Changes to the VMC Minima in Class D Airspace

[whowhenwhy]

Anyone had any thoughts on the change back to the old clear of cloud with surface in sight minima in class D? Not sure that it changes much from my perspective other than less requests for SVFR. Just not great timing with everything else that is going on in the world...?

[2 sheds]

Legalises what many are doing anyhoo, I suspect! And perfectly reasonable in controlled airspace.

2 s

[whowhenwhy]

Legalises what many are doing anyhoo, I suspect!

2 s
Sadly, I suspect you're right but was it because they didn't know better or deliberate action...? Rhetorical question and somewhat of a moot point now...

[Jim59]

Sadly, I suspect you're right but was it because they didn't know better or deliberate action...?

How is a light aircraft pilot supposed to measure the vertical distance to cloud above him/her reasonably accurately? It's always been guesswork.

[whowhenwhy]

How is a light aircraft pilot supposed to measure the vertical distance to cloud above him/her reasonably accurately? It's always been guesswork.

It's supposed to be educated guesswork informed by training and discussion with instructors and more experienced/qualified pilots.

[2 sheds]

Plus - we are talking about Class D - the current met report on ATIS or volmet.

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[whowhenwhy]

Plus - we are talking about Class D - the current met report on ATIS or volmet.

2 s
For flight within the ATZ and for take offs and landing (where met is officially reported) but otherwise it's pilot interpretation.

[2 sheds]

but otherwise it's pilot interpretation.
That's what we were talking about - the pilot determining how to remain 1,000 ft vertically from cloud when necessary - and the current met report can obviously assist in that assessment.

2 s

[whowhenwhy]

Ah, understood and agreed

[Nimmer]

And so much easier!!!

[jmmoric]

Haven't heard about it, but I suspect it's the minima in class D airspace in a control zone? A can give a few considerations to reducing it in the control zone at least.

From the perspective that no separation between normal VFR and IFR is provided, hence it's see and avoid, it'll bring up some issues.

When you provide traffic information to a VFR, and he stays the required distance from clouds, it'll give both the IFR and VFR ample time to aquire each other then the IFR comes dumping out of the clouds... if the VFR can linger around right below the clouds, that option is removed.

Hence when you get closer to the clouds, by requesting special VFR, ATC will make sure you're separated from other special VFR and IFR flights.

With todays requirements of transponders, it may not be as necessary, since an IFR flight are able to "see" a VFR flight before dumping onto him. And further you could argue that keeping VFR flights from the path of inbound and outbound IFR flights should be sufficient. Furthermore that ATC has an obligation to "avoid collision" between aircraft, so eventhough no separation is required, we may end up in a sticky situation, with the lawyers, if aircrafts collide after being only given traffic information and nothing else.

[2 sheds]

jmm
A rather confused and confusing comment, I thought. Whether operating with or without surveillance equipment, ATC is not going to deliberately descend an IFR flight to the same level as a VFR flight without a mile or two of safe distance between them, plus of course, timely traffic information. At least, I hope that is how you operate. Of course it will have to be borne in mind that the VFR, if slow, may be flying only just below the cloudbase and the aircraft may only have each other in sight fairly late. But as discussed earlier, that is probably how some of them are flying at the moment! I don't follow how you end up with the closing melodramatic scenario.

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[jmmoric]

jmm
....
2 s

That's how we all operate? But yes, the end comment was probably a bit melodramatic.

I was merely commenting on the removal of distance to cloud for VFR flights and how it could affect see and avoid.... nothing else. (In a control zone)

How VFR pilots handle it, is not for me to judge, but I expect them to adhere to regulation.

[NorthSouth]

I've never flown in any control zone in the UK where ATC doesn't apply minimum vertical separation of 1000ft between IFRs and VFRs below them. Hence the "IFR dumping out of the clouds" scenario is impossible.

[2 sheds]

NorthSouth
In essence you may be sort-of correct but you/we are talking about Class D airspace where separation as such is not applicable between IFR and VFR flights and, with respect, it is misleading if you use that term. Having said that, many units will apply a maximum level restriction so that the VFRs are a known quantity and need only be taken into account when an IFR is climbing or descending through that level band or to obviate the need for traffic information where avoiding action is impractical, for example a VFR departure and an IFR in a holding pattern overhead the aerodrome. However, there is no authority for the application of 1,000 ft as such in those circumstances (unless there is a WT interaction), but neither is there any guarantee of the VFR pilot's height keeping accuracy! It always surprises me though that there seems to be little reaction from the light aviation elements that such restrictions are not cancelled promptly when no longer required for safety. The intention of establishment of Class D airspece is that VFR flights should be free to operate up to the maximum level, albeit with ATC clearance and relevant traffic information.

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[2 sheds]

He didn't mention it, but the OP was referring to the UK.

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[whowhenwhy]

He didn't mention it, but the OP was referring to the UK.

2 s
Indeed I was 2sheds and you're spot on in your assessment

[jmmoric]

...The intention of establishment of Class D airspece is that VFR flights should be free to operate up to the maximum level, albeit with ATC clearance and relevant traffic information....

That would be the UK interpretation then, cause ICAO says otherwise?

[2 sheds]

Quote:
Originally Posted by 2 sheds View Post (https://www.pprune.org/atc-issues/637636-changes-vmc-minima-class-d-airspace.html#post10969160)
...The intention of establishment of Class D airspece is that VFR flights should be free to operate up to the maximum level, albeit with ATC clearance and relevant traffic information....

That would be the UK interpretation then, cause ICAO says otherwise?

No.
What are you suggesting that ICAO "says otherwise"? If you could quote references, it would be useful.

2 s

[jmmoric]

No.
What are you suggesting that ICAO "says otherwise"? If you could quote references, it would be useful.

2 s

Maybe I missed the point, but the VMC minima is the same for all controlled airspaces, so in that respect class D is no different from any of the other, except you can ask for Special VFR in control zones. It's not supposed to act as a "controlled class G" when it comes to VMC minima.

So besides the ability of the pilots to actually do as Annex 2 states, which I see as a training issue. I don't see any reason for removing this minima... unless you take more responsibility from the pilots by providing separation between more or less all flights since, as stated earlier, you remove the ability for aircraft to "aquire" each other is sufficient time to avoid each other.

[2 sheds]

jmm
You are mixing up two topics of the same general subject - a variation of the Class D VFR minima in the UK (as highlighted by the OP) and the common practice of ATC imposing a level restriction to VFR flights in Class D airspace. As regards the UK's imminent reversion to its pre-EU practice of permitting low-speed VFR flights to fly clear of cloud rather than 1,000ft below cloud, this is perfectly reasonable and practical as it avoids them being obliged to fly at low level for no good reason and we are not in the habit of descending IFR flights on top of them whatever the current rules may be! As regards VFR versus VFR, there is still the in-flight visibility requirement plus, commonly, specific routeings to minimise conflictions.

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[whowhenwhy]

Therein lies the key though 2 sheds. Clear of cloud works in the UK because we ask our ATCOs to go beyond what ICAO requires of them in class D airspace by applying what looks like class C rules. Of course, as you pointed out earlier, we don't call this separation...

[2 sheds]

Hi WWW - I would not say that UK ATCOs are asked to go beyond the ICAO requirements because, in addition to the procedures for the class of airspace, the requirement is to prevent collisions. I understand your reference to "look(ing) like class C rules" though, hence my earlier point about prompt derestriction and use of, for example, a safe one or two miles only (e.g.diverging with no WT consideration) plus appropriate traffic information. And it's not separation!

Cheers
2 s

[whowhenwhy]

2S :ok::ok:

[jmmoric]

jmm
You are mixing up two topics of the same general subject - a variation of the Class D VFR minima in the UK (as highlighted by the OP) and the common practice of ATC imposing a level restriction to VFR flights in Class D airspace. As regards the UK's imminent reversion to its pre-EU practice of permitting low-speed VFR flights to fly clear of cloud rather than 1,000ft below cloud, this is perfectly reasonable and practical as it avoids them being obliged to fly at low level for no good reason and we are not in the habit of descending IFR flights on top of them whatever the current rules may be! As regards VFR versus VFR, there is still the in-flight visibility requirement plus, commonly, specific routeings to minimise conflictions.
2 s

You kind of brought in the level restriction in your comment, so yes, I misunderstood it, I admit that.

EU was/is merely following ICAO in this matter. And I'm kind of weighing for and against more separation to clouds versus separation to terrain, and I'm not sure which one I like more.... if allowing clear of clouds, you can fly in at 500 ft with a solid overcast in 500 ft, the only difference being not having to request Special VFR which again removes the requirement for separation against other traffic. From a pilots perspective, having done it a couple of times, it's way more comforting approaching an airport in poor visibility/low clouds, knowing you only have to navigate and not look for traffic. From a controllers point of view, both tower and approach, it requires a bit more work and time, but it's definately easy (and our control zone is huge.... with poor radar coverage except on the extended centrelines).

I do agree, that D airspace should be limitless for VFR flights, otherwise you may just as well establish a more restrictive airspace.

[2 sheds]

if allowing clear of clouds, you can fly in at 500 ft with a solid overcast in 500 ft

No - UK will still have visibility and cloud limits on issue of VFR clearances to and from the aerodrome.

2 s