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Re: VMC minima in class D airspace... CAA consultation

PostPosted:Tue May 14, 2019 6:14 pm
by derekf
AlanM wrote:@PaulB - yep as per post #4 on this page....

https://cidca.aero/CHttpHandler.ashx?id=115009&p=0

It talks about Self declared weather and tbh the ATCOs think it works much easier than before. @derekf - is it easier for you as a customer??

That's an interesting question
In all honesty I can't say I've found it easier, but equally I definitely haven't found it any harder, although I've always been happy to just file IFR and if asked for my intentions before entering the one if below VFR I'd always just go IFR.
However having re-read the presentation (and yes I did go to the presentation at the club) I can see that there could be some benefits if not VFR and you don't want to or can't go IFR...
Now when I'd been flying something 2 tonnes I may have been even more interested until seeing the speed limit :lol: :lol: :lol:

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Thu May 23, 2019 3:24 pm
by Hutchy96
Quite simply, this would be disastrous for us here in Scotland with the weather that we have...

Below is what the FI at our airfield has submitted to the CAA, so I can't take any credit for it, but he has urged us all to read it and submit our own response. This proposal could really ruin GA flying for us

Question 1: Do you agree with the CAA’s assessment of typical weather conditions in the UK?

No. The data used consist of Met Office records of “cloud ceiling” at or below 3000ft amsl. But ‘cloud ceiling’ is defined in SERA as cloud covering more than half of the sky – equivalent to the METAR codes OVC and BKN. In practice, if there is SCT cloud (3 or 4 oktas) at or below 3000ft, and even in some circumstances with FEW at those levels, aircraft flying VFR transits will be flying at levels that keep them below all cloud. So the data used in the consultation document will be significantly under-estimating the frequency with which VFR transits will be affected by the proposed new rule. It should also be noted that SERA.5001 doesn’t require 1000ft vertical separation from the cloud ceiling or cloud base; it requires 1000ft separation from any cloud.

We also note that the prevalence of cloudbases lower than 3000ft is significantly greater in Central Scotland and Northern Ireland than other parts of the UK. The proposed changes will therefore have greater impact in those areas. Forcing more than 81% of current VFR transits to request a Special VFR clearance is in our view unacceptable for the reasons outlined below.


Question 2: Do you support the CAA’s preferred option and the associated assumptions?

We do not support the CAA’s preferred option, for the following reasons:

1. The high frequency of cloud below 3000ft in Scotland means that a very high proportion of current VFR transits will be forced to either (a) fly lower than they normally would, in order to maintain 1000ft vertical separation from cloud, or (b) request a Special VFR clearance. Pilots choosing to do the former will have less safety margin in the event of an engine failure and will be at higher risk of contravening the SERA rules on minimum heights. There is no acknowledgement of this safety disbenefit in the consultation document.

2. Pilots choosing to request a Special VFR clearance will then be subject to ATC separation from all IFR flights. In busy CTRs such as Edinburgh, Glasgow and Aberdeen this will create significant delays as controllers hold SVFR traffic at least 3nm away from approach/climbout paths, awaiting a gap to allow the SVFR traffic to cross. At Edinburgh in particular this is highly likely to involve lengthy periods when SVFR aircraft are orbiting awaiting onward clearance, with the potential for subsequent SVFR traffic having to be held further back. Typical SVFR traffic will take at least four minutes to make the 6nm crossing, during which time no IFR movements will be possible. The only possible outcome of that is that ATC will refuse all SVFR transit requests unless they can guarantee no impact on IFR arrivals or departures.

3. The reality, or VFR pilot expectation, of SVFR zone transit refusals will lead to many more VFR pilots choosing to route around the CTR. At Edinburgh this has serious safety implications. A route to the east of the CTR takes aircraft on a sea crossing of at least 8nm, during which they must remain below the Edinburgh CTA at 2500ft. This is insufficient altitude to glide to land in the event of an engine failure and increases the risk of vertical infringements of the Edinburgh CTA in a critical area under their main approach path. VFR traffic avoiding the CTR to the west would be forced to fly through a narrow corridor where again the base of controlled airspace is 2500ft and there are obstacles up to 1938ft and restricted areas further constraining traffic. Once again this is likely to increase the risk of vertical infringements of controlled airspace under Edinburgh’s approach paths and will also increase the risk of conflicts with other VFR traffic since aircraft avoiding the Glasgow CTR will also be in this area.

4. The consultation document asserts that increased vertical distance from cloud increases the efficacy of see and avoid in Class D airspace. This is highly debatable. Because aircraft currently flying VFR transits are in the vast majority of cases flying below all cloud, it is extremely rare for visual acquisition of conflicting traffic to be compromised by cloud between the two aircraft. We can see no basis for asserting that see and avoid will be improved under the proposed rule.


Question 3: Do you agree with the CAA analysis of the projected workload change for ATC units and the effectiveness of the proposed mitigation?

No. It is the requirement for separation of SVFR from IFR that is the principal driver of the increased controller workload, not separation of SVFR from SVFR. The proposed mitigation – removing the requirement to separate SVFR from SVFR – is insignificant by comparison because (in our experience) there is much more IFR traffic in CTRs than VFR. The proposed change will result in VFR traffic occupying the CTR for much longer than currently, and requiring large gaps between IFR arrivals/departures to transit over the airport, leading to multiple additional RT exchanges and a more complex relationship between Approach/Radar and Tower controllers for the handover of SVFR traffic. All of this will lead to increases in controller workload which we predict will inevitably result in many, perhaps all, SVFR transit requests being denied.


Question 4: Do you agree with the CAA analysis of the potential impact on the provision of non-IFR flight? Are there any additional factors you feel should be considered?

We submit that the consultation document does not adequately address the practical impacts of the proposed change in terms of what VFR pilots will choose to do and the safety implications of those choices. Nor does it consider the context of cost-cutting and personnel shortages in ATC. VFR transits through the Glasgow CTR have already been restricted for long periods due to ATC staff shortage and Edinburgh ATC already have in place a telephone advance booking system for VFR transits, which, if not used, can lead to delays in obtaining a clearance or even a refusal.

It is clear that the sole reason for this proposed rule change is so that the UK can demonstrate full compliance with SERA, which the document notes is “directly applicable EU law”. But the UK is leaving the EU. Surely, then, it is better to wait until we find out whether and under what terms the UK is leaving, before applying rule changes that may be irrelevant in a few months’ time?


Question 5: Do you agree with the CAA’s assessment of safety impact?

No. There is no mention of the impact on pilots who, knowing that if they ask for an SVFR clearance they will get either a refusal or lengthy delays, request a VFR transit and then fly much lower than they normally would in order to meet the 1000ft vertical separation from cloud requirement. This is particularly acute in the Glasgow and Edinburgh CTRs where the combination of high ground, obstacles and congested areas means there is only a very narrow altitude band between the normal maximum VFR clearance altitude and the minimum height for clearing obstacles and congested areas.


- Adam

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Thu May 23, 2019 4:14 pm
by Balliol
Adam that’s a cracking piece of work and echoes what I have responded to for my operation in a Class D zone. I hope the representative organisations take up similar well reasoned responses.

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 11:20 am
by Aeronca Alan
Twice, I feel I have carefully read though CAP 1779 and I'm still not quite sure I am understanding it correctly.

I am based at Cardiff Airport, inside a Class D CTR. As I understand it, from 13th September, when wanting to depart or arrive, if the cloud is such that I cannot keep 1,000' vertically and 1,500m horizontally away from it (whilst obeying other rules such as the 500' rule) then I will have to request a SVFR clearance. I don't think this, in practice, should be a problem as long as ATC are not over-zealous. At the moment, Cardiff ATC in effect, and rightly or wrongly (it's academic), separate VFR traffic from IFR traffic. I don't see what the difference will be if I am in receipt of a SVFR clearance. Is there a difference?

I'm afraid that if my interpretation is wrong then my days of flying from Cardiff are numbered.

(I note the excellent Scottish piece above. Cardiff is a somewhat quieter airport with less IFR traffic. CAP 1779 contains a load of utter nonsenses, such as the "see and avoid" safety benefits.)

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 11:31 am
by James Chan
In Class D, ATC should not normally separate VFR traffic and IFR traffic.
Traffic information is passed so that pilots can self separate visually.
But they should separate SVFR with IFR, SVFR with SVFR, and IFR with IFR.

In poorer visual conditions, SVFR clearances may be requested - we can't see that far, so how to take the steps needed to avoid?

This consultation deals with situations where SVFR and SVFR should not be separated, which is not really something I want for my type of flying and out of line with international (best) practice.

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 12:14 pm
by AlanM
It does kind of annoy me when people say “ATC at xxxxx separate IFR and VFR”.

There is a world of difference between “Separate” and “deconflict”. Separate suggests that people are using Standard Separation which has its own legal definition.

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 12:17 pm
by AlanM
James Chan wrote:In Class D, ATC should not normally separate VFR traffic and IFR traffic.
Traffic information is passed so that pilots can self separate visually.
But they should separate SVFR with IFR, SVFR with SVFR, and IFR with IFR.

In poorer visual conditions, SVFR clearances may be requested - we can't see that far, so how to take the steps needed to avoid?

This consultation deals with situations where SVFR and SVFR should not be separated, which is not really something I want for my type of flying and out of line with international (best) practice.


Totally agree. As an ATCO, not separating SVFR v SVFR makes life very easy!

It is also ridiculously dangerous to have light aircraft flying SVFR with see and avoid principles when the visibility is low, the cloud OVC011 and the top of the rudder up against the base. As James says, that is when you need separation.

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 12:28 pm
by Buzz53
Aeronca Alan wrote:I am based at Cardiff Airport, inside a Class D CTR

Maybe you didn't pickup from earlier in the thread that you won't be able to fly legally in the 1500 foot CTAs at either end if the cloud is 2500 or less. At least, unlike elsewhere, you do have 3000 ft CTAs to North and South so if you're happy to arrive/depart through those then you're OK.
Alan

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 12:42 pm
by James Chan
won't be able to fly legally in the 1500 foot CTAs at either end if the cloud is 2500 or less.


But you might, because you don't really know if the cloud just there is 2500 or less. It's a grey area. :D

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 1:24 pm
by Buzz53
We’ve been round this one before, without success I think. Everybody not wet behind the ears knows perfectly well what cloudbase is, especially when they are bumping on the bottom of it. You can mince your words and stick as many smileys on the end as you like but James, you and others are proposing that people get round this by just plain lying about their flight conditions while in controlled airspace and under surveillance, and just carrying on as before (except it’s worse than before because now everybody believes there will be no unseparated traffic less than 1000 ft from cloud). I note that the people making the suggestion appear to be instrument rated so won’t have to stoop to this. When it goes wrong (e.g. somebody MORs and there’s an investigation) who will be in the dock? It won’t be the ATCO or the Einsteins responsible for the proposed legislative changes for sure.
I remain astonished at the apparent apathy, or is it just lack of understanding (maybe on my part)?

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 1:28 pm
by Aeronca Alan
Maybe you didn't pickup from earlier in the thread that you won't be able to fly legally in the 1500 foot CTAs at either end if the cloud is 2500 or less. At least, unlike elsewhere, you do have 3000 ft CTAs to North and South so if you're happy to arrive/depart through those then you're OK.
Alan


I did miss that you raised this. Where does this come from? I don't see any mention of it in CAP1779.

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 1:37 pm
by James Chan
I remain astonished at the apparent apathy, or is it just lack of understanding (maybe on my part)?


You can keep remaining astonished because nobody really cares about this situation. People will care if there is an incident. ATC are supposed to give you traffic information. But if you cannot see it due to cloud, you say so and may ask for vectors to avoid. If you can see it then you say so and maintain visual separation.

You also squawk ALT where equipped, and others do the same so that any TCAS systems are alerted if you get too close.

You also maintain clear of cloud and ensure you have more than enough space to manoeuvre if you’re on a VFR clearance.

This is how the real world works.

Not some kind of legalistic "I must make sure I must give at least 1000ft and 1500m of spacing around every cloud above and below and in front of me" by continuously measuring all around you, in order to not get busted.

Nobody I know flies like this, ever.

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 1:51 pm
by Buzz53
Aeronca Alan wrote:I did miss that you raised this. Where does this come from? I don't see any mention of it in CAP1779.

Exactly, they don't even acknowledge the problem, deliberately or not who knows? CAP1779 deals with mitigating the consequences for changes to the definition of VMC in Class D but takes a rather narrow view. The assumption is that much of the former VFR traffic will now just become SFVR and life goes on as before. The mitigation is intended to avoid ATCO overload due to the increased numbers of SVR. It fails to mention that SVFR is not allowed in a CTA, only a CTR.
Alan

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 2:02 pm
by Aeronca Alan
It fails to mention that SVFR is not allowed in a CTA, only a CTR.


No, CAP 1779 clearly mentions that in 2.2 (and perhaps elsewhere).

I'm still trying to understand the bigger point you are making:
you won't be able to fly legally in the 1500 foot CTAs at either end if the cloud is 2500 or less.


AlanM (apparently an ATCO) seems to endorse your point so I'm guessing you're probably right, but what is the reference (or logic) for this?

Re: VMC minima in class D airspace... CAA consultation

PostPosted:Fri May 24, 2019 2:15 pm
by James Chan
Yet cloud base is measured at the aerodrome, which can have a very different elevation to where any other CTA is.

And clouds often don't have uniform base and coverage either.