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270KT outer speed limit for london TMA

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270KT outer speed limit for london TMA

Old 19th May 2008, 16:15
  #21 (permalink)  
 
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The problem with trying to get LL inbounds in trail is all to do with the size of the UK. For example coming from the east (northern europe, eastern europe, far east, middle east and scandinavia) you have about 60 miles in which to stream the traffic and you very regularly get 6-8 at a time and another 4 very close behind, you can't get 10 miles in trail let alone 20. To do that MAAS would have to start streaming for us over northern europe and to be frank they are far to busy with their own problems to do that.
1985, I salute you from MAAS (via COA & DENUT) and lift my hat gracefully for your understanding of our situation. As you rightfully say we do have our own problems (the Belgian UIR with up to 2300 flights per 24h is as full as an egg) but whenever we can we will try (on demand or on own initiative) to provide longitudinal (preferred) or lateral separation. Despite ourselves being busy I never cease to be amazed at the amount of traffic we are throwing at you guys down the line and how you are handling it.
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Old 19th May 2008, 18:17
  #22 (permalink)  
 
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1985, I salute you
well its about time someone did

In all seriousness though, hopefully someone will realise when they get the CLN comments book back (there are no positive ones) that it just isn't feasible for the short sectors to do it. The west end might manage it occasionally, but if one side does it and the others don't whats the point?

I also don't think the stack swap issue is that complex, surely its about relieving pressure on LAM, so any aircraft will do? I realise there is a plan but it needs to be flexible, if there are two running together and the BIG is to the north why not take the arrival to the south instead? It makes life easier for me and the TC bods. The whole point of plans in ATC is that they change from minute to minute so why continue with one that was made 20 mins ago by a GS who can't even see the radar? CLN needs to be told really early so they can set it up or not at all, and it needs to be sensible choice, the northerly of four because its a speedbird and therefore should speak better english (debatable) is not sensible.
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Old 19th May 2008, 20:17
  #23 (permalink)  
 
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1985, another consideration when choosing the stack swap is whether it's a good TEAM arrival. If it's going to land on the southerly runway, it's better routed to a southerly stack. Then FIN's job is easier so the landing rate remains robust and the delays go down.
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Old 19th May 2008, 21:36
  #24 (permalink)  
 
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1985. I think you need to come into the TC room. The GS is looking at a long range radar, filtered for LL. They also may be using Mode 'S' info. They always try and make the best judgement for the system. If they do something you do not like, come and have a discussion. You may not be looking at 'the big picture', they are.
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Old 19th May 2008, 21:56
  #25 (permalink)  
 
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I have, i've seen the long range radar but that still doesn't make the choices that are made the correct ones at the time, they may have been the correct aircraft to choose 200 miles away but that doesn't make them correct when we get told to stack swap. It needs to be sorted over europe so that we can do it early or done in TC's airspace.

As for the big picture, recently we were holding at LOGAN, and TC rang up and said the next one that was going into the hold was a stack swap and was needed at 220 so TC could get it under BRASO. This was at FL300 10 miles from LOGAN with two in LOGAN, how possibly are we going to do that? Stupid call from someone very clearly not looking at the "bigger" picture.
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Old 20th May 2008, 16:47
  #26 (permalink)  
 
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Just out of interest, what did LTC say when you pointed out the difficulties?
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Old 21st May 2008, 09:26
  #27 (permalink)  
 
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zkdli

The TC east controller was fine after i said no, the point i was making is that the GS or traffic manager shouldn't be making these decisions so late or without looking at the radar, which is the impression that it gives off.

I've since spoken to TC and hopefully some of us are on the same songsheet now at least on our watch
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Old 21st May 2008, 19:59
  #28 (permalink)  
 
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1985
Thanks for your reply I was hoping that you would say something along those lines it is doing just as you have done that will get the system working better.
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Old 22nd May 2008, 07:59
  #29 (permalink)  
 
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The 270 kts idea is only a suggestion. It came from some of the major airlines working with NATS to try to reduce fuel burn in the hold and the ridiculous practice of doing 300kts + to get the lowest level in the hold and then fly around in circles for 20 mins. Of course the CTC people were involved in evaluating the ideas, but I don't think anyone won an IPOD for it.

It's all part of being aware of the big picture:

If there is no holding, then don't apply it.
If the aircraft's ECON speed is 290kts and you don't need to increase that for separation then don't.
Why do so many people impose a speed differential of 10 kts (300/290/280) on aircraft which are ALREADY 5 miles or more in trail? If they didn't do that they wouldn't feel the need to make the first one do 300 or more just to stop the back one from falling out of the sky.
How many Ts or Ps regularly assess the delays at LAM by looking at the radar at the stack compared with the 'Less than 20 mins' response derived from the SIS page? Very few planners I've observed keep their tacticals appraised of the delays (10 mins or whatever) on a regular basis unless they are into or just coming out of EATs.
Why would anyone with half an idea of ATC feed traffic at 300 kts into a hold 'for separation reasons'? Sort them out earlier and use headings and early descents to get them at a reasonable speed. Accelerating towards a red traffic light seems a daft idea!
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Old 22nd May 2008, 09:11
  #30 (permalink)  
 
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If there is no holding, then don't apply it
I don't and won't
If the aircraft's ECON speed is 290kts and you don't need to increase that for separation then don't
I don't but how do i know what an aircrafts econ speed is if they don't tell me? It varies from type to type, series to series within a type and from airline to airline. And to be frank i don't have enough RT time to ask.
Why do so many people impose a speed differential of 10 kts (300/290/280) on aircraft which are ALREADY 5 miles or more in trail? If they didn't do that they wouldn't feel the need to make the first one do 300 or more just to stop the back one from falling out of the sky.
Its would be because of the relationship between IAS and ground speed at different levels, i thinks its something like 7 kts IAS per 1000 feet equates to the same ground speed. If i'm streaming two or three with about 3000 feet between each then i'll use a less IAS to keep them separated. AFAIK TC do not appreciated 7 miles in trail with a 30 kt catch up.
How many Ts or Ps regularly assess the delays at LAM by looking at the radar at the stack compared with the 'Less than 20 mins' response derived from the SIS page? Very few planners I've observed keep their tacticals appraised of the delays (10 mins or whatever) on a regular basis unless they are into or just coming out of EATs.
All of us i hope. SIS is sh*t and everyone knows that, the problem with looking at LAM and trying to judge the delay, is that you can look at it not see many there and then be told its BRASO holding. Happens more than you think.
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Old 22nd May 2008, 10:58
  #31 (permalink)  
 
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spot on 1985
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Old 22nd May 2008, 13:46
  #32 (permalink)  
 
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typical atco's

maybe another 50 in your pockets, (per hour probably!!) or a few less hours work and you'd agree to the 270kts
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Old 22nd May 2008, 15:12
  #33 (permalink)  
 
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Big Paddy

I assume that's a wind up if not, you really haven't got a clue have you?

The reason we think it's a crap idea is it removes flexibility.

Speed control is a major tool used for inbound aircraft. Only a non ATCO would fail to understand that.

Maybe you are a failed ATCO? What was the probelm - inability to be flexible or lack of ability to be able to think for yourself and come up with solutions in an ever changing and fluid environment??

Can you suggest how to merge 3 or 4 streams of aircraft into one orderly line without the use of speed in UK airspace?
These are aircraft that when the streaming commences are in excess of 100 miles from the hold... how the hell is 270Kts or any speed set down by some numpty in an office going to work and how can it be more green if aircraft have to fly for longer?

The speed is just a suggestion, but here's a better suggestion - ignore it.

Blindly following it will reduce controller's capacity and thus drive up delays.
It will also cause unnecessary holding because A/C that could have been high speed to get a no delay approach will often end up arriving at the same time as aircraft approaching the hold facility from other sectors.

270Kts is a stab in the dark speed thought up by someone who has not got a clue about the fact that different types of aircraft have different econ characteristics.
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Old 22nd May 2008, 17:01
  #34 (permalink)  
 
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Some interesting stuff here. How a blanket 270kts can be imposed is beyond me.

As has been mentioned, if everything comes over over to the TMA sector at 270kts (or 300 or 250) no matter what the grouping, then that is not speed control - it's a mess which may require dog-legs, speeding up and slowing down of certain aircraft. R/T loading is increased and fuel is actually wasted not saved.

If the En-route sector has to get everything at 270kts and in trail then that could be a lot of work (especially if their hands are tied with the speed). If there is no holding it's wasted R/T time (and in the LTMA especially it could actually lead to wasted runway utilisiation). If there is holding it may not help TMA out enough.

The only thing I can think of for introducing it is tenuous:
If an aircraft meets the Standing Agreed level between En-route and Terminal, as well as being at 270kts; the TMA Tac can ask for the aircraft to increase speed and get a slightly better rate of descent or reduce speed on an aircraft, and with less speed to lose, their rate of descent won't be as bad for as long as it would be reducing from 310kts+.

I'm at MACC and would hate to see this 270kts come in for us. The presentation between TMA and En-route is getting better all the time and we are speaking to each other more about sequencing.

I think the key to all this is awareness of what the receiving guy is trying to do as well as understanding the possible difficulties the offering guy may face in trying to help.

Being aware of other sectors around you whilst you are busy yourself is an art - possibly even a luxury you can't afford when things are really hot.

As a Tactical at MACC, when you're busy, it means you need a good Planner at your side.

And/or good coordination between TTM/GS/LAS/Bank Sups? (4 centres 4 names!) can help. This has to be done with reference to the radar/TSD, workloads and the other stacks being fed at the relevent airfield.

Until we get arrival manager tools which tell us on the radar what speed to assign from medium to long range, we'll all have to earn our corn Controlling and that includes choosing the speed which suits us, adjacent sectors and as many aircraft as possible. That speed is not a blanket 270kts. Good luck and pardon my input on matters LTMA!
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Old 23rd May 2008, 09:11
  #35 (permalink)  
 
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eyeinthesky

I was happy with some of your input until you shot yourself down in flames with a couple of howlers.
300/290/280 for three in trail.....anyone using the same speed for all three is probably an office-hero doing his/her 6 hours a month "I'm-lowering-myself-to-work-with-you-peasants-to-show-you-how-its-done" moron. An experienced operational controller will be mindful of wake vortex and the 2% per thousand feet IAS/TAS differential, and the fact that 5 miles can become 4 miles very easily.
As for appreciation of delays......if you can arrange for the supervisor to actually tell the poor bloody infantry scope-jockey what the delays are...then we can slow everything down.
P.S. Of the 20 or so pilots that I asked the other day.......not one single pilot requested an econ descent of 270......they were all in the 300-280 range with one exeption who asked for 250 because he was early and the stand wasn't available yet.
P.P.S. I don't like the trend for supervisors and even more remote non-operational personnel trying to influence tried and tested controlling technique at too late a stage in the proceedings when flow control and pro-active traffic planning have utterly failed. If you want to control my sector then get a validation, put a headset on, plug in and get on with it.
P.P.P.S. Anyone read the LACC Swanwick MATS 2 ? We are supposed to get the traffic into the TMA.....not keep it out! Please advise if there has been a major policy change.
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Old 23rd May 2008, 14:04
  #36 (permalink)  
wizad
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eye in the sky, you must be some sort of ctc office monkey, probably one who dreamed up this jackass procedure... yet again this morning aircraft high due doing 270kts... a quick phonecall and procedure cancelled for the day... again.

tell you what, come into one of our ops rooms when its going hell for leather and come see what happens when planes dont make level restrictions for standing agreements:
1) conflict with traffic from other directions that it should be under and is now aiming at and going straight through it. if i have to fill out a star, my first line will be ' due to the 270 knot speed trial.....'
2) aircraft high may not be able to get the height off when there is no delay and end up in the hold to loose it..... cos thats going to help us all.
3)getting 5 abreast instead of streamed as youve taken AC's flexibility away... guess what matey. if they are not streamed into the stacks.... they enter the hold when they normally wouldnt have to.
4) if there is no delay, why not let the pilot fly at his desired speed (usually faster) for another 60 miles plus, if he wants to slow down to save an iceberg near santas house they will tell us.

you can drag me into as many meetings as you like and tell me to do it, i still wont.

funny thing is, we get all emails and lovely signs and bits of paper telling us what a great idea this is and how its going to work.... why dont you get out from under your desks and come plug in with us and have a proper discussion about it.... you would get a lot less resistance and probably learn more than reading about procedures in your bedtime story book.

with one hand the company wants more planes rammed through our sectors, then with the other starts to take away our tools to get this done.
oh and while im here.... the best idea that probably took 15 of you tie wearing tools to decide was to bring this in during summer traffic... well done... complete lack of understanding.

feedback welcome.

W
 
Old 25th May 2008, 20:58
  #37 (permalink)  
 
Join Date: Feb 2001
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Thanks for the feedback, at least from those of you who didn't feel the need to be abusive about it...

Just because someone offers an opinion with which you disagree doesn't give you permission to resort to personal abuse: "you tie wearing tools", "you must be some sort of ctc office monkey" etc. At least try and have a reasoned debate. Otherwise YOU are the monkey. If you must resort to abuse, at least try and write in properly punctuated sentences.

Back to the point:

It's a trial: Try it properly, give people the chace to get used to it and its timely imposition and then give proper feedback and suggestions for improvements. If you keep cancelling it then it will never be properly evaluated, adapted, changed or abandoned.

Speed control is about matching groundspeeds not airspeeds. If a 10kt IAS differential is actually achieving an increasing distance between aircraft which already have enough separation then it is an incorrect application of speed control.

Couldn't agree more about the need for communication across the board. But we all have to do our bit, and some of the attitudes displayed on this thread don't encourage me to think that it's happening every day!

By the way, the experts tell us that variable speed limits on the M25 reduce bunching. They only come in when traffic is heavy enough to merit it. 270kts could be seen to be like them.
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Old 25th May 2008, 21:25
  #38 (permalink)  
 
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I just want to know one thing eyeinthesky....did you win the iPod this month?
Oh no, hold on....the ipod went to the person who suggested that, as a safety measure, we should routinely cross out vacated levels on our flight progress strips. Wish I'd thought of that........

Last edited by mr.777; 25th May 2008 at 21:53.
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Old 25th May 2008, 21:52
  #39 (permalink)  
 
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P.S. Of the 20 or so pilots that I asked the other day.......not one single pilot requested an econ descent of 270......they were all in the 300-280 range with one exeption who asked for 250 because he was early and the stand wasn't available yet
For a BA A319/320/321 "Econ Descent" is invariably in the ~270KIAS area. However, this is "best range speed" (adjusted for Cost Index i.e. an element of slightly increased Fuel Comsumption against Time in the air) and is instantly invalidated if there is to be any holding.

If the aircraft is to hold (and I appreciate it is hard for you to determine), then "Econ speed" is Holding speed throughout the descent. This is "Endurance speed" and we are told the landing order is determined "40 minutes out". The sooner we can be told "there is ~x minutes @ LAM, reduce to Holding Speed if you wish, or when FL150 @ SABER met.." the better

As alluded to above, this is why (some) get a little grumpy when told to accelerate to 280K / 290K / 300K and then to hold. It is very costly in terms of fuel, both , but as crucially, in "holding time" then remaining available (very roughly, every 2 minutes @ 280K equates to 3 minutes holding i.e. loses a minute of total holding capability/endurance).

I fully appreciate you will get 20 different stories from 20 different pilots... and this is why a consistent line is needed from the airlines

NoD
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Old 26th May 2008, 08:42
  #40 (permalink)  
 
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QUOTE

I just want to know one thing eyeinthesky....did you win the iPod this month?
Oh no, hold on....the ipod went to the person who suggested that, as a safety measure, we should routinely cross out vacated levels on our flight progress strips. Wish I'd thought of that........

UNQUOTE

And of course you, being perfect Mr777, do that every time anyway because the strip marking requirements in the MATS say you should? Yeah, right!
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