control'. Certainly my experience of the operation of Class D UK airspace is that is much more like the American Class B (in terms of freedom of access and level of direction provided to VFR participants). VFR GA I think does have a genuine concern that increases in controlled airspace will significantly limit their access and hence fight tooth and nail against it. However, equally I have a huge level of sympathy for the guys at places like EGLF/EGKB trying to get IFR traffic away where they need to thread them through Class G airspace while trying to get a joining clearance - (and at EGKB on a procedural basis).

As an outsider to both camps, I do find it disappointing that many other countries seem to be able to mix IFR/VFR GA/CAT together in a more graduated system that meets many of the needs of all parties (rather than all of the needs of some, some of the time).

Dont tell um pike

2nd Jun 2008, 12:53

Well said :ok:

rogervisual

2nd Jun 2008, 20:21

You are right maybe there should not be any procedural letdowns in class G . But at present they are so we have to deal with it. Riverboat, you are correct, there is no legal requirement to talk to ATC , I just think it is good airmanship for your protection and the other A/C in the area. You are wrong as regards to the onus is on the Approach procedural controller , as he/she is only legally obligated to separate against KNOWN traffic. I know of several occasions where a A/C has transitted right through a published instrument approach lane without talking to the ATC unit and there has been a confliction with the A/C on the approach. The Controller is totally not at fault as the A/C was not talking to him , the CAA have then used adjacent radar units information for tracing action and the pilot has been reprimanded for poor airmanship for not contacting the unit. No controller wants to mess pilots about , we just want to be able to offer the best service available to him/her and to do this we need to know your flight rules at times.
The GA comminity get a raw deal at times in the UK and are unfairly pushed about at some airfields and as you rightly say, class G needs to be protected but we all need to work together.

Use the Force

2nd Jun 2008, 20:46

Common sense at last.

Riverboat, in a previous thread you spoke about the police going from A to B quickly, subjecting my friends in controlled airspace to excecute missed approaches. I think you came down on the side of the contollers.

My point is that this is infrequent, however it is something that us in class G suffer daily due to bad airmanship.

Should we sit down and have a long chat with them? As you stated about the Met. The same people who are just doing a job. Protecting you and me.

Riverboat

3rd Jun 2008, 00:14

Rogervisual and Use the Force - I think we are a lot closer in views that was first apparent. None of us want aircraft to be transitting approach paths without making a call. Wretched airmanship if they do. I appreciate your difficulties under these circumstances. I like the idea of Class E, requiring a call to be made. Makes a lot of sense.

Use the Force

3rd Jun 2008, 14:08

Thank you Riverboat, good response

DFC

3rd Jun 2008, 22:33

I like the idea of Class E, requiring a call to be made. Makes a lot of sense.

Only IFR flights are required to call and get a clearance.

VFR flights only get an FIS in class E if they decide to take the option of making a call.

Another reason for having class E in accordance with ICAO is that the VMC criteria require a VFR flight to be more than the common 1 milimetre away from cloud that goes for VFR in class G at lower levels. Thus giving the IFR pilot a fighting chance of breaking cloud and having a few seconds to spot the traffic.

It also prevents the scud running "VFR" arrivals flying in when it is OVC at 600ft in 1500m

Regards,

DFC

airac

3rd Jun 2008, 23:08

D F C sound logic
But we've more chance of getting poo from a rocking horse:ugh:

Keef

3rd Jun 2008, 23:54

The main factor that applies seems to be "big sky - small aeroplane."

Having IAPs in Class G relies heavily on the statistic that there has never been a collision between two civilian aircraft in IMC in uncontrolled airspace over the UK.

With radar, the odds are better, but with procedural approaches, I'm always wondering who else is out there. I've seen some very pretty aircraft quite close up in between the clouds.

Use the Force

6th Jun 2008, 21:40

The CAA state:

The UK does not except that class E airspace is a known enviroment and therefore will only grant this type of airspace in exceptional circumstances.

The quote is not perfect as I write from memory.

They say UK. Do they mean the CAA, Parliament, general aviators, or airport operators?

I am sure that if you ask airport operators they would prefer some protection rather than none, after all it is them who attract the wealth.

A local procedure for VFR aircraft to squawk a discrete code inside the control zone could help. If you are a non transponder just make a radio transmission and tell us your route. VFR aircraft by their nature use see and avoid and therefore class E will stop that one pilot from determining his flight rules by his flight conditions.

Class E is the way forward for aerodromes with instrument approaches currently in class G.

DFC

6th Jun 2008, 22:56

A local procedure for VFR aircraft to squawk a discrete code inside the control zone could help. If you are a non transponder just make a radio transmission and tell us your route. VFR aircraft by their nature use see and avoid and therefore class E will stop that one pilot from determining his flight rules by his flight conditions.

The whole idea of class E is to provide protection to IFR flights during the time that they are IMC and for a brief period after they exit IMC.

Class E is designed to permit VFR flights to operate with as few limitations as possible.

The idea is simple - IMC - you watch those instruments and will be separated from others doing the same. If VMC then look out the window.

Of course Class E is not a known evironment - VFRs can be there unknown. However, unless ther UK conceeds that it's pilots regularly fly in IMC on VFR flights then it can not say that class E is not a known environment for IFR flights.

---------------

If DAP proiposed class E for say Coventry then

The IFR brigade would not complain

The VFR brigade would not complain

The glider brigade would not complain

The commercial operators would not complain

ATC would not complain

Helicopter pilots and microlight pilots would not complain.

So who prevents class E..............?????

Oh yea - those that require tactical freedom and the ability to fly anywhere they choose - but know that in the real case they are very limited in where they can fly.

How many flights in Iraq can depart when they want - fly when and where they want and simply do what they want - 0 - so why not train more realistically!

Perhaps they forget that many MATZ could be class E.

Regards,

DFC

bookworm

7th Jun 2008, 08:24

Of course Class E is not a known evironment - VFRs can be there unknown. However, unless ther UK conceeds that it's pilots regularly fly in IMC on VFR flights then it can not say that class E is not a known environment for IFR flights.

An unknown environment with unknown VFR flights does not become a known environment for IFR simply because the weather conditions are VMC.

If see and avoid worked perfectly, class E would be the perfect airspace solution. But it's not even close to perfect, is it? The vast majority of collisions (and for what it's worth, Airproxes) occur in good VMC. You can either pretend that pilots of IFR flights are superhuman will detect all those unknown flights in time to avoid them, or you can get real and accept that in high traffic-density airspace only class C or above provides sensible protection. And in low traffic-density airspace, class G provides better operational flexibility.

mm_flynn

7th Jun 2008, 10:14

BW, Although I normally agree with you - on this one I think Class E could be a good idea. I grew up in US airspace which fundamentally works this system. It would be very good except for 1 thing - which I will pick up in a minute.

First the good.

IFR traffic from most airports leaves directly into CAS - therefore no vectoring around at low level waiting for a joining clearance

In IMC it is illegal rather than just 'not cricket' to track through an IAP without a clearance and everyone in IMC is getting separated from everyone who is supposed to be there! Happy(ish) IFR traffic, because of course they still need to separate themselves from VFR using see and avoid - but that is no different from today's Class G

You could even separate IFR and VFR traffic by 500ft (novel concept which could catch on elsewhere ;) ).

VFR traffic has no real change, other than actually needing a clearance to change to IFR (or go IMC!) Happy VFR traffic, but...

Bad News

There is no way UK ATC could provide the service needed unless the Class E airspace was very small... Unless of course they treat IFR transits in Class E like everyone else treats VFR transits in Class B

bookworm

7th Jun 2008, 17:30

IFR traffic from most airports leaves directly into CAS - therefore no vectoring around at low level waiting for a joining clearance

That's a comment about the coordination of ATC from minor airfield. Coordination could be effected just as easily from an airport in class G as in class E (and in many cases, it is).

In IMC it is illegal rather than just 'not cricket' to track through an IAP without a clearance and everyone in IMC is getting separated from everyone who is supposed to be there! Happy(ish) IFR traffic, because of course they still need to separate themselves from VFR using see and avoid - but that is no different from today's Class G

You can put the ICAO airspace classes into three groups. There are those (A to D) in which an air traffic service is mandatory at all times, because the traffic density is high enough that self-separation is not possible under any circumstances. There are those (F and G) in which an air traffic service is not mandatory, because the traffic density is low enough that the risk of collision is not significant. And then there is this funny halfway-house (E) where an ATC service is mandatory only in IMC. The only possible justification for this is that the risk of collision is not insignificant and that self-separation in VMC is effective and that self-separation in IMC is not.

A considerable body of research on see-and-avoid, as well as numerous mid-air collisions in perfect VMC refutes the idea that self-separation in VMC is effective. The zero-accident 50-year history of flight in IMC in uncontrolled airspace in the UK demonstrates that a combination of low collision probablilities and self-separation in IMC is effective enough. Together, they undermine the very raison d'etre of class E airspace.

Of course, that drives a hole through some of the fundamental features of the air traffic model that we have clung to for more than 60 years. The idea that self-separation is reliable in VMC but that other means are required in IMC is intuitive -- and also quite wrong.

Use the Force

7th Jun 2008, 19:31

BW, why is it that class G provides better operational flexibility over class E? Is it so you can fly through cloud without using a radio?

Also can you please tell me where abouts in England you can find airspace with low traffic density? Maybe I should move there. :\

A question for Europe:

How many other European countries have commercial Heavys flying through uncontrolled airspace? Not through choice.

(That is of course you can pull yourselves away from the football. I am not jealous at all.:{) Come on England!!!....No wait arghhhhhh.

airac

7th Jun 2008, 20:06

Whilst the discussion on types of airspace is interesting, I feel that the thread has wandered just a teeny bit from the original point.

This stemmed from some colleagues favouring the "continue VFR" phrase to establish A/C flight rules i.e. if they don't say anything Like " I am IFR " then one can assume that they are indeed VFR, to others ,who do not seek to establish the flight rules at all.
The latter apparently opening up a whole can of worms. :confused:
Don’t see it that way myself but whatever.
The outcome of establishing the "Rules" is that IFR, I have to separate as per MATS pt one, VFR I don't. Also that the separation of the said IFR flights must also be applied to A/C in receipt of a RIS.
Granted this is a UK thing but if any of my learned compatriots have an opinion then I would love to hear them.

Use the Force

7th Jun 2008, 21:00

Airac,

If you have two aircraft IFR under a RIS than it is the responsibility of the pilot to avoid each other.

The problem arises when you have multiple IFR aircraft, one wanting a RAS, one wanting a RIS and the nutter wanting a FIS.

Aircraft being sequenced (more than one inbound) onto an ILS must have a RAS. It is then the responsibility of the ATC provided to vector these inbounds around for a while until the transit is 5 miles away from them. You could limit the RAS because of traffic intensity, however if there is a problem, a court of law might not see it your way.

Use the Force

7th Jun 2008, 21:27

This happened today.

"GXXXX inbound."
"GXXXX, roger squawk XXXX, what type of service do you require?"
"GXXXX, I would like a radar service."
"GXXXX, would you like a RAS or a RIS?"
"GXXXX I will take an advisory service today."
"GXXXX you are below the sector safe altitude, RIS only or climb to X.XA."
"GXXXX roger climbing to X.XA."
"GXXXX what type of approach do you require?"
"GXXXX a VFR join."
"GXXXX RAS only available to IFR aircraft, RIS. :ugh:

It hurts sometimes you know.

Before you all start to preach about Deconflicting service, I do not wish to sound like Stephen Hawkings or GPWS and say. "Terrain, Terrain."

ATCO Fred

7th Jun 2008, 22:18

MM flyn - just to back track for a bit

Finally, probably more related to the specific thread, the approach controllers do seem to ask and then provide standard separation when inbound or outbound to their field (places like Oxford, Lydd, Shoreham, etc.), but this doesn't seem to happen as reliably when transiting their service area.

AIRAC

This stemmed from some colleagues favouring the "continue VFR" phrase to establish A/C flight rules i.e. if they don't say anything Like " I am IFR " then one can assume that they are indeed VFR, to others ,who do not seek to establish the flight rules at all..

I'm an ATCO at one of these units. If you transit and you are IFR you effectively block all other arrivals/departures for up to 20 minutes. (10 mins to the beacon and 10 out!). So, in order not to create delays we use our common sense. If its CAVOK and you do not specify that you are IFR you will be issued a VFR clearance; if this is not acceptable I expect you to say so. In poor weather, if you call at an altitude above the cloud base or I suspect you are IMC I will ask. This method works well in ensuring that everyone gets to go where they want to, in safety, with the minimum delay.

airac

7th Jun 2008, 22:23

Use the force
I have a couple of points
Firstly in the good book it states
Standard vertical or horizontal separation shall be provided, unless otherwise
specified, between:
g) IFR flights in Class G airspace being provided with a service by an Approach
Control unit;
It does not differentiate between procedural and radar.
Whilst I accept that a/c in receipt of a RIS are not given avoiding action, I believe this only applies to unknown A/C and not traffic working the same unit.
You mention a court of law scenario.
Barrister: - "So you were working both the A/C, Both were IFR and at the same height. Both were clearly visible on radar and you did not separate because they were only getting a RIS"
"What is your primary task?”
Me "preventing collisions between aircraft in the air"
Barrister," Didn't do a very good job then did we"
Secondly I take your point about the FIS but they might not be a nutter sometimes thats all I can give them.
Will the revised ATSOCAS remove this anomaly ,Nah ,same cr@p different names :rolleyes:

ATCO Fred

7th Jun 2008, 22:24

This happened today.

"GXXXX inbound."
"GXXXX, roger squawk XXXX, what type of service do you require?"
"GXXXX, I would like a radar service."
"GXXXX, would you like a RAS or a RIS?"
"GXXXX I will take an advisory service today."
"GXXXX you are below the sector safe altitude, RIS only or climb to X.XA."
"GXXXX roger climbing to X.XA."
"GXXXX what type of approach do you require?"
"GXXXX a VFR join."
"GXXXX RAS only available to IFR aircraft, RIS.

It hurts sometimes you know.

Use the force - and thus back to the old ATSOCAS 'gotchya'. The contract between pilot and controller is established by the pilot requesting the service and the controlling reading it back - that's the contract established. So....if you have a pilot who clearly doesn't appreciate the fundamentals of ATSOCAS (as above) how can he fulfill his side of the contract? Isn't the contract therefull null and void?

Fred!

bookworm

8th Jun 2008, 08:03

BW, why is it that class G provides better operational flexibility over class E? Is it so you can fly through cloud without using a radio?

Without the necessity for a clearance that provides standard separation, yes. All this controlled airspace being proposed consumes resources -- controller time and workload -- to manage. If the benefit of the provision is very low, those resources should be spent on something more effective. Class E also imposes cloud separation and visibility requirements on VFR flights that would not be imposed in class G.

Also can you please tell me where abouts in England you can find airspace with low traffic density? Maybe I should move there.

The traffic density in IMC is low (enough) in most places in the UK. If flying in IMC in uncontrolled airspace is so dangerous, where have they been hiding all the bodies over the last 60 years? ;)

Dont tell um pike

8th Jun 2008, 17:38

Airac

Case for the defense-:

Mats pt1 states "unless specified" , a Ris specifies no avoiding action shall be given ?

However throw in a bit of duty of care and it certainly is a gateaux and gluteus soirée.:rolleyes:

dtup

airac

8th Jun 2008, 23:29

DTUP
"unless specified" cant find that one
and still trying to figure out what cake and bum has to do with it:ok:
However
There lies the rub , whilst a RIS states one thing regarding conflicting TFC the Mats pt section 1 Standard separation bit states quite clearly another.
Anomalies or the different interpretation of various rules abound in the profession another good example is that of an A/C being cleared to approach maintaining VMC and their own separation.

Dont tell um pike

9th Jun 2008, 06:28

Airac

Couldn't agree more, god forbid it should ever come to a court of Law because I've got a feeling you'd been damned if you do and damned if you don't.

DTUP

bottom rung

9th Jun 2008, 07:55

Airac.... approach maintaining VMC was pulled a few years ago. An aircraft can climb or descend in VMC, but can't be cleared for an approach as such. As a result I tend not to descend IFR aircraft VMC or IMC below either the MSA or the lowest published level that an instrument approach can be authorised, unless the aircraft wants descent to MSA in anticipation of a visual approach or if the aircraft elects to go VFR.
How we separate (procedurally- no radar available) such IFR traffic against other IFR transits in the area is another matter. (Class G, no radar, mixing scheduled turboprops, GA, offshore rotary, mil and occasional jet traffic......).
There are still a few places in the UK where this is the norm.

airac

9th Jun 2008, 20:42

bottom rung
Yes I know it was pulled from the MATS but the following is still in the AIP Gen 3.3

5.4.3 Providing that it is not at night or in Class A Airspace, a pilot is entitled to ask ATC to cancel his IFR plan during his approach to land providing that he can continue in uninterrupted VMC. In this case, he must accept responsibility for maintaining his own separation from other aircraft.

5.4.4 An arriving aircraft may be cleared, by day only, to descend remaining in VMC and maintaining own separation if reports indicate that this is possible. Essential traffic information will be given.

Which any way you look at it is a VMC approach.

Incidentally to all avid readers of this thread, having just trawled through the LARS section it does state that

Reporting of flight conditions is not required unless requested by controllers

So perhaps we should also apply this to approach control as well
Any way I'm sure people are getting very bored with this now.:bored:
Thanks to all who contributed: ok:

bottom rung

10th Jun 2008, 07:59

Airac... the first quote relates to an aircraft that has specifically cancelled his IFR plan. It is not an approach maintaining VMC; the aircraft is VFR, not IFR. The second quote only relates to an aircraft descending VMC, not approaching maintaining VMC.

airac

11th Jun 2008, 18:55

Publication of ATSIN 132 puts this matter firmly to bed

6.2 Many of the changes to CAP 493 will be administrative in nature to reflect CAP 774; however, Section 1 Chapter 1 (Air Traffic Services) will require significant revision in order to reflect the amended services and to delineate clearly between an Air Traffic Control Service in controlled airspace, and the suite of services that form the UK Flight Information Services outside controlled airspace. The revised ATSOCAS are predicated upon pilots requesting the most appropriate level of service for their flight, rather than these being dependent upon flight rules. This is consistent with the advisory nature of ATSOCAS, in which the controller provides advice in order to enable the pilot to fulfil his/her responsibilities for safe deconfliction from other aircraft. Accordingly, it is therefore necessary to remove the current explicit requirement within CAP 493 to provide standard separation between IFR flights in Class G airspace that are being provided with a service by an approach control unit. The detailed rationale for this specific change, including the expected benefits and mitigations that ensure that the change does not adversely affect safety, is contained at Appendix D.:D