Lateral flexibility around CLN

[bookworm]

10 days ago I was departing Cambridge via CLN and SASKI towards Brussels in a light twin at FL70. (Frequencies after Stansted Director were 121.22 and 135.42) It was quite convective, and with hindsight I could have been rather more circumspect in my weather avoidance.

It would be useful to know how much flexibility there is to approve significant deviations north and south on that routing within the LTMA at that low level. Am I hemmed in by a constant stream of arrivals and departures passing me, or am I the only aircraft around at that level with a reasonable expectation of being able to ask for substantial (say 15 mile) deviations around weather? I'm aware that I run out of controlled airspace to the north and the Shoeburyness ranges are to the south, but is there likely to be significant conflicting traffic?

Thanks

[eyeinthesky]

The short answer: there is plenty of lateral room, so ask.

Slightly longer answer:

There is almost certainly NO conflicting traffic once you are past CLN, and even before CLN the chances are that the arrivals into ABBOT are well above you. If you need to deviate for weather, then ask in plenty of time, and ATC will do their best to accommodate you. We would rather do that than have you messing up the place by falling from the middle of a CB in several pieces! As for leaving CAS, we will advise you of that and downgrade the service, but again that is probably the least of your worries. If you HAVE to go into D138/D138A and they are active, we do have the means to contact them and get them to stop firing in an emergency, but it is probably wise to plan your wx avoidance in the other direction

Also, bear in mind that you can fly CLN-COA at up to FL 110 if that helps.

[Widger]

As for leaving CAS, we will advise you of that and downgrade the service

Are you sure you are allowed to do that? Leading Question!

[rodan]

If an aircraft leaves controlled airspace, you have no choice but to change the service. Or am I missing something?

[bookworm]

Thank you eyeinthesky, that's just the sort of guidance I was after.

If I plan via CLN and I end up having to go south of D138/D138A via, say, SND, before turning for COA, does that cause you a lot of extra coordination work or can that be accommodated relatively easily? Would that be a reasonable routing at FL70 if there were no holding at ABBOT? Via SND seems to be the usual routing when EGSC DET DVR is filed, but that seems to be with 118.82 rather than 121.22. Just trying to get a feel for how much grief such requests cause...

Are you sure you are allowed to do that? Leading Question!

I was presuming that the deviation would be initiated by the pilot.

To be honest, my main concern with that as a pilot is not the service (RIS?) offered for the short time outside CAS, but rather staying on the frequency so that I can reenter CAS when required, without having to go through London Info to coordinate the rejoining clearance while battling both weather and CAS boundaries.

[5milesbaby]

Traffic levels are capped in severe instances of weather avoidance so the extra co-ordination you speak of can be done. Remember you are under a radar control service in Class A airspace so regardless we still have to provide minimum separation, likewise as a pilot you are responsible for you and your aircrafts safety, so we understand that avoiding weather is necessary. We don't like it but we will do what it takes when we need to. I know we are nothing compared to American weather systems, but you should have seen the avoidance two weeks ago. None of the Dover sectors traffic left UK FIR via the Dover sector although they were all in contact with them, and a DLH LL inbound via Clacton sector had to be brought south through DVR as he would not descend otherwise!

As for being allowed to downgrade a service if an aircraft leaves CAS, then we HAVE to do that as you cannot provide a Radar Control Service outside CAS. I wouldn't even provide a RAS as the turns given could very possibly take you back into the weather, best you sort yourselves out from the traffic information I give.

[bookworm]

I know we are nothing compared to American weather systems, but you should have seen the avoidance two weeks ago. None of the Dover sectors traffic left UK FIR via the Dover sector although they were all in contact with them, and a DLH LL inbound via Clacton sector had to be brought south through DVR as he would not descend otherwise!

Which day was that 5mb?

[eyeinthesky]

As I said before, we will do anything we can to help you. However, your question about going via SND is a little more complex. On your original route via CLN towards COA you are remaining in effectively the same sector airspace (the group known as East). So they are able to cope with all the vagaries of your route with just verbal coordination if they are split (more often than not they are all on one sector anyway).

If you go on the other route towards DET then you are crossing across several sectors, and you may well be close to the traffic for LL. Bear in mind that within 20nm of DET at the levels you are talking about there are three or more different sectors.
Also, as you route southbound you will be changing from TC North to TC South, who sit on opposite sides of the room. Thus coordination is more difficult, but not impossible.

If you take a look at the airways chart for that area and draw a line from EGMH to EGMC to LAM, then a good rule of thumb would be that if you remain East of that line then your weather avoidance can generally be handled easily (although you will be beneath CAS at FL70 once SE of EGMC), and to the West of it it gets more complex.

If you want to go via DET, then you would be better to file DET-DVR-KOK and then the plan will be easier to amend and the CAS will be down to a lower level.

Ref downgrading the service:

I meant that if your decision to take a route around weather will take you outside CAS temporarily then we are obliged to downgrade the service to RIS/RAS until you rejoin. If you are going to be outside CAS for a long time (eg SND-COA at FL70) then you might well find that controller workload/proactiveness/general apathy might well mean that they are unable to offer a service and will ask you to contact London Info and then get a new joining clearance.

All in all, I suggest you go via CLN and avoid to the East if you need to!!

EDITED: to correct a spelling mistake, but also to put EGMH in instead of EGMC twice!

[bookworm]

Again eyeinthesky, that is a very helpful level of explanation for practical purposes. Thanks for taking the time to set it out.

[5milesbaby]

bookworm, around the time you had your avoidance I worked about 6 shifts where we had wx avoidance going on, it wasn't the best of cycles!