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Class D VFR/IFR separation standards

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Class D VFR/IFR separation standards

Old 24th Dec 2014, 20:45
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Class D VFR/IFR separation standards

Quick query for ATCOs working in Class D, I was out flying recently with a colleague routeing from Newtownards through Belfast and up towards Portrush. Beautiful day, CAVOK with not much traffic around. We requested a zone transit from Belfast City which we got, we were passed traffic information on a A319 on a 4 mile final runway 22 and I heard the controller passing traffic information to the A319 about us, we were visual with the landing traffic and the controller simply let us continue across the zone - no fuss, no drama, we passed behind the A319 and once through the final approach we were transferred to Aldergrove and were told they had our details. At this stage we were tracking towards Glengormley hoping for a zone transit from Aldergrove to head towards Portrush.

On first contact with Aldergrove we were asked to pass full details and intentions, somewhat surprised we went through the spiel anyway and were then told there was traffic inbound for runway 25 and to remain outside the zone. This we duly did but within a short time we became visual with an Easyjet on our right hand side at least 1000ft above, we reported visual with this traffic to the controller hoping for a transit but were told that we weren`t separated from the Easyjet and a zone transit was not available. my colleague confirmed we were VFR and good visual but there was still no transit forthcoming.

We continued outside Aldergrove airspace, there were no further inbounds and nothing that I could see to prevent transit.

Do Aldergrove now separate VFR against IFR traffic? Why?
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Old 24th Dec 2014, 22:16
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TCAS-event 'report-writing avoidance'?
ATCO doesn't understand Class D?

Give them a phone call and ask why they are not managing their airspace i.a.w. Class D procedures.
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Old 24th Dec 2014, 22:20
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Don't know the airspace but you appear to be saying that both are class D. There's no requirement to separate VFR from IFR in class D, but the rather poorly defined role of the controller to maintain a safe, orderly and expeditious flow of traffic means that there is a lot of variation in what individual controllers (and some ATC service providers) will do. Also remember that each situation is different and the full traffic situation or workload may not be apparent from the viewpoint of one aircraft.

Having said all that, in my view, there is a lot of unnecessary overcontrolling in class D airspace in the UK, with many controllers by preference or local procedures applying standard separation in such cases. Many moons ago, when I was an operational controller, I worked a pretty busy class D airspace and found the flexibility it gave (to the controller) to be great. If there was a reason to keep aircraft apart, you can do it but on a nice day you can let people get on with what they want and throw in the necessary traffic information. On the other hand, I can recall, and sympathise with, some of my colleagues who had found themselves having to explain why two aircraft got close enough for an AIRPROX to be filed because a VFR flight was unable to follow simple instructions or to judge what a safe distance from the other aircraft looks like; after such an experience, a few colleagues took the safe option and effectively separated all aircraft.

I have no idea whether any of this was at the root of your experience in NI but I hope it goes some way toward explaining the inconsistencies which exist.
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Old 24th Dec 2014, 22:31
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Completely agree with talkdownman. Suggest you ring up EGAA and ask to speak to the SATCO as it would appear one of his controllers is not understanding of the rules within the airspace he is providing a 'service'
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Old 25th Dec 2014, 06:58
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When the U.K. airspace re-classification occurred, (sometime in the 1990s I think), our CTR went from 'Rule21' to class D. There was no training, and little guidance from unit management, about handling VFR traffic. Certain procedures, originally designed to keep SVFR and IFR traffic apart, were kept in place as they also helped reducing 'non-standard' IFR routings, and therefore noise.
Is the integration of VFR/IFR traffic taught on the APP or APS course at CATC these days?

Last edited by ZOOKER; 25th Dec 2014 at 14:00.
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Old 25th Dec 2014, 14:06
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this "too busy" thing is getting a bit tiresome ! Bit like "for "security reasons"
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Old 25th Dec 2014, 16:38
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MATS Part 1 Section 1 Chapter 5

Control of VFR Flight
5.3 The minimum services provided to VFR flights in Class D airspace are
specified at Section 1, Chapter 2, paragraph 2. Separation standards
are not prescribed for application by ATC between VFR flights or
between VFR and IFR flights in Class D airspace. However, ATC has
a responsibility to prevent collisions between known flights and to
maintain a safe, orderly and expeditious flow of traffic.
This objective i
s met by passing sufficient traffic information and instructions to assist pilots to
‘see and avoid’ each other as specified at Section 3, Chapter 1, paragraph 2.

5.4 Instructions issued to VFR flights in Class D airspace are mandatory.
These may comprise routeing instructions, visual holding instructions,
level restrictions, and information on collision hazards, in order to
establish a safe, orderly and expeditious flow of traffic and to provide for
the effective management of overall ATC workload.

5.5 Routeing instructions may be issued which will reduce or eliminate
points of conflict with other flights, such as final approach tracks and
circuit areas,
with a consequent reduction in the workload associated
with passing extensive traffic information. VRPs may be established to
assist in the definition of frequently utilised routes and the avoidance
of instrument approach and departure tracks. Where controllers require
VFR aircraft to hold at a specific point pending further clearance, this is
to be explicitly stated to the pilot.
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Old 26th Dec 2014, 09:51
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Quick question.Was you're aircraft displaying SSR and Mode C ?
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Old 26th Dec 2014, 10:29
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Thanks for the response to date, I think the best bet is to try and speak to someone in Aldergrove over the next few days. I was talking to a controller at Belfast City and he was somewhat bemused but said he wasn`t in the least surprised by anything that Aldergrove do these days. I tried to get him to elaborate but he also said I should try and contact them myself.

The aircraft is full mode s/c equipped and it is working!
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Old 26th Dec 2014, 11:54
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That's a pretty standard ATC response. We all do things better than the units next door.
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Old 26th Dec 2014, 18:39
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City and Aldergrove have always (well certainly in the past decade or so) behaved differently. Personally, I think City have it right whilst Aldergrove tend to manage the sky like Class C. I does make one wonder whether the regulator is doing it's job properly; there's certainly a lack of standardisation.
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Old 28th Dec 2014, 17:12
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Now I am really confused! I got speaking to a controller at Aldergrove and he has said that they are required to separate ALL traffic regardless of weather, types, performance etc. They will not allow for example a microlight in the same sector as an airbus unless they are separated - I`m not sure where their sectors are and I`m not sure if this is a NATS thing or a local unit thing. Either way it seems to be creating a lot of work for the controllers!

When I explained the scenario I experienced he simply said that even though we could see the big shiny jet we simply were not considered separated in his opinion and therefore wouldn`t get a transit. I asked what if the airbus had been a VFR PA28 and we could each see each other, he said we still wouldn`t be classed as separated.

I went back to the guy I spoke to at Belfast City and he said if he applied those rules then City couldn`t function as they simply don`t have the space to operate this way, he said they regularly have helicopter traffic operating over the city centre at 3000 feet with an outbound IFR also going to 3000 feet, traffic information is passed and that`s it.

What happens at other areas??
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Old 28th Dec 2014, 17:55
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VFR / IFR separation standards in class D = pass traffic information.

Confirm VFR?
Transit clearance issued.
VFR pilot reports visual.
See and avoid.
Happy days.

I'd be on the phone to the Manager ATC in the New Year to ask why EGAA controllers aren't operating class D airspace correctly (based on what has been posted by pan x 4)
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Old 28th Dec 2014, 18:54
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I wonder if this is specifically a lack of ATCO standardisation as opposed to unit standardisation.

I used to operate in and around Belfast (both airports) quite a lot and I am sure I remember being allowed to self separate with traffic in sight in Aldergrove CTR. I have also spoken to the guys and girls there before about a couple of issues and they have been very friendly.
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Old 28th Dec 2014, 19:09
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Quick question,

In the UK do you need 'clearance' to enter Class D airspace VFR? My experience with D is from the US and as VFR traffic you only need to establish two-way com with ATC before you can enter. With that said, in certain extremely busy situations the controller have just told me to stay outside their airspace. No problem to comply in that case.
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Old 28th Dec 2014, 19:27
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Yes a clearance is required.

Airspace class - Wikipedia, the free encyclopedia
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Old 28th Dec 2014, 20:05
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If I remember correctly, Class D replaced the U.K.'s 'Special Rules Airspace' and the mnemonic for that was 'COLO'........

CONTACT the relevant ATC Unit.
OBTAIN permission to enter the airspace,
LISTEN out on the appropriate ATC frequency.
OBEY instructions issued by ATC.
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Old 28th Dec 2014, 21:31
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Yes a clearance is required.

Airspace class - Wikipedia, the free encyclopedia
Thanks Vortex,


Sounds like a good mnemonic, regardless of airspace
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Old 29th Dec 2014, 06:06
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I work in class C space myself but I feel like you guys are in the wrong here.

Class D space doesn't mean that ATCOs should just give traffic information and hope for the best. A controllers responsibility regardless of airspace classification is to aviod collision and seperate traffic as long as neccesary. If shit hits the fan, 98% of the time the controller will be held responsible for the situation. So you can't really bash a controller for using the airspace wrong. You can always ask about the situation and have a constructive conversation about it, you should however in this situation (the way I've understood it) not call and bash him/her for using the airspace in a faulty manner.
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Old 29th Dec 2014, 06:55
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I think you are wrong. If it's a Class D zone, then the Class D rules should apply. The controller should not arbitrarily decide he is going to apply Class C rules.
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