Primarily for general aviation discussion, but other aviation topics are also welcome.
#1688633
As promised (threatened?) I have analysed all of the 2018 METARs from Gatwick during the daytime (0900-1800 - modelling the actual Redhill opening hours are a little too complex for a quick Excel hack!) and produced the following:













IFRSVFRVFR
Jan14%21%65%
Feb5%11%84%
Mar5%27%68%
Apr8%21%71%
May1%11%88%
Jun1%8%91%
Jul2%2%96%
Aug2%6%92%
Sep0%6%94%
Oct6%12%82%
Nov11%18%72%
Dec8%22%69%
Grand Total5%14%81%


The previously shared figures aren't entirely accurate for March 2019 - my METAR parser didn't exclude overnight METARs, and was a little pessimistic in converting "CAVOK" into "IFR"! These figures should be correct, however, and as you can see, not-flyable-at-Redhill SVFR conditions frequently represent more than a fifth of the flying days in any month, and are significant (>5%) of almost the entire year.
#1688696
Currently VFR flights in Class D are just given traffic information on IFR to self separate - what would be the situation with SVFR vs IFR under the new proposal? [I can go and research but if anyone can quickly answer much appreciated]
#1688704
Balliol wrote:Currently VFR flights in Class D are just given traffic information on IFR to self separate

In theory, yes, but in practice I have countless personal examples where I've been vectored or given routing instructions that go way beyond 'Are you visual with the traffic, if so, pass above and behind them' type separation assistance.
#1688708
At first glance, this appears to be a significant increase in complexity with large room for misunderstanding by many parties.

I don't know what problem it's trying to solve?

If conditions are not suitable for VFR flight, them I may elect for SVFR or IFR.
If I go SVFR or IFR, then I expect to be separated from other SVFR and IFR - this is in-line with ICAO.

It's a no brainer for me really.

Changing this seems to be like layering multiple levels of UK-FIS on top of ICAO surveillance-FIS all over again?
T67M liked this
#1688709
The issue is the application of separation - perhaps an ATCO on here can explain the realities of having to do that? I currently operate out of a Class D zone with a standard VFR departure route in and out and we are just at a set altitude below heavy inbounds and out bounds and see and avoid with traffic info provided. If the ATCOs had to separate us on a SVFR clearance (a significant % of the time with cloud base) I don’t know exactly what implications that would have.
#1688710
The problem is the issue of separating SVFR traffic from IFR in Class D airspace.
At present, given the SERA exemption, one can fly VFR most of the time in the Class D CTR below 3000'. Separation is not required from IFR aircraft and thus one can orbit in one's Cherokee on base leg waiting for a gap in the arriving stream of IFR Airbus and Dash 8s for an opportunity to proceed to final and land.
If we now have to operate SVFR when the cloudbase is below say 2300' (we do need a sensible separation from terrain around the airport) orbiting on base leg is no longer possible as 3nm separation from IFR traffic is required. Thus one ends up holding a distance from the field and not being able to take advantage of a gap in IFR inbounds. Then the Approach controller has to manufacture a longer gap to allow one to land, all much more difficult than the current procedure.
Hawkwind, flybymike liked this
#1688711
I'm guessing the heavies are operating IFR.

But this consultation isn't addressing the separation requirements between SVFR<--> IFR.
It's about addressing separation requirements between SVFR <--> SVFR.

?
AlanM liked this
#1688742
Balliol wrote:AlanM yes but the predominate traffic in the zone is IFR (scenario similar to tailbob)


Are there not SVFR/VFR routes published?

Also, as I said at the start, do what we do here with full SERA rules. Only impose flight rules in the ATZ based on the METAR for inbounds (and outbounds).

(PS what is the airfield that you mention)
#1688743
AlanM wrote:“I am Unable to issue a VFR clearance - what are your intentions?”

Because we, as ATCOs have no knowledge of your ability/qualifications to fly SVFR or IFR (assuming you have filed VFR)


As far as I recall, the conversation then goes:

"Erm, say again, G-CD"
"G-CD, is there something special I can do for you?"
"Oh, yeah, erm, request SVFR zone transit, G-CD"
AlanM, G-BLEW, Tall_Guy_In_a_PA28 and 3 others liked this
#1688747
Balliol wrote:AlanM yes but the predominate traffic in the zone is IFR (scenario similar to tailbob)


Which is why the CAA's proposal is daft. The issue (other than for airfields with an ATZ embedded in the class D) is not the separation of transiting (S)VFR traffic from each other. It is the separation of transiting (S)VFR traffic from the IFR inbounds and outbounds that comprise most of the controller's business. Thus the exemption not only produces non-standardisation and complexity, but also fails to solve the main problem, which is the reluctance of ATC to allow SVFR into the zone when standard separation has to be provided from IFR.
James Chan, imperialsam liked this
#1688750
bookworm wrote:
Balliol wrote:AlanM yes but the predominate traffic in the zone is IFR (scenario similar to tailbob)


Which is why the CAA's proposal is daft.


Yep. In fact, in rubbish weather, when the visibility and cloudbase is lower it means you will no longer be separated from other ‘scud running’ traffic.

All very bizarre.

Someone should remind the CAA what the S in SERA means......
James Chan liked this