A few CAS questions

[jack-oh]

I have a couple of questions and wondered if anyone could help.

1. Now that Prestwick has got its CAS back is it only Norwich that provides a civil radar App service outside of CAS?
2. If so can anyone at Norwich tell me how "civil" answer the age old question of what type of service an ac is under when its conducting an SRE/ILS approach?
3. Has anyone out there worked Cass C airspace in a terminal enviroment ie surounding the aerodrome. Was it overly complicated to separate VFR and IFR ac.
4. Why has the UK never adopted Class C, is it because it requires permanent radar cover and no way of working if the radar fails. I am specifically intrested in terminal rather than high level.

I thank you for your time in advance.

[DFC]

Norwich isn't the only place.....Farnborough springs to mind.

Aircraft on SRA to airfield in Class G;

UK - Radar Advisory Service.

ICAO - ATC Service using radar. Separation only provided between that flight and other flights known to the ATC unit.

Class C from experience presents no real problem from an ATC point of view with regard to the integration of VFR and IFR flights provided that some careful planning has been put into the routing of VFR flights within the airspace.

The UK uses mostly Class D airspace for control zones but in practice, ATC generally apply the rules appropriate to class C when dealing with VFR flights. I have yet to hear of an ATCO brave (crazy) enough to clear a VFR flight to cross the zone through the ILS with simple traffic info on the stream of B737s zipping down the approach.

There is no requirement for radar to use class C. In most cases, the VFR flights follow routes that are deemed separated from the various approach and departure tracks of IFR flights in local procedures.

As a simple example;
Remember the old 45 degree track separation rule....so provided the VFR flight turns left or right by 45 deg or more after departure, the IFR can depart straight ahead.

Also, separation can be reduced in the vicinity of the aerodrome by the ADC.

Regards,

DFC

[matspart3]

1. No. Southend, Exeter, Humberside, Gloucester, Filton, Chester and Cambridge all provide Approach Radar services outside CAS

2. Radar Advisory Service...sometimes 'Limited' due traffic density or sometimes even a series of vectors for 'tactical purposes' under Radar Information

3. Some Class D units seem to apply Class C criteria anyway for VFR!! DFC's post refers!!!

4. I'd be happy with Class E...at least it would appear on the map and offer a bit of protection to IFR traffic operating outside CAS

[vintage ATCO]

1. Lots of examples given.

2. Radar Advisory, Radar Information (you can radar vector under RIS these days) or even Procedural Approach, you don't 'need' radar, although there will be varying descriptions of 'need'!

3. Yes, we have debated this many times on PPRuNe! It all comes down to how happy an ATCO is opertaing VFR traffic inside a Class D zone against IFR traffic.

4. I'd be interested in an experiment to try Class C.

VA

[Chilli Monster]

2. If so can anyone at Norwich tell me how "civil" answer the age old question of what type of service an ac is under when its conducting an SRE/ILS approach?
It's probably worth pointing out here that a lot of civil units are now stipulating an altitide below which they will not provide RAS, and an SRA is often carried out below this level, so technically even if the aircraft was under a RAS it should have been downgraded to a RIS if unit instructions make the above stipulation.

As for vectoring for the ILS, and the vectoring and intercept takes place above this minimum level then the service the aircraft is under is what has been agreed in the initial contact (remember it's a verbal contract and should be mutually agreed and not imposed) - so it can be RIS or RAS taking into account unit instructions.

jack-oh - I take it by your question you're leading up to an oft quoted mis-conception that you cannot vector under a RIS? If so then as matspart3 states yes you can vector 'tactically', you just can't vector to avoid. Of course - you're not going to point it straight at another aircraft intentionally of course, but at least during the final stages of the approach you are only required to pass traffic info if necessary. This has the added advantage that the aircraft may not discontinue the approach unless he wished - often a better situation in a training environment.
3. Some Class D units seem to apply Class C criteria anyway for VFR!! DFC's post refers!!!
Some - I'd say most!
4. Why has the UK never adopted Class C, is it because it requires permanent radar cover and no way of working if the radar fails. I am specifically intrested in terminal rather than high level.
Seems to work fine in Ireland, some of which are procedural, not radar. If anywhere was the perfect candidate then it would have to be the Channel Islands CTA, rather than having it class 'A' which is completely over the top.

[055166k]

Amazing to read that Prestwick get Controlled Airspace protection on the basis of 11000-odd Air Transport Movements per annum whereas Bristol International with 50000 ATM's has to make do with a modestly-sized zone and absolutely no links to CAS whatsoever......and they operate in one of the busiest and most complex areas in the UK, certainly with regard to the scope and variety of military interests. Must be a political thing because in no way can it be a question of safety......unless different criteria apply in Scotland.

[vintage ATCO]

It's probably worth pointing out here that a lot of civil units are now stipulating an altitide below which they will not provide RAS, and an SRA is often carried out below this level, so technically even if the aircraft was under a RAS it should have been downgraded to a RIS if unit instructions make the above stipulation.

Do you mean once the SRA has commenced or during the intermediate approach? If the former then surely once within the final approach sector obstacle clearance is assured which is the point of a minimum level for RAS in general.

VA

[1261]

055166K - we've been through the PK thing before, remember!

http://www.pprune.org/forums/showthread.php?s=&threadid=103082

[055166k]

Quite right....but it must be kept in the frame because the speed at which the industry is changing demands action for safety. Nearly all UK airspace is based on the traditional big airport hubs of quarter of a century ago. My professionalism leads me to demand that I am given the facility to do my job properly , namely adequate protected airspace. To ignore the massive growth in the use of regional airports is to bury one's head in the sand.......and those operators pay the same as everyone else. The latest hub is Exeter which was already a busy airport.

[jack-oh]

Thank you for your replies. I am more than happy with vectoring under RIS however it often becomes a moral dilemma especially when the ac you are driving around the sky can't see the other ac you are pointing him at. Following an incident or accident when both ac got too close no one is going to thank you for knowing the rules off by heart, especially when it is you that have in effect orchestrated the whole thing. The other point about what type of service you are under on final instrument App is one the Military always have difficulty with; if you were RAS prior to the FAF you would have been given avoiding action on unknown traffic, if however you are on the PAR/SRA/ILS and something pops up what do you do? Equally the radar contacts that may be in the vis CCT are not avoided as this would mean no one would ever do an instrument APP. However, that doesn't mean to say that one of those radar contacts is not a to##er in a glider that has decided to cross the airfield and not bother to speak to anyone. (Yes, it does happen). The other question about Class C was out of pure interest as RAS would seem, on paper, to afford more separation from traffic than those in Class D. I understand the point about a known traffic environment, but that doesn't mean that everyone who declares themselves VFR has necessarily got the exact VMC criteria, or that the see and avoid principle works with ac that have vastly disparate speeds. Having recently come back from the USA (name dropper) most Mil airfields are in some form of CAS the preference being Class C as this regulates separation from VFR and IFR. Personally, I would like to see the UK Mil experiment with this approach around a busy group of airfields.

[M609]

I think you will find MIL airfields with CAS in most coutries in europe, other then a certain island....... ;)