UK Class D VFR exemption

SERA requires 1500mtrs horizontal and 1000ft vertical separation from cloud in class D airspace.

The CAA are allowing aircraft in the UK to have less distance from cloud in Class D, if they are clear of cloud and insight of the surface.

I do not think that Part-SERA provides for national peculiarities except where this is explicitly stated.
I guess that UK CAA being UK, they are not all that interested in what a European set of rules like Part-SERA actually says, but sometimes they find out that SERA does not have it right, and they publish an Official Record like this one, to make sure no-one in the UK will follow the silly EU/EASA rules.
I have seen this 4 or 5 times now.
For the record, I think that the UK might well have most of it right. But the point is not just what is right, but that the UK CAA makes it rather obvious that they only regard EASA/SERA as guidance at most, not as an obligatory law which rules all over the EU/EASA-land.
I know at least one instance where an EASA official was hopping mad when he was told about this (it was not by me!).

They have no legal basis for this. Article 14(4) of the Basic Regulation states

Member States may grant exemptions from the substantive requirements laid down in this Regulation and its implementing rules in the event of unforeseen urgent operational circumstances or oper­ ational needs of a limited duration, provided the level of safety is not adversely affected. The Agency, the Commission and the other Member States shall be notified of any such exemptions as soon as they become repetitive or where they are granted for periods of more than two months.

So what are the “unforseen urgent operational circumstances/needs”? And what about “limited duration”?

Also, I doubt if this is a good idea as there is no VFR-IFR separation in class D.

I don’t wish to be accused of defending the UK CAA, but it has notified this exemption under Article 14(6) of the BR:

6. Where an equivalent level of protection to that attained by the application of the rules implementing this Regulation can be achieved by other means, Member States may, without discrimination on grounds of nationality, grant an approval derogating from those implementing rules.
In such cases, the Member State concerned shall notify the Agency and the Commission that it intends to grant such an approval, and shall give reasons demonstrating the need to derogate from the rule concerned, as well as the conditions laid down to ensure that an equivalent level of protection is achieved

…presumably on the basis that VFR clear of cloud under radar control in Class D has never been a problem, and that the SERA.5001 rule is half-baked homicidal euro-lunacy (in that by closing large volumes of Class D to VFR traffic, it would funnel that traffic into busy uncontrolled pinch-points such as the one between Luton and Stansted). But what can we expect from the organisation which tried to extinguish the IMC rating?

There are two opposing considerations about required vertical distance from cloud in class D. One is that because there is no VFR-IFR separation, there is a need for a buffer below cloud to prevent descending IFR traffic from hitting a VFR in the head because they would not have time to see and avoid each other. This is the SERA.5001 rationale. The other is that by “blocking” 1000 ft below a ceiling of say 1700 ft, quite typical in the UK I would guess, large volumes of class D is in effect closed to VFR, forcing VFR to stay away or navigate at low levels between towns and between each other. Special VFR is available to solve that problem, but that reduces capacity dramatically. SERA.5001 ignores this problem and hence the UK move.

AFAIR, in the US the requirement in control zones is or used to be only 500 ft below cloud. It could be seen as a compromise, and I believe it makes sense.

At my airfield, this very rule is the only rule that I have been told (repeatedly) by examiners they would not fail, or even criticize, an applicant for busting “as long as the applicant exhibits some respect for clouds and do not go very close underneath” or something like that. I have always found that interesting and a testament that SERA.5001 is indeed problematic. TWR also goes along: if there is around BKN017 (not rare at all) there is practically no way to fly VFR in the CTR according to SERA.5001, but asking for special VFR will warrant a pause on the frequency while you can almost hear the controllers looking bewildered at each other wondering what that will do to capacity (and tower workload).

Now I come to think about it, I guess the difference from UK is only that here we do not bother to tell anyone that SERA.5001 is a problem and we are effectually bending it to make things work.

There are two opposing considerations about required vertical distance from cloud in class D. One is that because there is no VFR-IFR separation, there is a need for a buffer below cloud to prevent descending IFR traffic from hitting a VFR in the head because they would not have time to see and avoid each other. This is the SERA.5001 rationale.

I’m surely missing something, because I simply don’t understand this rationale. Whenever, say, Prestwick or Essex Radar gives me a VFR clearance to transit their CTR, they check my radio and Mode C and put me under radar control at the boundary. From that point, if the controller says “sh1t”, I have to jump on the shovel. If she sees a potential conflict she tells me to hang a left turn, or stay put, or (all too often) to put some more dead dinosaurs into the fire. I can’t imagine a situation where she would drop an A380 on top of me out of a fluffy white cloud just to see if I’m paying attention.

Jacko wrote:

I can’t imagine a situation where she would drop an A380 on top of me out of a fluffy white cloud just to see if I’m paying attention.

If she is nice, she won’t do it for that, but maybe because she forgot about you, being busy separating IFR from IFR, which is her main responsibility. If she happened to drop that A380 on top of you straight out of the blue, she would always say that it was not her responsibility because you should have seen and avoided. You might not think that was fair if you were legally flying very close to the clouds.
Besides, there is no obligation to carry a transponder in class D airspace so the rules have to work for those without a transponder too.
That is the rationale as I see it. But I also see that requiring 1000 ft below clouds does not always seem to be practical.

Airborne_Again wrote:

So what are the “unforseen urgent operational circumstances/needs”? And what about “limited duration”?

Also, I doubt if this is a good idea as there is no VFR-IFR separation in class D.

The UK has always used class D around airports, and has always had a rule “< 3000ft, <140kt, clear of clouds” for them.

To change this to the SERA rules would effectively prohibit VFR to most airports in the UK for about 350 days a year otherwise which would be a severe and intolerable constraint for most of GA (and cause serious capacity issues with everyone asking for SVFR clearances). For instance, at EGNS, there is almost always a cloud layer at 1500 feet or below, usually just a FEW layer on a VFR day, but it would necessitate having to fly in the zone at 500 feet which is a lot less safe than flying clear of cloud when there is a FEW layer – especially since whenever you enter the zone you are given radar control service.

It was probably an “unforseen” circumstance that SERA would impose such draconian and dunderheaded cloud clearances, and 100 years is still a “limited duration”! To implement SERA without completely gimping VFR access to class D would require a huge redesign of all UK airspace, a project that would take years. (It’s probably needed, but in the meantime keeping the eminently sensible rules the UK have always had about cloud clearances is probably the most pragmatic approach. There is also a similar exemption to SERA for minimum altitudes, otherwise glider ridge soaring would have been banned).

That generally there are not lists of airprox incidents in class D airspace shows the system is actually working.

Jacko is right….it ain’t broke….