250kts on departure
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250kts on departure
Just a quick straw poll, as the London TMA controllers are more than likely going to have to trial operations in March whereby we cannot take the 250kt speed restriction off you guys until you are above FL100.
This trial is supposedly going to stop aircraft 'bunching' at exit points (though how that will work when talking about 4 different major airports launching A/C independantly to the same exit points is a mystery to the coalface ATCOs)
The question I have is - our management, who are forcing this trial on us, inform us that the airlines have been informed....... to what extent do you guys know about this - or is it the case of both sets of management have agreed to the trial but not told the coalface workers??
What are your thoughts on this restriction?
This trial is supposedly going to stop aircraft 'bunching' at exit points (though how that will work when talking about 4 different major airports launching A/C independantly to the same exit points is a mystery to the coalface ATCOs)
The question I have is - our management, who are forcing this trial on us, inform us that the airlines have been informed....... to what extent do you guys know about this - or is it the case of both sets of management have agreed to the trial but not told the coalface workers??
What are your thoughts on this restriction?
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Re: 250kts on departure
never heard this recently (in the past year at least) to be honest unless you have a huge transit accross the TMA (eg towards dvr from the north and its busy) it does not make a huge difference time wise (max 1 mniute i reckon) so all in all if its the flow and possible reduction in being kept low or holding on arrival then it can only be a good thing.
Just to iterate - NO
Just to iterate - NO
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Re: 250kts on departure
May have some effect on the heavy jets wich prefer a high speed climb to clean up, but just means we, smaller twins, get to 100 sooner if we have to stick to a 250 limit.
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Re: 250kts on departure
(though how that will work when talking about 4 different major airports launching A/C independantly to the same exit points is a mystery to the coalface ATCOs)
Tactical VECTORING, not too dissimilar to approach radar methods, is the answer. At 250 kts you'll find aircraft a lot more "manoevrable" (they cover less ground in turns for instance).
AREA people have to do this in the UK and abroad (with varying degrees of success) daily. e.g. streaming into MAY, AVANT, DPE, MURUE.... corner posts etc , all from different points.
Haven't got "time" to do it? Split the sector. Give yourself more time. You may be surprised what is achievable.
Best Rgds
BEX
a coalface ATCO
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Re: 250kts on departure
It's standard SOP in the US, at least at every major airport I've ever operated into or out of. Never been given "no speed restriction" below 10,000' when arriving or departing from an airport over there.
With reference to the 'heavy' jets requiring greater than 250kts min clean speed, I've never had any ATC restrict us to the 250kts on departure. On the B744 at typical T/O weights before an Atlantic crossing, our min clean speed will be around 260-275 knots. We always climb at 250 or min clean, whichever is greater. Occasionally, ATC may want to know what our min clean speed will be for their own decision making reasons but invariably, they are well aware that a heavy a/c will be slightly above 250kt min clean.
As has been pointed out already, the typical time difference of reaching a boundary or entry/exit point between 250kts and 300kts is around one minute or less depending how quickly you can reach 10,000'.
Thoughts on the restriction? Won't really make much difference. What is preferable is more direct routings.
With reference to the 'heavy' jets requiring greater than 250kts min clean speed, I've never had any ATC restrict us to the 250kts on departure. On the B744 at typical T/O weights before an Atlantic crossing, our min clean speed will be around 260-275 knots. We always climb at 250 or min clean, whichever is greater. Occasionally, ATC may want to know what our min clean speed will be for their own decision making reasons but invariably, they are well aware that a heavy a/c will be slightly above 250kt min clean.
As has been pointed out already, the typical time difference of reaching a boundary or entry/exit point between 250kts and 300kts is around one minute or less depending how quickly you can reach 10,000'.
Thoughts on the restriction? Won't really make much difference. What is preferable is more direct routings.
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Re: 250kts on departure
Cough
Thats the worry we have, that you guys flying the aircraft have not yet been told. So unless you do, we are going to be hit with the 'can we accelerate yet' question all the time.
Bexil
We do not have the time nor the space ... you should know that because of the way that we are presented with traffic running into Heathrow and Gatwick from the south (as your name implies you know this area). We often get traffic running abreast and certainly not streamed. Lets not turn this into a Swanwick/TC bunfight. The bunching will happen regardless of initial speeds. If the anticipated result is aircraft in one nice stream - it's not gonna happen. A/C will climb quicker, but we rely on knowing that certain aircraft will be very fast a 6000' so that we know they will clear the holding areas and be free to climb sooner.
As for Tactical vectoring - I think you will find we kinda know how to do this at TC due to the multitude of crossing tracks; but both you and I digress - the original post was to find out what the guys and gals at the other end of the Mic thought and also to find out if they had been told anything yet because our managment assures us they have.
BusyB1
The acceleration of A/C to clean up has not even been addressed - beyond the managments limited brainpower to realise the implications of letting some guys accelerate to clean up and the new separation problems that will pose... only so much vectoring we can do if you are stuck under the stacks and there are departures from Heathrow and Gatwick climbing to the same SID level, going to the same point!
Taking away these sorts of tactical tools form the coalface worker is another management interference and proves how little todays managers understand the coalface workers problems.
Eager Beaver
It won't help flow, it just means that A/C will get to the fix a minute or two later... airports will still be firing them off at the same interval - restrict that and you will benefit flow.
It is only for outbounds, it will have no impact on holding arrival. If you are going to hold, you will hopefully have been instructed to slow down before then anyways - usually as soon as you have level separation from any other A/C running in alongside you and you have met the level by restrictions.
You can't really restrict speed much more before then as the en route area guys (like Bexil) need the speed to make sure you get the height off, and to start implementing spacing as they usually get you in a bunch from the French.
We also need to make sure you get the height off to have you in levels which are separated from all the other holding areas.
Slim Shady
If we can get you in the clear to climb we will, then as you say, you can accelerate. So the 'natural separation' we have with different A/C types is also being taken from us to a certain extent!
Danny
That is exactly the point - it won't make much difference so why complicate matters? We are going to have some aircraft accelerating to get clean others doing 250kts, then the A340!!
Direct routeings are more the realm of the en-route guys - they have to sort the rubbish we throw at them before they can start doing that for you!! Tho if its quiet we will try to send you direct, but in a lot of cases it does not comply with En-routes separation requirements regarding parallel routes.
What galls us is the fact that our tactical tools are slowly being eroded by management
Thats the worry we have, that you guys flying the aircraft have not yet been told. So unless you do, we are going to be hit with the 'can we accelerate yet' question all the time.
Bexil
We do not have the time nor the space ... you should know that because of the way that we are presented with traffic running into Heathrow and Gatwick from the south (as your name implies you know this area). We often get traffic running abreast and certainly not streamed. Lets not turn this into a Swanwick/TC bunfight. The bunching will happen regardless of initial speeds. If the anticipated result is aircraft in one nice stream - it's not gonna happen. A/C will climb quicker, but we rely on knowing that certain aircraft will be very fast a 6000' so that we know they will clear the holding areas and be free to climb sooner.
As for Tactical vectoring - I think you will find we kinda know how to do this at TC due to the multitude of crossing tracks; but both you and I digress - the original post was to find out what the guys and gals at the other end of the Mic thought and also to find out if they had been told anything yet because our managment assures us they have.
BusyB1
The acceleration of A/C to clean up has not even been addressed - beyond the managments limited brainpower to realise the implications of letting some guys accelerate to clean up and the new separation problems that will pose... only so much vectoring we can do if you are stuck under the stacks and there are departures from Heathrow and Gatwick climbing to the same SID level, going to the same point!
Taking away these sorts of tactical tools form the coalface worker is another management interference and proves how little todays managers understand the coalface workers problems.
Eager Beaver
It won't help flow, it just means that A/C will get to the fix a minute or two later... airports will still be firing them off at the same interval - restrict that and you will benefit flow.
It is only for outbounds, it will have no impact on holding arrival. If you are going to hold, you will hopefully have been instructed to slow down before then anyways - usually as soon as you have level separation from any other A/C running in alongside you and you have met the level by restrictions.
You can't really restrict speed much more before then as the en route area guys (like Bexil) need the speed to make sure you get the height off, and to start implementing spacing as they usually get you in a bunch from the French.
We also need to make sure you get the height off to have you in levels which are separated from all the other holding areas.
Slim Shady
If we can get you in the clear to climb we will, then as you say, you can accelerate. So the 'natural separation' we have with different A/C types is also being taken from us to a certain extent!
Danny
That is exactly the point - it won't make much difference so why complicate matters? We are going to have some aircraft accelerating to get clean others doing 250kts, then the A340!!
Direct routeings are more the realm of the en-route guys - they have to sort the rubbish we throw at them before they can start doing that for you!! Tho if its quiet we will try to send you direct, but in a lot of cases it does not comply with En-routes separation requirements regarding parallel routes.
What galls us is the fact that our tactical tools are slowly being eroded by management
Re: 250kts on departure
personally when departing heathrow and being held at 6000ft I am happy to be allowed to speed up to get away from the heathrow holds but I do not have the big picture and I am happy to comply with any reasonable request to help everyone on their way. Lets also bear in mind that most bird strikes occur below 10,000 ft and the cockpit windows are not tested for bird strikes at 280 kts.
Safe flying everyone
Safe flying everyone
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Re: 250kts on departure
In the US, ATC are not allowed to cancel the 250kt limit below 10,000ft. However, the restriction does not prevent you from flying at minimum clean speed. FAR 91.117(d) states; "If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed".
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Re: 250kts on departure
Whilst it is nice to be able to speed up it really does not actually make a lot of difference from my point of view, saves a fraction on time and fuel but not enough to matter. I would have thought that it makes more difference in flow control for ATC to be allowed to speed aircraft up so you can give the guy at the front of a queue of other aircraft a bit of a lead.
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Re: 250kts on departure
GWH
Yep - point taken however a lot of the time we keep EGKK Lam Deps at low speed - this helps them outclimb the Biggin stack and also means the radius of turn is smaller as it is less of a turn back to keep you clear of EGLL traffic inbound from the north east. (And turn radius is less)
That is us using speed as a tool - we are about to be denied using speed as a tool in different ways for different A/C.
Just to clear that up GWH as it may seem we are talking at cross purposes, I understand your true ROC may be less, but in ATC terms, although we may want a high fpm rate, what we are looking at in reality for us is your actual feet per mile rate. When you have accelerated, we are still judging your climb rate on how far away your traffic is.
We both want a good climb at times, but interpret it in different ways!
Yep - point taken however a lot of the time we keep EGKK Lam Deps at low speed - this helps them outclimb the Biggin stack and also means the radius of turn is smaller as it is less of a turn back to keep you clear of EGLL traffic inbound from the north east. (And turn radius is less)
That is us using speed as a tool - we are about to be denied using speed as a tool in different ways for different A/C.
Just to clear that up GWH as it may seem we are talking at cross purposes, I understand your true ROC may be less, but in ATC terms, although we may want a high fpm rate, what we are looking at in reality for us is your actual feet per mile rate. When you have accelerated, we are still judging your climb rate on how far away your traffic is.
We both want a good climb at times, but interpret it in different ways!
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After a season on the north american continent i no longer see any need to accelerate past 250 below ten , going up or down, unless specifically requested. Climbing at high speed , cruising at high speed and descending at high speed use more fuel,(particularly in V/S)than they make up in time saved.According to my observations that is.
It does increase your chance of missing someone in a Fecked up situation, either an errant intruder or an unsure vistor to cas. If its good for that reason in uncas then its good for cas. Cant see any advantage to speeding up.
It does increase your chance of missing someone in a Fecked up situation, either an errant intruder or an unsure vistor to cas. If its good for that reason in uncas then its good for cas. Cant see any advantage to speeding up.
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One thing that occurs to me is that pretty much every one can do the 280kts min clean speed of the heavy -400 but the -400s can't do the 250 standard speed without dragging flaps around and vastly increasing the fuel burn. My airline, a 737 operator wants us to get to econ climb speed as soon as possible after clean up for cumulative fuel (and emissions) savings. 280kts is a pretty good econ speed for the 737 and I should imagine most aircraft of that weight. Why not introduce a standard speed of 280 kts which every departing aircraft could adhere to and reduce fuel burn, flight times and emissions?
Kirk out…
Kirk out…
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As far as bunching goes, surely that is best avoided by everyone flying the same speed. What that speed should be will vary between aircraft types and operators requirements. Maybe the operators should be canvassed and then a compromise speed be arrived at. 280kts gets my vote, its a middle of the road speed with room to slow down or speed up comfortably by most types and closer to econ climb speeds than 250kts is. BTW this is the first i've heard of it as well.
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OK, I realise that the point being made here is:
and based on the original question:
then as far as I'm concerned it makes very little difference except that anything that gets us pointed in the right direction and above all the low level traffic and on our way can't be bad. However, I am concerned if it is likely to be a retrograde step for you as an ATCO and is only being implemented as some sort of empire building exercise for managements pleasure.
Just done a check of my company's crew notices and not seen any info about this 'trial'. So, not filtered down to the coalface yet, but then again, we don't go above 250kts/min clean unless cleared to do so. Don't usually bother asking for it as I don't have the 'big BIG picture' anyway and the service provided is always top notch. Now, don't get me started about going into Boston!
Originally Posted by ukatco_535
What galls us is the fact that our tactical tools are slowly being eroded by management
Originally Posted by ukatco_535
What are your thoughts on this restriction?
Just done a check of my company's crew notices and not seen any info about this 'trial'. So, not filtered down to the coalface yet, but then again, we don't go above 250kts/min clean unless cleared to do so. Don't usually bother asking for it as I don't have the 'big BIG picture' anyway and the service provided is always top notch. Now, don't get me started about going into Boston!
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on the 737 the min clean is around 210-220 kts.Selecting VNAV will set the commanded speed at 250 kts.The speed restriction of 250kts/FL100 is set in the FMC ,and it's our SOP to follow that if not otherwise requested by the ATC.This will give the highest ROC to FL 100 ,most of the time.
The climb speed will be 280 kts( if turbulence expected) or something around 300 kts .
In London TMA,having to stop at FL60, we'll have to mantain 250 kts for a longer period of time.From what I've got from you,ATCO people,a higher speed will help by getting us faster out of your TMA. Of course ,with this trials that you've talked about ,things must be diff.
And,no,no-one told us at our comp about those trials you're doing at London TMA.
The climb speed will be 280 kts( if turbulence expected) or something around 300 kts .
In London TMA,having to stop at FL60, we'll have to mantain 250 kts for a longer period of time.From what I've got from you,ATCO people,a higher speed will help by getting us faster out of your TMA. Of course ,with this trials that you've talked about ,things must be diff.
And,no,no-one told us at our comp about those trials you're doing at London TMA.
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It's undoubtedly true that those on the various flight decks have no knowledge of this "trial". It seems to take a LONG time for the info to get from NATS to the Airlines to the Ops dept to the Pilots.
Why so? Dunno, but would hazard a guess there is a bottleneck somewhere on the airlines side. The info certainly is sent out to them.
The idea here is soley about better traffic presentation for aircraft exiting the LTMA, which will allow a greater throughput to the en-route sectors. The aircraft may not be at their best speed or even altitude, but they will be moving in an orderly fashion in the right direction.
The alternative is more departure restrictions, be they MDIs or simply holding selected traffic on the ground. Not good for anyone.
Whether a 250kt for all restriction is a good idea remains an untested one.
Bunching remains one of the biggest causal factors of Overloads. In the not too distant future the en-route sectors WILL refuse to accept traffic from the LTMA if poor presentation is leading to bunching and an unsafe situation. Just the same as TC quite rightly stop inbound traffic if neccessary.
Start to look at holding deps at SAM, DVR, CPT etc and stopping any futher departures until AREA can accept the traffic
With regard to LTMA inbounds, yes sometimes presentation is less than ideal and I regret that, and apologise. The reason is the short distance and high flight levels of traffic from Northern France. It's not always possible to restrict A/c speeds drastically in descent because they will not achieve the target levels. If presenation isn't brilliant, you can still "go vertical" and descend in the hold. Not pretty or pefect, but completely acceptable to approach.
There is no suggestion of "bashing" the opposition, be they AC or TC. The idea is to get the greatest (and safest) traffic through put. Examining long held cultures and ideas isn't always popular, but can lead to positive changes. There may be a better way.
Best rgds BEX
Why so? Dunno, but would hazard a guess there is a bottleneck somewhere on the airlines side. The info certainly is sent out to them.
The idea here is soley about better traffic presentation for aircraft exiting the LTMA, which will allow a greater throughput to the en-route sectors. The aircraft may not be at their best speed or even altitude, but they will be moving in an orderly fashion in the right direction.
The alternative is more departure restrictions, be they MDIs or simply holding selected traffic on the ground. Not good for anyone.
Whether a 250kt for all restriction is a good idea remains an untested one.
Bunching remains one of the biggest causal factors of Overloads. In the not too distant future the en-route sectors WILL refuse to accept traffic from the LTMA if poor presentation is leading to bunching and an unsafe situation. Just the same as TC quite rightly stop inbound traffic if neccessary.
Start to look at holding deps at SAM, DVR, CPT etc and stopping any futher departures until AREA can accept the traffic
With regard to LTMA inbounds, yes sometimes presentation is less than ideal and I regret that, and apologise. The reason is the short distance and high flight levels of traffic from Northern France. It's not always possible to restrict A/c speeds drastically in descent because they will not achieve the target levels. If presenation isn't brilliant, you can still "go vertical" and descend in the hold. Not pretty or pefect, but completely acceptable to approach.
There is no suggestion of "bashing" the opposition, be they AC or TC. The idea is to get the greatest (and safest) traffic through put. Examining long held cultures and ideas isn't always popular, but can lead to positive changes. There may be a better way.
Best rgds BEX