B747forever From United States of America, joined May 2007, 16598 posts, RR: 11 Posted (4 years 2 months 4 weeks 1 day 1 hour ago) and read 8036 times:
I have a few questions regarding the different holding patterns at LHR.
Where is each holding pattern located? (my understanding is that there are 4 holding patterns that LHR has in use)
How long is each holding pattern?
It seems almost that every a/c arriving to LHR takes at least one lap around the pattern (have happened on all of my flights, and I have flown into LHR many times). How many of the arrivals get into the pattern and for how long usually. Any particular hours where the risk to get into the pattern is most likely?
If a flight arrives from the U.S, which holding pattern is the a/c most likely to use?
VV701 From United Kingdom, joined Aug 2005, 6675 posts, RR: 17 Reply 1, posted (4 years 2 months 4 weeks 1 day 1 hour ago) and read 7999 times:
There are four LHR stacks each located over a VOR beacon. The Bovingdon stack is in Hertfordshire and is located north west of London. This is the stack that an aircraft crossing the North Atlantic is most likely to be directed to. The stack to the south west of London is over Ockham in Surrey. This stack may also be used for arrivals from North America.
There are stacks to the south east of London at the World War II Battle of Britain airfield at Biggin Hill in Kent and to the north east over Lambourne, Essex.
Each stack stretches up from 7,000 to 13,000 feet and can accept up to 7 aircraft 'stacked' at 1,000 foot vertical intervals.
Three factors determine which stack an aircraft is likely to be directed to:
1. Its direction of approach to the London area
2. The aircraft size. (Since LHR is slot constrained and since a 'heavy' can follow another 'heavy' more closely than a 'medium' or 'light' can follow a heavy (due to wake turbulance) ATC may guide all heavies into stacks to enable them to land two, three, four or sometimes more heavies consecutively. This minimises the gaps between aircraft and maximises the efficiently of runway use.
3. Whether or not the logical stack (from a diection of approach perspective) is full or nearly full.
Heathrow is slot bound nearly all day. According to Airport Coordination Ltd who issue and monitor the use of slots at all slot controlled airports in the UK and the Republic of Ireland, the first available unused arrival slot on a weekday in the current winter timetable is between 1540 and 1550 hrs (3.40 to 3.50 pm). (With the night curfew there are a total of 653 arrival slots currently available each day. The number per hour varies from 33 to 41 (with most close to 40 to 41). I believe this variability may reflect the differing aircraft sizes and therefore the required spacing on final approach.
However after 2045 hrs (8.45 pm) the arrival slot situation does ease. So if you need to stay clear of an LHR stack select a flight arriving between 2100 and 2330 hrs (9.00 to 11.30 pm). At other times you are likely to go into a stack at least until LHR (hopefully) gets its third runway.
VV701 From United Kingdom, joined Aug 2005, 6675 posts, RR: 17 Reply 2, posted (4 years 2 months 4 weeks 16 hours ago) and read 7822 times:
I misread the Airport Co-ordination Ltd chart when I said
Quoting VV701 (Reply 1): the first available unused arrival slot on a weekday in the current winter timetable is between 1540 and 1550 hrs (3.40 to 3.50 pm)
What I should have said is that 'the first available unused arrival slot in the current winter timetable is on a Saturday between 1500 and 1600 hrs'. I should have gone on to say that 'on weekdays there are no available unused arrival slots until late in the evening'.
Nope. There are many more. BIG/OCK/LAM/BNN are only the 4 inner stacks closest to EGLL. Each of the 4 main stacks have backups in case any of the VORs are broken. Each of the backups is at the same place as the original hold but references a different VOR. So they fly different inbound and outbound headings. There are also outer stacks in case the inner ones are at capacity.
For example if BIG is u/s, the hold becomes WEALD which is a waypoint at exactly the same place as BIG but references DET or BNN. If BIG is full, aircraft can be held at TIGER or LYD.
It is also possible to swap aircraft from one stack to another - there are procedures in place to go from LAM to BIG/BNN/OCK, and from BIG to OCK.
RP TPA From United States of America, joined Oct 1999, 831 posts, RR: 0 Reply 10, posted (4 years 2 months 4 weeks 7 hours ago) and read 7116 times:
Quoting Theginge (Reply 9): Thats not a hold, that would be when you were turning on to final approach. There are no holds over central London. The Bovingdon hold is about 20 miles to the North West of central London.
Hmmmmm........I seem to remember doing at least 2-3 full circles at that point, while looking down and seeing those landmarks. Perhaps my memory is fading.
LHR27C From United Kingdom, joined Aug 2004, 1279 posts, RR: 18 Reply 12, posted (4 years 2 months 4 weeks 6 hours ago) and read 7018 times:
Quoting RP TPA (Reply 10): Hmmmmm........I seem to remember doing at least 2-3 full circles at that point, while looking down and seeing those landmarks. Perhaps my memory is fading.
No chance I'm afraid, for obvious reasons there are no holding patterns over central London, and operationally speaking it wouldn't make sense either being on the extended centerline of LHR/LCY runways. If coming off BNN (and even more so from LAM), you can feel like you are doing almost a 180 at that point but it's just to establish on the ILS.
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Spencer From United Kingdom, joined Apr 2004, 1624 posts, RR: 19 Reply 13, posted (4 years 2 months 4 weeks 6 hours ago) and read 6998 times:
Quoting RP TPA (Reply 8): The last time I flew into LHR (from Toronto), we circled over the London Eye/Houses of Parliament area.. Was that the Bovingdon hold?
More than likely the LAM hold, although I'm surprised you didn't hold at BNN. Most of NE London can be seen from LAM, including the London Eye. Coming off LAM you'd fly "up" the Thames basically over LCY and then the city.
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Another question, is LHR the #1 airport in most usage of holding patterns?
It is in my experience. I have almost never arrived at LHR without spending from 10 to 30 minutes in a holding pattern. That is almost unheard of at all other major European airports. In fact, I can't remember any holds at any airports other than LHR apart from those that might be due to some unusual weather issues.
The fuel wasted, and resulting carbon emissions/pollution, by aircraft in LHR holding patterns must be incredible. A month or two ago I was on a BA flight GVA-LHR where the one hour flight was was followed by almost 30 minutes going around in circles. The total time in the hold turned out to be twice as long as originally estimated by the captain. And the weather was perfectly clear and sunny that day.
Ba97 From Canada, joined Apr 2004, 377 posts, RR: 0 Reply 16, posted (4 years 2 months 3 weeks 6 days 23 hours ago) and read 6833 times:
On the Atlantic flights we sometimes arrive 30 or so minutes early to the LHR area. We joke that there is a race across the Atlantic and first there avoids a hold more than 1 lap. When we arrive "on time" or I am on a later flight, I fully expect to do 3 laps. I expect a flight plan says when you expect to arrive. If you arrive early, do you just drop into the pattern or do you sit in an outside hold waiting for a gap to be created to accommodate your out of sequence arrival?
Healthrow seems to be the one airport I always am in a hold, is there something unique about its operations other than volume (e.g. the % of heavy aircraft). Even arriving in LGA or Chicago I do not experience this (leaving Chicago is another story)
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Cloudyapple From Hong Kong, joined Jul 2005, 2425 posts, RR: 9 Reply 17, posted (4 years 2 months 3 weeks 6 days 21 hours ago) and read 6803 times:
It the way we operate and it's the most efficient way to run the airport and this maximizes runway capacity. The stacks act as reservoirs so the intermediate controllers have always a number of aircraft of differing wake turbulence categories to select from to construct a sequence with the least spacing and most movements.
Quoting Ba97 (Reply 16): Healthrow seems to be the one airport I always am in a hold, is there something unique about its operations other than volume (e.g. the % of heavy aircraft). Even arriving in LGA or Chicago I do not experience this (leaving Chicago is another story)
If you are pushing maximum movements through limited infrastructure you always end up having delays. It's a fact of life. It's just a matter of where the delay is absorbed.
In the US they hold aircraft at the departure airport and enroute. In the UK we hold them in stacks close-field. The difference being, with all of the US being under the the FAA, they can implement ground stops much easier than the fragmented Europe. Most of the flights that arrive into Heathrow are from outside the UK. We can't call Paris up to ask them to hold aircraft X so that it arrives at exactly the time we want it to. It's even more difficult to call up Tokyo 10 hours before arrival to ask them to depart at exactly the right time to arrive with no delay. Things do change enroute.
We have run Heathrow for many many years and this is the most efficient way to run it at 100% capacity all the time.
Quoting Viscount724 (Reply 15): The fuel wasted, and resulting carbon emissions/pollution, by aircraft in LHR holding patterns must be incredible.
Balance that with the alternative which is to ask each flight to ground hold to arrive exactly on time (to the second) which is not possible. NATS is renowned for maximizing capacity. Heathrow runs 90+ movements hourly on 2 runways and the maximum we have ever done is 98. There is a way we achieve this. Which other airport can match this?
There are initiatives to use other methods to reduce holding without compromising the delivery the moments but I won't elaborate them here.
louA340 From Canada, joined Oct 2005, 378 posts, RR: 0 Reply 19, posted (1 year 2 weeks 5 days 23 hours ago) and read 3385 times:
Quoting Cloudyapple (Reply 17): The difference being, with all of the US being under the the FAA, they can implement ground stops much easier than the fragmented Europe
Does the FAA have agreements with Nav Canada as well, because I know at YYZ, during peak afternoon times, I usually see the flights heading to the NYC area do a ground hold at a designated area just short of the runway before departing.
emalad From United Kingdom, joined May 2006, 443 posts, RR: 0 Reply 21, posted (1 year 2 weeks 3 days 13 hours ago) and read 3002 times:
When flying back from KUL on MH2, we were lucky enough to fly straight in. I have flown several times between BCN and LHR on BA and never had to hold, these being afternoon arrivals into LHR. The worst hold I ever had was on FR into STN, I physically felt sick as we were circling for what seemed ages, then flew parallel with the airport and came in. I suppose I have just been lucky at LHR