Approach sequencing at LGW
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mowgli,
you are right, dog legs make it easier to judge the turns in sequence.
BOAC,
Thanks for raising the topic.
you have a very valid point about fuel. I'll certainly consider giving a range from touchdown on leaving the stack if it is for extended vectoring (though usually 40ish miles, never eighty).
apart from the fuel issue, do you have a problem with a 50 mile circuit for 26L, first 25 at FL 70, 220kts, then a standard circuit for the next 25 ? or would you still prefer one more pattern at timba at FL70 ?
How do other pilots feel ?
As a general rule i never reduce an aircraft below min clean until about 12-18 miles unless something's gone wrong.
you are right, dog legs make it easier to judge the turns in sequence.
BOAC,
Thanks for raising the topic.
you have a very valid point about fuel. I'll certainly consider giving a range from touchdown on leaving the stack if it is for extended vectoring (though usually 40ish miles, never eighty).
apart from the fuel issue, do you have a problem with a 50 mile circuit for 26L, first 25 at FL 70, 220kts, then a standard circuit for the next 25 ? or would you still prefer one more pattern at timba at FL70 ?
How do other pilots feel ?
As a general rule i never reduce an aircraft below min clean until about 12-18 miles unless something's gone wrong.
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Only semi-related to this discussion, but inbound to LGW yesterday mid-afternoon, a reasonable amount of unexpected holding despite not a huge traffic flow......
LGW were still giving "160 knots to 4 DME" but with a wind at 3000 feet of around 270/55-65 knots, the ground speed on final approach was extremely slow.....hence quite wide gaps between arriving / departing traffic.
Surely with strong headwinds on approach it is in the controller's interest to keep the speed up a bit (180 to 4 DME perhaps) to try and keep the ground speed closer to normal, and therefore better spacing. This would also have reduced amount of holding.
What would be the ATC / Operational implications of this?
LGW were still giving "160 knots to 4 DME" but with a wind at 3000 feet of around 270/55-65 knots, the ground speed on final approach was extremely slow.....hence quite wide gaps between arriving / departing traffic.
Surely with strong headwinds on approach it is in the controller's interest to keep the speed up a bit (180 to 4 DME perhaps) to try and keep the ground speed closer to normal, and therefore better spacing. This would also have reduced amount of holding.
What would be the ATC / Operational implications of this?
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In BA we have to be stable (land flap, approach power set, at target speed) by 1000'. 4d at LGW is about 1400'RA, so we would have 400' (vertically) on the glide to lose something like 45kt. Even given the headwind, my little 737 may struggle.
Ccccc...ough
Ccccc...ough
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Wheely, I started the topic to look at what happened when you left the stack with your 'minimums' so it really is NOT about fuel carry, unless you go along the lines that if we are to expect long draggy approaches then our fuel carry MUST increase and we cannot use manufacturers tables for fuel used on descent/approach.
Vertigo, thanks for the reply. Yes FL70 for 25 and then 10 at clean starting to slow up around 12-14 miles would be good. Will vertical/lateral LGW airspace allow this?
Any other pilot injects?
[This message has been edited by BOAC (edited 19 May 2001).]
Vertigo, thanks for the reply. Yes FL70 for 25 and then 10 at clean starting to slow up around 12-14 miles would be good. Will vertical/lateral LGW airspace allow this?
Any other pilot injects?
[This message has been edited by BOAC (edited 19 May 2001).]
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BOAC, I base my approach fuel on an average of 40 track miles from the hold to the arrival runway, so always look to have that plus diversion plus reserves as vectors start off the hold. So personally, as long as the vectoring doesn't exceed 40 miles, I'm happy, but I'd like to know about planned track mileage if we're not talking a standard 24 mile dogleg.
Preference however would be once more round, then standard dogleg rather than extended vectors any day.
See you at crew report!
£6
Preference however would be once more round, then standard dogleg rather than extended vectors any day.
See you at crew report!
£6
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BOAC, you repeat that the reason for starting this thread was holding pattern versus scenic route.
However I think that a valid point such as holding fuel is not out of place on this thread.
One unmentioned point is that there is a recommendation from the CAA around somewhere always to take =>30m holding additional to any field in the London ATC Zone. Seems to have got forgotten recently.
As regards waiting in a pattern or seeing a bit of countryside I prefer the latter. Speed control on final and base are controller items - most of them appreciate what you have to do when going below clean speeds and operate accordingly.
However I think that a valid point such as holding fuel is not out of place on this thread.
One unmentioned point is that there is a recommendation from the CAA around somewhere always to take =>30m holding additional to any field in the London ATC Zone. Seems to have got forgotten recently.
As regards waiting in a pattern or seeing a bit of countryside I prefer the latter. Speed control on final and base are controller items - most of them appreciate what you have to do when going below clean speeds and operate accordingly.
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Few Cloudy - I maintain that this IS about track miles/speed control, NOT holding fuel. There is at least one other active thread on R&N where that matter is discussed at length.
Most pilots plan holding fuel according to experience. (I think the rec. from the CAA was 20 min BTW). I personally need to look at the amount of fuel with which I will LEAVE the holding pattern to start my approach. An EAT will give you this. I then 'estimate' how much I will burn after that. Obviously if the latter burn is significantly higher it will eat into my alternate fuel and could put a comfortable diversion option into the 'anxious' box, unless I know about it and build it in to my reserves calculations.
So, if we can reduce the approach fuel, we can increase the available hold fuel, regardless of whether I have 10/20 or 30 mins extra. Indeed I could hold for an hour or two and still run short on an unexpected extended 'draggy' approach.
Most pilots plan holding fuel according to experience. (I think the rec. from the CAA was 20 min BTW). I personally need to look at the amount of fuel with which I will LEAVE the holding pattern to start my approach. An EAT will give you this. I then 'estimate' how much I will burn after that. Obviously if the latter burn is significantly higher it will eat into my alternate fuel and could put a comfortable diversion option into the 'anxious' box, unless I know about it and build it in to my reserves calculations.
So, if we can reduce the approach fuel, we can increase the available hold fuel, regardless of whether I have 10/20 or 30 mins extra. Indeed I could hold for an hour or two and still run short on an unexpected extended 'draggy' approach.
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Well OK BOAC,
You mention an EAT. If you have that, then the time at which you leave the holding pattern loses its significance, since you burn fuel till touchdown in either case.
The method of calculating fuel burned after leaving the hold only works if the approach is standard, so I reckon that you have hit the nail on the head with the EAT, which works wherever you fly.
You also mention the approach being draggy, if taken on the S tour. I agree that it was in your recent experience but it doesn't have to be. When I see how much traffic the LGW controllers move, compared to say NCE with two runways, I reckon they have it "down" pretty well most of the time.
(Thanks for the 20Mi.note.)
You mention an EAT. If you have that, then the time at which you leave the holding pattern loses its significance, since you burn fuel till touchdown in either case.
The method of calculating fuel burned after leaving the hold only works if the approach is standard, so I reckon that you have hit the nail on the head with the EAT, which works wherever you fly.
You also mention the approach being draggy, if taken on the S tour. I agree that it was in your recent experience but it doesn't have to be. When I see how much traffic the LGW controllers move, compared to say NCE with two runways, I reckon they have it "down" pretty well most of the time.
(Thanks for the 20Mi.note.)
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To bring this back to my original query: can we get one more orbit in the hold and then less track miles/slowing up from TIMBA/WILLO or is it better for ATC to have the flexibility of using longer tracks?
Quite agree with your comments on ATC in the UK. A pleasure to watch/listen to.
[This message has been edited by BOAC (edited 25 May 2001).]
Quite agree with your comments on ATC in the UK. A pleasure to watch/listen to.
[This message has been edited by BOAC (edited 25 May 2001).]
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Ok , Only dealing with the original topic. If everyone wanted a couple of more turns in the hold followed by a shorter arrival pattern then the stacks would build up to a point where they would be infringing on overflying traffic, or more en route holding would be required.
A stack can only be governed using procedural control (ie 1 a/c every thousand feet).
Once clear of the stack and in a radar pattern the controller can then use radar seperation and so can have multiple aircraft at or descending to the same altitude.But the controller must also work within the vertical and lateral confines of their airspace in order to keep you in controlled airspace and out of other airfields traffic.An example of this is at Edinburgh where if you were vectored downwind for 15 miles on runway 06 youd actually be in Glasgows airspace underneath the LANAK hold!
Given the same amount and same mix of traffic you can generally have a relatively tight slow circuit or a faster but larger circuit.
Trying to find a balance between the two is a constant struggle and will never satisfy all pilots or be suitable to all a/c types. This mixed in with Vortex requirements and providing your tower controller with the gaps they need is what makes this job so interesting day in ,day out.
One suggestion I would make is that if you are asked to reduce to 210 when you can remain clean at 220 then say so.It may mean an extra 1/2 mile track distance,it may be granted it may not ,but the controller certainly will consider it.
[This message has been edited by Wheelybin (edited 26 May 2001).]
A stack can only be governed using procedural control (ie 1 a/c every thousand feet).
Once clear of the stack and in a radar pattern the controller can then use radar seperation and so can have multiple aircraft at or descending to the same altitude.But the controller must also work within the vertical and lateral confines of their airspace in order to keep you in controlled airspace and out of other airfields traffic.An example of this is at Edinburgh where if you were vectored downwind for 15 miles on runway 06 youd actually be in Glasgows airspace underneath the LANAK hold!
Given the same amount and same mix of traffic you can generally have a relatively tight slow circuit or a faster but larger circuit.
Trying to find a balance between the two is a constant struggle and will never satisfy all pilots or be suitable to all a/c types. This mixed in with Vortex requirements and providing your tower controller with the gaps they need is what makes this job so interesting day in ,day out.
One suggestion I would make is that if you are asked to reduce to 210 when you can remain clean at 220 then say so.It may mean an extra 1/2 mile track distance,it may be granted it may not ,but the controller certainly will consider it.
[This message has been edited by Wheelybin (edited 26 May 2001).]
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Thanks, Wheely. From what you say it should it be possible then to reduce the vectoring when the stacks are not full? I think we all expect 'bad news' in the rush hours, but if we could plan on expecting a really economic profile outside these that would be great. I fully understand the requirements you are trying to satisfy, but do NOT know how much more difficult it would be to set up the necessary spacing this way. Being specific, how far can you plan ahead for take-off gaps with, say, 08 in use at LGW, to allow short patterns on the ILS and still get a/c airborne with little delay? I appreciate 26 is more of a problem.
Is the use of the BEXIL/LYDD/POMPEY hold for onward shuttle going to make life too difficult in the rush hour? To be kept at, say, 150 at BEXIL and sent on to TIMBA for a steady drop-down and short pattern would be economic. Can anyone remind me please of the upper level limits of these holds?
Few Cloudy
I remember that the '20mins' came from the fact that an ATC 'No delay' means less than 20 mins holding. Or did! We should, presumably, always plan for 20 mins inbound LON airports.
[This message has been edited by BOAC (edited 26 May 2001).]
Is the use of the BEXIL/LYDD/POMPEY hold for onward shuttle going to make life too difficult in the rush hour? To be kept at, say, 150 at BEXIL and sent on to TIMBA for a steady drop-down and short pattern would be economic. Can anyone remind me please of the upper level limits of these holds?
Few Cloudy
I remember that the '20mins' came from the fact that an ATC 'No delay' means less than 20 mins holding. Or did! We should, presumably, always plan for 20 mins inbound LON airports.
[This message has been edited by BOAC (edited 26 May 2001).]
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BOAC
Bexil/Lydd/Pompi (and Bewli/Elder/Sam even for KK too) are last minute solutions when there are no more.
The upper limits at each varies depending on other traffic conditions. Bexil is normally FL190, but only to keep seperated from Tiger hold, so if Tiger isn't being used, the upper limit can be modified by ATC. I remember one morning having A/C holding at Bexil at FL150/160/180/200/220/260/270/280/310!!!
But there was no other traffic through the sector.
Lydd has no limits, and Pompi is FL180 to FL220 to keep seperated from other Lon TMA deps, and Birmingham/Stansted departures which have to achieve FL240+ by MID.
We will only 'en-route' hold at the last resort and it will only make your life slightly better, but hinder others. If we hold at Bexil, then all the LHR in's will be forced down early or vectored off route to the East to avoid the stack. Same problem with Pompi for all STN/LUT ins, and the LHR's again vectored well west.
Solve one problem, create another topic???
Bexil/Lydd/Pompi (and Bewli/Elder/Sam even for KK too) are last minute solutions when there are no more.
The upper limits at each varies depending on other traffic conditions. Bexil is normally FL190, but only to keep seperated from Tiger hold, so if Tiger isn't being used, the upper limit can be modified by ATC. I remember one morning having A/C holding at Bexil at FL150/160/180/200/220/260/270/280/310!!!
But there was no other traffic through the sector.
Lydd has no limits, and Pompi is FL180 to FL220 to keep seperated from other Lon TMA deps, and Birmingham/Stansted departures which have to achieve FL240+ by MID.
We will only 'en-route' hold at the last resort and it will only make your life slightly better, but hinder others. If we hold at Bexil, then all the LHR in's will be forced down early or vectored off route to the East to avoid the stack. Same problem with Pompi for all STN/LUT ins, and the LHR's again vectored well west.
Solve one problem, create another topic???
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Boac,
if you are issued an EAT, it is calculated according to a 'standard' circuit of say 25-30 miles. If you get an extended circuit of say 40-45 miles this will only be because the controller has brought you off the stack 4 or 5 minutes early. How does this eat into your alternate fuel ?
If, as usual, the delay is maybe only 10 minutes, I'll always give you the scenic route. I believe the scenic route to be most benificial for the efficiency of the airport and the airspace.
Do the rest of your fleet prefer to fly another pattern than fly a 45 mile circuit?
On 08 it should be possible to plan departure gaps further ahead, but that very much depends on who is working in the tower and how busy they are. Don't forget we are also committed much earlier to position aircraft downwind from TIMBA, so that extra notice we get from the tower is not always in time for aircraft leaving TIMBA with 15 minutes to touchdown.
if you are issued an EAT, it is calculated according to a 'standard' circuit of say 25-30 miles. If you get an extended circuit of say 40-45 miles this will only be because the controller has brought you off the stack 4 or 5 minutes early. How does this eat into your alternate fuel ?
If, as usual, the delay is maybe only 10 minutes, I'll always give you the scenic route. I believe the scenic route to be most benificial for the efficiency of the airport and the airspace.
Do the rest of your fleet prefer to fly another pattern than fly a 45 mile circuit?
On 08 it should be possible to plan departure gaps further ahead, but that very much depends on who is working in the tower and how busy they are. Don't forget we are also committed much earlier to position aircraft downwind from TIMBA, so that extra notice we get from the tower is not always in time for aircraft leaving TIMBA with 15 minutes to touchdown.
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Thanks to ATC for the comments. Unless I get more response from pilots I cannot answer for the rest!
Vertigo, I guess most people look at fuel to see what they need from commencing approach (ie leaving stack) to landing when judging if you have enough. That gives you your holding capability. To take figures of, say, reserves of 2600kg, we might 'assume' that we will burn 400 kg from the stack to t/down. We would therefore plan available hold on this figure (ie down to 3000kg). If we hold for that time and then burn 700 kg due to extended vectoring, we would have 300 kg less than reserves at t/down. That is the problem.
Vertigo, I guess most people look at fuel to see what they need from commencing approach (ie leaving stack) to landing when judging if you have enough. That gives you your holding capability. To take figures of, say, reserves of 2600kg, we might 'assume' that we will burn 400 kg from the stack to t/down. We would therefore plan available hold on this figure (ie down to 3000kg). If we hold for that time and then burn 700 kg due to extended vectoring, we would have 300 kg less than reserves at t/down. That is the problem.
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Just a few thoughts to make the pool ripple a little perhaps. Have not operated commercially LGW or LHR since 1990, but corporate frequently more recently; little seems to have changed - ATC still doing a grand job as they always have, and lots of aircraft all the time, especially at morning and evening rush-hours. Big machine -2000 kg/hr, small - same in lbs. Early morning or evening rush, carry an extra 45 minutes worth; add the risk (any) of fog- a further 45 minutes. This on top of the extra necessary at busybusy times to cater for the lower levels possible en route. Planned alternate neither the other R/W nor any Londons, as the latters will all probably be liable to similar weather and very busy with everyone else likely to be diverting in these circumstances, with extended routeings resulting there to boot. Sounds ideal and is; keeps the adrenaline level low, grey hair at bay and at the end of the day even if you have burnt as much as 10 percent of the extra 3000 you put on, you have the aircraft and the folk where they should be, so they are more likely to fly with you again, and the next lot can depart on time, or nearly, so they too will be happy, which makes the extra 300 burnt a very good investment! Assuming performance allows it on departure - do it! It used to be called airmanship,it made sense and whatever any Company manual said, it was the commander's decision - and responsibility - to carry prudent additional fuel for the anticipated conditions, which included the aim of getting the folks behind you safely to their desired destination. Surely that still applies, so why even consider minimum fuel in the circumstances outlined? An extra 50 or 100 miles routeing matters not a jot or tittle with enough extra fuel planned for and carried on board. Throw away the sharp pencil immediately!