How far ahead can you plan?

[renard]

Last week, flying EGFF-EBBR, at about FL120 approaching Alvin, so not that long after take off, asked if we could make FL290 by CPT. We said yes, so cleared to FL290. Quite soon afterwards, told "at request of next sector, stop climb FL280", which we did.

When level at FL280, after about 3-4 minutes a plane flew across our track at FL 290 within a mile of us.

A few months earlier, coming back from EBBR, we had to descend before LAM. About 50 miles later, the same sort of thing happened. An aircraft flew right over the top of us.

My question is - the controller for the sector east of CPT, is their big picture so big that they could see that we would be causing a conflict, 80 miles or so before it happens, and before we are under their control, or is there some computer alert system.

I have heard of STACA, would this be a LTACA?

Thanks

[Heading 365]

Called changing your plan, the one crossing above might not have made the level it was supposed to therefore the request for a stop off, e.g EGCC departures for higher levels going south are supposed to be 310 50nm before MID, a lot don't make it. The next sector might not have been aware at the time that the intial co-ordination was done.

Did you get 290 after passing the traffic?

[renard]

We did get cleared climb FL290 once the traffic had passed us.

[Llamapoo]

Planning horizons for ATCOs can be pretty far ahead, depending upon what's going on in your sector. From my experience (not an ATCO though) controllers will generally try to anticipate the impact of their instructions on downstream sectors. Likewise, if their plan will go easier if a preceding sector does something different with their traffic, they will pick up the telephone and co-ordinate.

An ATCO always wants to be ahead of the traffic (proactive not reactive) so will plan as far forward as they are comfortable. This often means they are including traffic in other sectors in their scanning and planning, as well as actively working to keep them apart and moving most efficiently in their own sector.

[ferris]

Frequently we, here, plan your final level based on your estimate for a point 1hr 10 minutes from the end of our airspace. You may be cleared to that level, then get stopped on the way up due to a crossing conflict, which cannot be planned for as it's departure time will not be known until it actually departs, 10 minutes from the cross. If it departs plus or minus 4 minutes from planned, will determine whether it conflicts.

So to answer your question; we may be planning the big picture on a grand scale, but the small picture is a minute to minute affair.
Ever seen the guy juggle the bowling ball, the ping-pong ball and the apple, biting the apple along the way?

[eyeinthesky]

Another issue which is specific to Swanwick is that of electronic coordination.

With flights such as yours which climb in Swanwick's airspace, the initial sector(s) have to make a judgement of what is your requested (not always the same as filed) level (if you're not yet on frequency), what level you might make by the relevant sector boundary, what level might get accepted by the next sector considering their traffic, and any standing agreement issues. What generally happens is we will take a punt on that decision and offer electronically (to LMS in this case) a certain level. The time parameter for that offer to the next sector is set by the computer and we must get a level put in before the computer makes one up! The tactical controller (the one you talk to) will then see that level on his screen and climb you to it as his own traffic allows. It may well be (as in this case) that the next sector has conflicting traffic and will offer back a revised level for acceptance (280 in your case). This will be because of their assessment of where you fit in with THEIR traffic (it seems from your description that to accept you at 290 would have been a BAD idea!). You will then get the "At the request of the next sector..." speech. What we always hope is that the amended offer will come back BEFORE you have passed that level. Unfortunately that is not always so, so the roller coaster starts.

In summary, then, we all try to plan ahead as far as possible, but we are limited by the time constraints of the electronic data interchange and the tactical situation may be slightly different to the initial planned one.