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-   -   London Airport SIDs (https://www.pprune.org/atc-issues/546382-london-airport-sids.html)

boilerbill 26th Aug 2014 23:48

London Airport SIDs
 
I've noticed that the SIDs out of most of the London airports restrict departing aircraft to a relatively low altitude and a low airspeed for quite some time/distance. For example, all of the EGLL SIDs top out at 5000 ft or 6000 ft despite the fact that they cover up to 60 or 70 miles of lateral distance. I know there must be airspace limits to allow the traffic from all these airports to mix safely, but it seems a bit excessive to keep an airliner departing EGLL or EGKK to still be flying at 6000 ft/250 KIAS as they pass over the DVR VOR. Are these SIDs usually flown in their entirety, or is it common for ATC to approve an early release to enroute altitudes and speeds?

chevvron 27th Aug 2014 00:45

Heathrow Director may come along and explain it better, but all departures are designed so traffic procedurally ie non radar remains below arriving traffic. On a DVR departure for instance, traffic crosses below arrivals routing to OCK VOR which normally descends to FL70 depending on the altimeter setting. The 250 kt speed limit is normally cancelled by the departures controller as early as possible and the aircraft is climbed above the SID altitude as soon as it is clear of the arrival pattern.
It's even more complicated with Heathrow landing on 09L as BCN departures are vectored parallel to arrivals from OCK and BIG and climbed above the arrivals by the Heathrow Director so you get two tracks of aircraft parallel, one descending and the other climbing.

Juggler25 27th Aug 2014 06:03

I've never seen a LL or KK departure still at the SID levels overhead Dover. They are usually above FL240 by this point and being transferred to Maastricht for higher.

The worst affected SIDS are SS departures via Dover as they get stuck underneath the LL arrivals from the east and then are usually climbed underneath LL and KK departures routeing the same way. So are frequently still at FL80 passing Detling. However, this is all set to change when LAMP comes in supposedly late next year (I think).

renard 27th Aug 2014 09:24

I fly out of London City and stop altitude is 3000'. We normally do stop at 3000' on the BPK departures but soon get climbed and would expect to be at 6000' at BPK where the SID ends.

On DVR and LYD departures we soon get to 6000' and might still be there at DET, but would expect to be about FL200 by DVR or LYD.

When we fly the ALKIN3F arrival, we have to be FL100 at WAFFU, about 100nm track miles from touchdown....(It is very busy airspace)

boilerbill 27th Aug 2014 22:59

Many thanks for the information. I had assumed the procedures were drawn with the worst possible scenario in mind; thankfully, that WPS rarely happens. As a private pilot, I'm always very interested in what's happening when I fly commercially. I've passed through both EGLL and EGKK many times over the years and I can't recall any departures that seemed out of the ordinary. I'll be back to EGLL in 3 weeks when we connect there from an overnight BA flight out of KJFK onto a late morning service to Milan Linate. I'll have a chance to experience a southeast departure then. I wish BA A320's had Concorde-style Marilake displays. :)

HEATHROW DIRECTOR 28th Aug 2014 09:15

I was a Heathrow controller for most of my life and never saw an outbound from Heathrow cross DVR at 6000ft!! The TMA controllers do their utmost to climb outbounds ASAP and they do a remarkable job in very congested airspace.

zonoma 28th Aug 2014 09:27

It is all worst case senario, and also for RTF failure procedures to ensure the departing aircraft are well clear of the stacks/inbound flows before commencing climb as per the failure procedure. As mentioned above, LAMP will begin to be introduced (3 or 4 stage implementation) to improve this. At present, all aircraft have to fuel up for the worst case senario, a heavy going longhaul on a DVR SID burns ridiculous amounts of fuel during the departure - carrying extra fuel just to be able to carry the worst case senario fuel. I've seen the figures but cannot remember exactly so not going to guess, but it will be millions saved in fuel cost PER ROUTE each year (based on a full B747 to Singapore departing on the DVR SID every day off 27L/R). Stage 1a of LAMP introduces point merge approaches to Gatwick and London City & will improve departure routes from London City, Southend, Biggin Hill, Standsted & Luton. The knock on effect is more possibility for earlier climb departing Heathrow & Gatwick. I believe the SIDs off LL & KK will be shortened to end at DET too so the fuel carry will be slightly improved. It's a long & gradual process but eventually (2019??) all the changes will have been made & the much better profiles introduced.

EastofKoksy 1st Sep 2014 07:23

Clearly whatever the airspace design, arrivals have to cross departures somewhere. Choosing the least inconvenient place is of course the key.

As a former airspace planner I hope LAMP will be successful. However the recent rumpus over the Gatwick ADNID trial gives an indication of the resistance to changes in flight paths, however 'green' they might be, from those living below them. A clash between what is technically possible and what is politically allowable has always existed but is more severe than in the past. This could end up scuppering significant parts of LAMP. I hope the various stages are not too inter-dependent.

Regarding fuel savings that airlines might achieve by earlier climbs. Our flight deck friends might contradict me on this but I suggest an airline does not make its fuel calculations to the degree of detail of will a flight departing Heathrow get continuous climb or will it have to wait until Detling before leaving 6000'.

Jwscud 1st Sep 2014 09:18

They're already mucking about, as the SS SIDs now go to DET and LYD, but not as far as DVR (never get much past DET without a heading anyway).

I quite like heading down to DET at FL70/80 as you get a cracking view of London and the Thames estuary on a nice day.

soaringhigh650 1st Sep 2014 09:27

I'm a huge supporter of earlier climbs.

When you can get large, high-perforamnce aircraft to climb as high and quickly as possible after departure you can route them in various ways without affecting anyone on the ground.

Also you free up low level airspace for lower performance aircraft such as light GA types to use.

HEATHROW DIRECTOR 1st Sep 2014 11:46

SH650. But what about the traffic above preventing climbs?

Cough 1st Sep 2014 17:59

HD - Newer RNAV SIDS are slowly creeping in which dodge the protected airspace for the holds. On a MID stopping at 6000' was normal (unless you get to 4000' early so a heading could be issued...). On the newer DOKEN SIDS FL100 or even FL170 is often the first clearance, without a heading which is good for workload (for everybody!)

PS. I've hit DVR at FL80 once. The ATC chap controlling me DID apologise and I could see on the TCAS display multiple reasons why climbing wasn't an option. We got to cruise level of 330 45 mins after departure! (but I have to add thats a long way from normal!)

zonoma 1st Sep 2014 21:28

EastofKoksy - our airline friends DO make their fuel calculations to maintain 6000ft til DET/DVR before being cleared higher. This is a major driver behind the LAMP project as the most inefficient phase of flight through the London airspace at the moment is the initial departure phase. The eventual idea is for aircraft to depart LL/KK/SS/GW climbing to something in the region of 10000ft on the SID, making huge cost saving (fuel) benefits. The stacks will be reduced to two for Heathrow and will be higher and farther out giving further benefits to incoming traffic too.

Not Long Now 2nd Sep 2014 08:13

OK, slightly off topic but...
Apparently raising the TA is a huge 'facilitator' in LAMP, and LAMP is pretty much screwed without it, primarily because you cannot have a SID which ends at a flight level. Given the huge amount of work and changes required for the TA change, why not try to change the regulations that say you can't fly a SID to a FL??

zonoma 2nd Sep 2014 09:06

Agree Not Long Now, and it has been looked at several times. As with these things, there already are SIDs that finish with a FL (cannot remember where, EGNX??) however so far the CAA have rejected the idea for the London TMA. I cannot remember all the reasons why but will attempt to reraise the question and find out. One reason that was certainly raised was when the aircraft will switch to 1013, obviously the differences between UK and other places already exist so a safety case has enough clout with just that on its own.

soaringhigh650 2nd Sep 2014 09:22


But what about the traffic above preventing climbs?
Then what are they doing there in the first place? All runways but Stanstead are East-West facing?

If you take Stanstead out of the equation, when winds are from the west all traffic arrives from the east and takes off towards the west.

So no one should be blocking anyone on climbout so why can't one sort out departure crossings (i.e. Luton southbound departures vs. Heathrow northbound departures) way up at 18,000ft+?

Or are you saying there could be easterly winds at Heathrow but westerly winds at London City?

jmmoric 2nd Sep 2014 09:33


Then what are they doing there in the first place?
I really haven't got a good answer to this one :D

ATCO Two 2nd Sep 2014 10:18

Actually, it happens fairly often that there are different wind directions at EGLL and EGLC. Also EGLL operates preferential westerlies with a slight tailwind, whereas EGLC is very wind sensitive and frequent changes of runway end occur regularly.

The Many Tentacles 2nd Sep 2014 15:50


Then what are they doing there in the first place?
Seriously??

OK, let's suppose a Heathrow departure leaves 27L going via DVR so it comes off and makes a turn to the left and heads towards DVR. It can climb quite happily except for the Gatwick departure off 26 that wants to go North or towards Clacton, or the City outbound that wants to go South or the Luton one that's going South In your scenario, one of these aircraft would have to fly miles out of its way to avoid the other to allow them to keep climbing and cross each other at 18000ft or so. And that's before you take into account anything out of Farnborough, Biggin, Northolt etc etc

I don't think you can make any sort of statement about the LTMA like yours without looking like you know nothing about what is going on there. I know you seem to have an axe to grind with the way ATC is done in this country, but until you understand it properly I'd suggest you stop grinding

Defruiter 3rd Sep 2014 21:52

As ATCO two mentioned, the wind direction at EGLC and EGLL can quite often (several times a month on average) be blowing from completely opposite directions. It has a lot to do with the river and the tall buildings near to the docks. It tends to be more 09 vs 27L/R than 27 vs 09L/R. The wind direction at City is more critical than any other airport in the TMA due to the steep approach and short runway. Most aircraft can't take as much of a tailwind as they would elsewhere, and certain types and operators can not take any at all. It isn't unusual to switch runway 5 or 6 times in an hour when the wind is from the north or south.

Runway directions across the entire TMA also vary between each airport fairly often. It's quite surprising how different wind conditions can be across such a relatively small distance. Procedures have to work for all mixtures of runway direction in use.


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