Minimum Separation on Approach at LHR
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Minimum Separation on Approach at LHR
Hi all
I've learned that while the minimum separation of aircraft in UK airspace is usually 3nm, in the LHR area this changed not so long ago to 2.5nm. Why and when was this done, and is it wise? To increase / help maintain the present landing rate -- I read somewhere that typically LHR operates to 98.5% capacity (hence the nightmare scenarios we see on tv every time it's a bit foggy).
Any thoughts very welcome.
Best wishes
Ian Shoesmith
BBC News
I've learned that while the minimum separation of aircraft in UK airspace is usually 3nm, in the LHR area this changed not so long ago to 2.5nm. Why and when was this done, and is it wise? To increase / help maintain the present landing rate -- I read somewhere that typically LHR operates to 98.5% capacity (hence the nightmare scenarios we see on tv every time it's a bit foggy).
Any thoughts very welcome.
Best wishes
Ian Shoesmith
BBC News
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The 2.5nm approach spacing at Heathrow (and elsewhere?) has been in use for many years. I retired nearly 6 years ago and it was in force long before that so it has probably been in force for 10 years? It may only be used under certain conditions and between particular types of aircraft and only on final approach. Not every flight is subject to 2.5nm spacing. The simple reason for it is to achieve greater runway utilisation.
If on an average day LHR operates at 98.5% capacity, then a day with stronger than average wind will quickly create delays. An extra 10 mph headwind loses 10 miles of available approach spacing or about 3 landigs every hour - something like a 7% reduction in available landing capacity, with stronger winds being even worse. There is no spare capacity to absorb this, so it turns in to large for aircraft waiting to go to LHR and for those holding in the busy London skies wanting to land there. The reduction in arrival spacing can go some way to reducing this delay, but only under strict weather criteria which allow the following pilot to see what is 2.5 nm ahead of him. It is specified that there should be no increase in missed approaches as a result of the use of this procedure, so by implication it is only really used when ther is a bit of a headwind and it is not used to increase declared arrival capacity.
Other airports are also allowed to use the procedure, but it is usually less essential as they tend not to operate at full capacity and most other UK airports use the same runway for arrivals and departures so that inound spacing can be reduced from 6 to 5 miles still allowing a departure to take off in between.
Glad to see someone from the BBC taking an interest and not just making it up like many media types seem to.
Other airports are also allowed to use the procedure, but it is usually less essential as they tend not to operate at full capacity and most other UK airports use the same runway for arrivals and departures so that inound spacing can be reduced from 6 to 5 miles still allowing a departure to take off in between.
Glad to see someone from the BBC taking an interest and not just making it up like many media types seem to.
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Alt Flaps
I often despair of the inability of some journalists to get facts correct, or to even check those facts. Not just restricted to the journos writing the piece, but the sub editors as well.
To be fair to Ian, he is always upfront about who he is and what his intentions are. There are plenty 'professionals' on here who whinge about the professionalism of journalists, no doubt you are amongst this number.
Surely even you can see how contradictory it is to lambast the ethics of journalists who do not write factually (many lurk on PPRuNe pretending to be something they are not), yet give a journalist like Ian (who is trying to be upfront and honest) a hard time?
You can't have it both ways!
I often despair of the inability of some journalists to get facts correct, or to even check those facts. Not just restricted to the journos writing the piece, but the sub editors as well.
To be fair to Ian, he is always upfront about who he is and what his intentions are. There are plenty 'professionals' on here who whinge about the professionalism of journalists, no doubt you are amongst this number.
Surely even you can see how contradictory it is to lambast the ethics of journalists who do not write factually (many lurk on PPRuNe pretending to be something they are not), yet give a journalist like Ian (who is trying to be upfront and honest) a hard time?
You can't have it both ways!
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HD - I think you are refering to the 2.5nm spacing on final approach but Ian is talking about the 2.5nm separation (2.5nm radar separation within 20nm from touchdown)which I believe has not been in force as long.
Why and when was this done, and is it wise?
a)3 miles and tangential tracks or even head on at a closing speed of up to 10 miles a minute,
or
b) 2.5 miles going the same direction at the same speed with a closing speed of 0?
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I'll try that again then ...
I posted earlier in response to Mr Shoesmith's post. It seems that I have brought the wrath of 'mod' down upon me, because my post was deleted.
This forum is for threads that specifically affect the working lives of professional pilots.
I took great issue with Mr Shoesmiths attempt to extract and publish the names of the crew directly after the BA 777 incidient last month.
He may be 'up front and honest
', but that doesn't alter the fact that had he succeeded, the lives of those pilots (and possibly their families) would have been made significantly more difficult in those first couple of days.
Now forgive me here, but I am a professional pilot, and I will continue to look out for my colleagues where I can ...
Moderator, is this post acceptable to you, or would you like me to start a seperate thread on the topic ?
I posted earlier in response to Mr Shoesmith's post. It seems that I have brought the wrath of 'mod' down upon me, because my post was deleted.
This forum is for threads that specifically affect the working lives of professional pilots.
I took great issue with Mr Shoesmiths attempt to extract and publish the names of the crew directly after the BA 777 incidient last month.
He may be 'up front and honest
', but that doesn't alter the fact that had he succeeded, the lives of those pilots (and possibly their families) would have been made significantly more difficult in those first couple of days.Now forgive me here, but I am a professional pilot, and I will continue to look out for my colleagues where I can ...
Moderator, is this post acceptable to you, or would you like me to start a seperate thread on the topic ?
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This forum is for threads that specifically affect the working lives of professional pilots.
We tolerate journos to some extent here, and even pilots
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shoey 1976 - journo or not, asked a perfectly reasonable question.
I suppose you'll be blaming him for making them go to the Sunday papers to sell their stories when there were a few shekels in it, will you?
A professional pilot you may be, but the question wasn't one for which a professional pilot's opinion was sought since it's not a professional pilots job to provide separation.
As for your two colleagues, they seemed capable of handling much more than a journalists enquiry last month, both during the incident, and after it as well.
It's doubtful they need anyone's 'protection'.
As for the 2.5NM separation, sounds good. Wonder if we can get that into our MATS Pt2?
I took great issue with Mr Shoesmith's attempt to extract and publish the names of the crew directly after..........
I am a professional pilot, and I will continue to look out for my colleagues where I can.
As for your two colleagues, they seemed capable of handling much more than a journalists enquiry last month, both during the incident, and after it as well.
It's doubtful they need anyone's 'protection'.
As for the 2.5NM separation, sounds good. Wonder if we can get that into our MATS Pt2?
Good one Spitoon
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Talking about separations, how do you answer this. When I was a controller the MATS Pt 1 stated that for a light aircraft to follow a heavy aircraft on final approach the vortex spacing has to be 8 miles. However for an en route or intermediate approach a light can be 5 miles behind a heavy. Doesn't this contradict its self. How can you have 2 different rules.
Fly a lot into EGLL & EGKK now and the vortex spacings are not a problem, but again my question is how does the MATS Pt1 state different rules and EGLL have different rules.
Fly a lot into EGLL & EGKK now and the vortex spacings are not a problem, but again my question is how does the MATS Pt1 state different rules and EGLL have different rules.
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Greater/stronger vortices are generated in landing configuration than in cruise config.
The variations from national procedures are described in the unit MATS Part 2 (and, in some cases, will be included in the AIP) and will be subject to approval by the regulator. Approval will only be given if a suitable safety case is produced. Well, that's the theory anyway.....
The variations from national procedures are described in the unit MATS Part 2 (and, in some cases, will be included in the AIP) and will be subject to approval by the regulator. Approval will only be given if a suitable safety case is produced. Well, that's the theory anyway.....
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Before the change:
LL has a 3nm spacing requirement, which is the same as the minimum radar separation, which can decrease to 2.5nm when certain conditions (daylight only, and good weather conditions etc) exist.
After the change:
LL still has a 3nm spacing requirement, but now the minimum radar separation is 2.5nm on final approach, bringing LL into line with ICAO guidelines on radar separation on final approach.
LL has a 3nm spacing requirement, which is the same as the minimum radar separation, which can decrease to 2.5nm when certain conditions (daylight only, and good weather conditions etc) exist.
After the change:
LL still has a 3nm spacing requirement, but now the minimum radar separation is 2.5nm on final approach, bringing LL into line with ICAO guidelines on radar separation on final approach.
why you bother with the extra 1/2 mile
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I've got a question for you guys! Doesn't quite come under seperation but its the closest thread to it...B757 at FL 300.... Dash 8 at FL 290. The 757 is directly above the Dash 8. As you can see it is seperated by the required 1000 feet. What is wrong with this scenario? Question is open to everyone!!