Heathrow Holding.
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Heathrow Holding.
I have really noticed a reduction in the times we are now holding going into Heathrow since the introduction of speed control from the inbound sectors to the Heathrow arrivals. Does anyone know any official statistics on this?
Thanks from all the pilots
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Thanks from all the pilots
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It could have been to do with AMAN (Arrival Manager) at Swanwick Terminal Control which ideally should sequence all inbound aircraft without the need of putting them to the hold. As I said, this is an ideal world and work is still ongoing.
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We're not doing anything different. As beaver liquor says, it's probably down to a drop in traffic.
We have had a new system introduced called AMAN which is supposed to provide accurate and up to date delay information. It's still not perfect but for those short periods where the information displayed is accurate, it can help us plan ahead better which in turn may enable us to slow you down at the correct time to prevent holding.
We have had a new system introduced called AMAN which is supposed to provide accurate and up to date delay information. It's still not perfect but for those short periods where the information displayed is accurate, it can help us plan ahead better which in turn may enable us to slow you down at the correct time to prevent holding.
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<<which ideally should sequence all inbound aircraft without the need of putting them to the hold. As I said, this is an ideal world and work is still ongoing.>>
Fascinating stuff, but how on earth will that be achieved given that up 20 can be holding at any one time, especially early in the morning? Is it going to vector them all over southern England?
Fascinating stuff, but how on earth will that be achieved given that up 20 can be holding at any one time, especially early in the morning? Is it going to vector them all over southern England?
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It's all to do with slowing them up earlier so that they absorb the delay enroute to the stack not just while they are in it. There will still be delays when there are lots of aircraft inbound, it just theoretically, the actual going round and round in circles should be less because they have been slowed up earlier.
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It's all to do with slowing them up earlier so that they absorb the delay enroute to the stack not just while they are in it. There will still be delays when there are lots of aircraft inbound, it just theoretically, the actual going round and round in circles should be less because they have been slowed up earlier
Except that when we all see the same delays we all slow the inbounds to the same speed and they still end up at the hold at the same time as everyone else......
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which ideally should sequence all inbound aircraft without the need of putting them to the hold. As I said, this is an ideal world and work is still ongoing.
AMAN is supposed to give controllers more accurate information to improve planning. When it does this (for about 30 minutes total in each shift) it does help. The trouble with the system is distinguishing between accurate figures and rubbish figures - a process which often increases workload beyond that of the old system.
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OK. I thought that was what pilots disliked about the US system - slowed down many miles from touchdown. Be interesting to get some aircrew input..
Things have moved on HD.
I actually think the original poster is correct in that the reduced speeds at an earlier stage is now helping to reduce inner stack delays. Heathrow has only seen a small drop in movements so I'm not sure it is down to this.
Last edited by 250 kts; 18th Feb 2009 at 08:07.
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We have been reducing speeds in TC for years.. dont need any fancy multi-million AMAN to tell us that.
Funny, now this is in some folk would think we let planes hurtle in at 300+ knots then pull back the speed 5 miles before the hold.
It's the same as its always been.... if there is a hold then you slow them down asap therefore my common sense tells me there will be less holding or maybe a quick call to approach to check.... We dont need a 'magic' machine, its called experience and common sense.
On the other side, AMAN is still very far from being accurate. I havent really used it as such and it will regularly show aircraft with 10 mins plus delay who are on the ILS.
Most days on our watch, LL actually take more aircraft from the holds than AMAN says they should and gets them landed quicker... what a great tool.... it adds delays. Another 'fine' thing this programme does is mix up the vortex categories for the landing order. So instead of landing a load of mediums with minimal spacing, it will stick heavies, lights and the odd A380 in there.... maximum runway utilisation out the window then.
If I were to keep to what AMAN tells me, you would be flying slowly into LAM when in reality you could be gear down and number 4 to land. Which would you rather???
Maybe when its all sorted we may see some benefit.... yet to be convinced
Oh and well done project team..... successful implementation my arse. You've spent millions on what we were doing anyway!!!
At least my job is safe for the future as it shows that computers are not as good as the old grey matter. Should have spent those millions on a decent payrise for your employees mister barron.
Funny, now this is in some folk would think we let planes hurtle in at 300+ knots then pull back the speed 5 miles before the hold.
It's the same as its always been.... if there is a hold then you slow them down asap therefore my common sense tells me there will be less holding or maybe a quick call to approach to check.... We dont need a 'magic' machine, its called experience and common sense.
On the other side, AMAN is still very far from being accurate. I havent really used it as such and it will regularly show aircraft with 10 mins plus delay who are on the ILS.
Most days on our watch, LL actually take more aircraft from the holds than AMAN says they should and gets them landed quicker... what a great tool.... it adds delays. Another 'fine' thing this programme does is mix up the vortex categories for the landing order. So instead of landing a load of mediums with minimal spacing, it will stick heavies, lights and the odd A380 in there.... maximum runway utilisation out the window then.
If I were to keep to what AMAN tells me, you would be flying slowly into LAM when in reality you could be gear down and number 4 to land. Which would you rather???
Maybe when its all sorted we may see some benefit.... yet to be convinced
Oh and well done project team..... successful implementation my arse. You've spent millions on what we were doing anyway!!!
At least my job is safe for the future as it shows that computers are not as good as the old grey matter. Should have spent those millions on a decent payrise for your employees mister barron.
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Traffic at Heathrow is down by at least 10%, this has much to do with it. There is still extensive holding taking place at certain times of the day due to bunching.
We are still on winter schedules, with a drop in normal numbers of at least 10%. Ut is the quietest time of the year anyways, without the economic downturn.
AMAN is all very well, but when you have 3 different AC sectors feeding traffic to the TMA for one hold (say OCK), unless they talk to each other, aircraft will still arrive at the same time, regardless of what speed reduction they are given.
For AMAN to truly work, we would need en-route to look at AMAN, work out the delay or time to make up then say to each aircraft "arrange your flight to arrive at XXXHold at XXXXtime".
En-route do not have the capacity to do this, their airspace dimensions are simply not large enough and they also have standing agreements to meet, which sometimes requires high speeds. Coupled with that they need to use different speeds to present traffic properly.
We certainly don't have the airspace to do it in TC.
AMAN would be good in uncomplicated wide open airspace. As it is, it provides (when it works correctly), the arrival sequence information (it doesn't 'do' the sequencing UlsterPPL). Ideally this would start before the aircraft coast in when coming over the ocean, but that's not part of the AMAN brief.
Only yesterday, at a point when it was very quiet, AMAN was telling me that aircraft had no delay if they left the hold at xxxx time, but inreality they were coming straight off 10 minutes beforehand.
If I had slavishly followed AMAN, the aircraft would have been slowed down for no reason, and would probably had to have held, because it would have arrived at the same time as other aircraft!!!
AMAN is a tool, it does not replace good ATC practice.
If en-route follow AMAN rigourously, you will find the system failing even more until it becomes 100% accurate - this is because AC do not know if aircraft are likely to come straight off or have to hold. Slowing down aircraft just because AMAN says you need to is foolhardy. It should be used as an indication only.
We are still on winter schedules, with a drop in normal numbers of at least 10%. Ut is the quietest time of the year anyways, without the economic downturn.
AMAN is all very well, but when you have 3 different AC sectors feeding traffic to the TMA for one hold (say OCK), unless they talk to each other, aircraft will still arrive at the same time, regardless of what speed reduction they are given.
For AMAN to truly work, we would need en-route to look at AMAN, work out the delay or time to make up then say to each aircraft "arrange your flight to arrive at XXXHold at XXXXtime".
En-route do not have the capacity to do this, their airspace dimensions are simply not large enough and they also have standing agreements to meet, which sometimes requires high speeds. Coupled with that they need to use different speeds to present traffic properly.
We certainly don't have the airspace to do it in TC.
AMAN would be good in uncomplicated wide open airspace. As it is, it provides (when it works correctly), the arrival sequence information (it doesn't 'do' the sequencing UlsterPPL). Ideally this would start before the aircraft coast in when coming over the ocean, but that's not part of the AMAN brief.
Only yesterday, at a point when it was very quiet, AMAN was telling me that aircraft had no delay if they left the hold at xxxx time, but inreality they were coming straight off 10 minutes beforehand.
If I had slavishly followed AMAN, the aircraft would have been slowed down for no reason, and would probably had to have held, because it would have arrived at the same time as other aircraft!!!
AMAN is a tool, it does not replace good ATC practice.
If en-route follow AMAN rigourously, you will find the system failing even more until it becomes 100% accurate - this is because AC do not know if aircraft are likely to come straight off or have to hold. Slowing down aircraft just because AMAN says you need to is foolhardy. It should be used as an indication only.
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A double digit drop in air traffic movements in and out of LHR?
What was the drop last winter so we can tell how far from the norm this is?
The weather alone must have removed a few movements....
What was the drop last winter so we can tell how far from the norm this is?
The weather alone must have removed a few movements....
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To Hold Or Not
Just to add a few thoughts to all before. Thanks to the original poster for the words of appreciation. I think there are several factors at play but it is worth remembering that delay although sometimes inevitable, is absolute anathema to controllers. If we can save you any mile, any minute within safe practice, we will.
Bunching is not necessarily a bad thing. What we try to do when restrictions are needed or especially if they are known to be needed only temporarily, is to set flow restrictions very generously to allow as many aircraft as possible to enter the airspace. The thinking behind this especially when landing rates might vary at short notice is that, if you are holding only 25nm away, rather than on the ground at TXL or somewhere, we can seize every and any opportunity to get you on the ground in the London TMA. So, as in all matters, there is balance to be found. Notwithstanding comments about fuel consumption I hope it can be viewed as sometimes better to approach LTMA with 10-15 mins prospective holding subsequently cut short as controller managed sequencing optimises your opportunities to get the paying customer back on the ground.
AMAN is a work in progress and I have no doubt that it will continue to improve. Experience so far shows that in spite of the deep understanding by the Project of ATC practice, it is enormously difficult to capture every nuance of that practice in algorithms and machine logic. I believe we must be very restrained in raising customer expectation towards the eventual elimination of holding through en-route profile management. I am no Luddite but I view this Utopia as somewhat distant.
In the meantime let us never undervalue the human, pilot or controller, or the value that new tools, properly conceived, can bring to to the ATC system.
Bunching is not necessarily a bad thing. What we try to do when restrictions are needed or especially if they are known to be needed only temporarily, is to set flow restrictions very generously to allow as many aircraft as possible to enter the airspace. The thinking behind this especially when landing rates might vary at short notice is that, if you are holding only 25nm away, rather than on the ground at TXL or somewhere, we can seize every and any opportunity to get you on the ground in the London TMA. So, as in all matters, there is balance to be found. Notwithstanding comments about fuel consumption I hope it can be viewed as sometimes better to approach LTMA with 10-15 mins prospective holding subsequently cut short as controller managed sequencing optimises your opportunities to get the paying customer back on the ground.
AMAN is a work in progress and I have no doubt that it will continue to improve. Experience so far shows that in spite of the deep understanding by the Project of ATC practice, it is enormously difficult to capture every nuance of that practice in algorithms and machine logic. I believe we must be very restrained in raising customer expectation towards the eventual elimination of holding through en-route profile management. I am no Luddite but I view this Utopia as somewhat distant.
In the meantime let us never undervalue the human, pilot or controller, or the value that new tools, properly conceived, can bring to to the ATC system.
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Descent in the hold
Just a quick question to which I can't find an answer:
When we're cleared to descend in the hold at say BIG, LAM, OCK, do you like us to descend at 1000'/min? If we do, then you know exactly when we'll be level at the new cleared FL or altitude, ie one minute +/-, and you can breathe easier when you clear other traffic to descend above us. Some operators I know descend at 500'/min 'for passenger comfort'.
Or are you going to refer me to the AIP??
When we're cleared to descend in the hold at say BIG, LAM, OCK, do you like us to descend at 1000'/min? If we do, then you know exactly when we'll be level at the new cleared FL or altitude, ie one minute +/-, and you can breathe easier when you clear other traffic to descend above us. Some operators I know descend at 500'/min 'for passenger comfort'.
Or are you going to refer me to the AIP??
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Descending to the Hold
I am not very good on what might be AIP or similar guidance but I would tactfully ask you to consider this scenario from a slightly different point of view. I understand, of course, that there is a great deal going on on the flight deck at this stage of flight but, sometimes, with some flights, situational awareness seems to diminish a little.
I don't want this to appear harsh so I hope it will be accepted in the context of the undoubtedly excellent relationship between pilots and UK controllers
If there is holding at all (although situations vary) it is likely that there will be other aircraft behind you also to hold especially at LAM for LL. Rates of less than 500fpm then are a little anti-social and I think closer to 1000fpm is probably what most assists stack management in busy traffic.
I'd like to add a little extra background as from it you might see a way to help yourself. In high pressure approach levels at a given stack are FL70-120 although traffic will frequently enter higher. Traffic can leave the stack only at FL120 or below without additional co-ordination (quite apart from the fact that on LL (W) that's roughly a CDA level). So the more chaps we can get down to those levels the faster things move. One slow descent in or approaching the hold can cause a surprising backlog and leads to the retention of the aircraft on the en-route frequency. This again might to be your disadvantage; although aircraft are handled with great fairness on an essentially "first come - first served basis", it is inevitable that not every flight will be perfectly positioned (laterally) in the hold. On such occasions an inventive controller will bring chaps off in other than level order which can free up several levels - but this can only happen if all concerned are at suitable levels in the first place.
It became a bit of rambling answer but I hope it adds something.
I don't want this to appear harsh so I hope it will be accepted in the context of the undoubtedly excellent relationship between pilots and UK controllers
If there is holding at all (although situations vary) it is likely that there will be other aircraft behind you also to hold especially at LAM for LL. Rates of less than 500fpm then are a little anti-social and I think closer to 1000fpm is probably what most assists stack management in busy traffic.
I'd like to add a little extra background as from it you might see a way to help yourself. In high pressure approach levels at a given stack are FL70-120 although traffic will frequently enter higher. Traffic can leave the stack only at FL120 or below without additional co-ordination (quite apart from the fact that on LL (W) that's roughly a CDA level). So the more chaps we can get down to those levels the faster things move. One slow descent in or approaching the hold can cause a surprising backlog and leads to the retention of the aircraft on the en-route frequency. This again might to be your disadvantage; although aircraft are handled with great fairness on an essentially "first come - first served basis", it is inevitable that not every flight will be perfectly positioned (laterally) in the hold. On such occasions an inventive controller will bring chaps off in other than level order which can free up several levels - but this can only happen if all concerned are at suitable levels in the first place.
It became a bit of rambling answer but I hope it adds something.
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cojones,
The minimum rate of descent in the hold (unless the pilot says otherwise) should be 500ft/min. That's in the AIP at ENR 1.1.3.1 Para 2.3.
As long as you do at least that, and don't stop part way down, then do whatever you are comfortable with.
The problems tend to occur when aircraft descend at vastly different rates of descent or, having started going down and passed the magic 400ft from the level they've just left (that's when ATC can clear the next one down to the level just vacated), stop descending for some reason.
The minimum rate of descent in the hold (unless the pilot says otherwise) should be 500ft/min. That's in the AIP at ENR 1.1.3.1 Para 2.3.
As long as you do at least that, and don't stop part way down, then do whatever you are comfortable with.
The problems tend to occur when aircraft descend at vastly different rates of descent or, having started going down and passed the magic 400ft from the level they've just left (that's when ATC can clear the next one down to the level just vacated), stop descending for some reason.
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notlgw53,
I'm sure one of the main reasons LHR gets bunching, or perhaps a TMA sector gets overloaded, is because a bunch of 'helpful' controllers further back in the chain are providing route shortcuts (or slot busting on departure).
It may be an anathema not to save a mile/minute or two, but one controller's perceived favour may well be the proverbial straw for some other poor controller, who was relying on accurate flow control, later in the route.
Just to add a few thoughts to all before. Thanks to the original poster for the words of appreciation. I think there are several factors at play but it is worth remembering that delay although sometimes inevitable, is absolute anathema to controllers. If we can save you any mile, any minute within safe practice, we will.
It may be an anathema not to save a mile/minute or two, but one controller's perceived favour may well be the proverbial straw for some other poor controller, who was relying on accurate flow control, later in the route.
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I was wrong!
According to the January figures, Heathrow traffic dropped 2%, not 10%!!!
With all th eother tyraffic dropping, it does feel more, and I believe that February figures will show a higher drop.
The fact is, AMAN is not responsible for reducing holding by a significant amount, unfortunately
With all th eother tyraffic dropping, it does feel more, and I believe that February figures will show a higher drop.
The fact is, AMAN is not responsible for reducing holding by a significant amount, unfortunately