Split/Bandbox of en-route sectors in Europe

[windneckin]

I have heard a few people saying that en-route sectors in countries like Spain or France are always open regardless of the level of traffic. No concept of bandboxing sectors when it is quiet and splitting them when it gets busier to optimise resources. At the same time, I have heard sectors are split/bandboxed in at Maastricht. Is that the case? We do quite a bit of splitting/bandboxing in my neck of the woods.

I would appreciate if somebody could enlighten me about that point.

Thank you very much!

[Nock]

Well that only means that a few people are wrong!
In France, sectors are split or collapsed depending on the traffic. Of course they are not always opened (otherwise the job would be quite boring)! I would really like to know why people told you that kind of things!

cheers
Nock

[andrijander]

I do not know how they do it elsewhere but yes, in Maastricht freq's/sectors can be bandboxed (coupled, as we call it) and sectors (de)collapsed (a.w.c.i.). It would make for a very unproductive unit if, say, during night ops we needed the same amount of staff as during daytime with 1/20th of the traffic.

Rgrds,
A.

[BrATCO]

The number of flights per hour is not the only reason to chose band-boxing/splitting sectors. ("group/de-group", AWCI)

The nature of flows is another one.
If the expected traffic is due to be made of vertical flows (departures from/arrivals to London, Brussels, Paris, ...) then the splitting scheme will not be the same as if the traffic is due to be leveled on a given sector (several flows to be crossed at the same level).
Depending on the hours of the day, a mix of configurations is used and can be changed up to several times per hour.
ATFM can be a factor too : if we need a protection (a SLAP, Slot Allocation Procedure, provided by CFMU) on a sector, then said sector must be split. Don't know wether this is a French or a European rule.

Many other reasons (CBs, turbulence, technical, military activity,...) must be taken into account.

We (the French) couldn't deal with more than 12.000 flights per day without a bit of flexibility...
I reckon France is neither more, nor less flexible than Spain, MUAC, or any other ANSP in Europe.

[windneckin]

Thanks a lot for your replies!

Yes, I understand that sectors get bandboxed/combined at night but if, I remember correctly, the whole discussion that prompted me to post on here started while talking about the existence or not of Traffic Load Prediction Devices in area control centres around Europe that could give you a 24-hour dynamic picture of how the traffic is going to be and what kind of traffic you are going to have (outbounds, inbounds, crossing, ...).

[BrATCO]

A 24 hours Traffic Load Prediction Device ?

Wow ! That would be impressive ! :eek:

Would this device predict CBs, turbulence, unavailability of a runway (or of an ILS), or ash clouds, snow, passengers showing late, technical problems before or after departure... executive jets filing their FPL only 2 hours before departure ? :}

I usually don't know the kind of clearance I will give more than 10 minutes in advance... :sad:

More seriously, France already used such devices 20 years ago :
-PREVI was used for slot allocation and real time statistics.
-IMAGE was a real time image of the actual traffic.
-COURAGE was an help to predict the traffic and implement flow management procedures (more than 24 hours before)
-PRESAGE is a mix of all this and looks pretty much like the CHMIs we can see in any FMP in Europe.
We still use PREVI and CHMI on parallel.

All these devices existed in France before CFMU was implemented (late 80's, early 90'... last century !). :ok:

[WetFeet]

I retired a few years ago but when I left TLPD had been in use for some considerable time at UK enroute centres.

[andrijander]

Well I usually don't know what kind of clearance I'm gonna give until I speak :}

Yes, as BrATCO pointed out they do exist. We also use CFMU's CHMI but, albeit you could look so many hours ahead, you need to know that isn't it, no one can predict the future. When looking at which sector configurations we will play out tactically, we analyze traffic with our flow unit and we almost never look further than 3 hours, as what we get tends to be unrealistic (unless it is one of those days when things play out like the computer predicted...which is, well, T.B.H. never).

In a way is like taking photos of waves in the ocean. Next time you look it has already changed.

[windneckin]

guys guys... the key is 24-hour DYNAMIC picture of the situation....

it takes into account flight planned flights, airborne times, taxiing times and clearly the weather is implicitly factored in. Obviously, we wouldn't be using that to predict the traffic 10 hours down the line... that would be plain stupid.

But I can tell you that in UK area centres it gives a fairly good picture of what's going to happen in the next 30-45min... and if you want to know what's going to happen in 1:30-2hr ... you just wait and have a look at it again 60min later :ok:

[BrATCO]

If I want to know what's going to happen in 30 mins (and I've got time to think about it), I just have to de-zoom my radar image : it's dynamic.

If the CHMI says I will suffer a load and there's not much overlit traffic on my screen, then the traffic I still don't see will come either from UK, Belgium, Shannon, Shanwick, Spain, Bordeaux ACC or Paris ACC, depending on the sector I work on. We also have a dynamic list of scheduled flights for the next 30mins on the control position. :8

No real need to see them when they're not yet airborne. I reckon too much precision in prediction only gives you a very precise false
information.

PS : How do you say "gadget" in English ? :}

[windneckin]

Interesting discussion!

Well, the controller is not the one looking at the TLPD, rather the supervisor to allocate staffing appropriately.

Where I work, that "gadget" is used to schedule the split/bandboxing of sectors, allocation of breaks, rostering of sectors when controllers are valid on more than one group of sectors, and when sectors will be able to be bandboxed for the rest of the day.

That's not to say that we don't have unexpected events, that's the nature of ATC, and that's why controllers go on their breaks with phones so that they can be reached if the need arises :)

[BrATCO]

Well, let's say a "useful gadget", then.:)

The procedures you describe are pretty much the same as the ones I could have described, we just don't use the "moving" part of the prediction : we rely on numbers. Works fine when done properly.

Precision : I de-zoom my radar image only when/if the supervisor has warned me, after he has made the analysis (he's got plenty of time for this !).

Our rosters have bbecome quite rigid down here : since last year's mess, they don't change anymore but, in regard of the predicted traffic, we still have pauses. In the control room, or in the room next to it, so no need for phones.(in fact, we've got three of them, but don't use them anymore)

We are all qualified on the 40ish sectors of our center : 14 geographic sectors cut vertically in slices. As you see, we don't miss staffing flexibility either.
I guess same job, same reason, same result... management makes the difference...:oh:

Question : does your TLPD have a "rewind" button ? Is there a possibility to get back to a part of the prediction that could have been missed for any reason ? I mean the part that says what will happen in 20 mins instead of 40, for exemple (useless, I know... just curious)

[windneckin]

I don't know for sure if there is a rewind button but I suppose we keep some sort of record of the TLPD readings for legal reasons in case split/bandboxing needs to be investigated. You can definitely see an hour or so back on the display.

Here is a link to how that display looks:

http://www.eurocontrol.int/dmean/gallery/content/public/Best%20Practices/tcm/NATS%20TCM%20draft%203.pdf

[5milesbaby]

Could the original rumour have come from working to rule BrATCO? I'm sure a while back for a few weeks Brest/Paris opened all the sectors during the day regardless of traffic loadings just to make a point. It was the same time that we (London) got told to stop sending traffic through Etrat/Veule on direct routings beyond those points as we would enter another sector (and not to do with the La Manche resectoring either).

Our TLPD is blocked into 15 minute segments and has different colours for different flights, ie red is actually in the sector, orange is airborne in another FIR, pink I think is airborne in the UK FIR, green is pending live time without flow restriction (you get the idea)...... It is not a very good "gadget" IMHO!!!

[Arkady]

On the NATS TLPD red is generated from radar derived information from a UK source, pink is derived from other radar sources and as such they are pretty reliable. Orange(?), I think you mean gold, are aircraft subject to flow restrictions and not yet airbourne and they tend to be fairly accurate as well. Green you have right, pending live with no flow restriction and these tend to be very changable. The UK TLPD is an accurate reflection of the information that is entered into it. The quality of that information though..............:rolleyes:

[BrATCO]

On our homemade system, we could chose the colours in regard of the flows.
This system was used mostly to show pretty images to visitors and journos. They were very impressed !:}
Don't know if the image is still available as I haven't seen it for years. As I said, we use numbers.

5Miles, you must be right : there's no smoke without a fire somewhere...

Not only a point to be made : also the only way we could work when our management supressed any flexibility in the rosters, after a bash in the press followed by an over-reaction from the govnmt...:rolleyes:
Not only Paris and Brest : Bordeaux, Marseille and Reims had the same problem. Local managements made the difference.
But that was one year ago.

As to SITET, VEULE, the (rotten) La Manche "new" sectorisation made that the sector you had as an interface could not take any decision for the following sector (because sectors were split all day long, due to lack of flexibility).
Not easy to explain... that's because of the interface with Paris, Bordeaux, Reims and Brest (15ish steady flows plus some vertical flows in a 40NM radius). A direct given at the wrong time can result in a mess with no advice for the following sector.
Even today, these sectors are not easy to control, since the new "La Manche". But it should change (back to previous, more secure, more efficient procedures) when we get two frequencies.
I'd like to add our management hasn't yet (and probably will never) find flexibility again, but I reckon you (and pilots) don't feel it too much anymore.
I happen to phone S1/S18 to propose directs in order to help.;)

Retrospective fear :
French ATC suffered another attack from the press last month. :eek:
Our Transportation Minister had a good reflex in defending us this time. :D
So this summer should be smoother than last one...:cool:

[5milesbaby]

Then we must have spoken BrATCO, I'm one of the ones delivering the mess from S18 :} Just hope that our "home made system" doesn't hinder that further when introduced later in the year, your summer may be easier, ours will be "interesting" :uhoh: