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-   -   Heathrow Inbounds descending over the top of London City outbounds (https://www.pprune.org/atc-issues/426875-heathrow-inbounds-descending-over-top-london-city-outbounds.html)

Talkdownman 9th Sep 2010 21:52


Originally Posted by Red Four
AIC on revised SIDs nicely tied up to coincide with the release of the AAIB report:
http://www.nats-uk.ead-it.com/aip/cu...2010_34_en.pdf

At last. Years overdue. No, decades, even.
Why is it that nats ignores the concerns of ATCOs on its shop-floor only for its hand to be ultimately forced by the AAIB following investigation of a serious incident. nats has been here before...

250 kts 9th Sep 2010 22:02

It would however make infinite sense not to have the mention of the number 4 in the SID at all. Maybe a DVR 3T would be more approriate and then reiterate 3A in the clearance. DVR 4T and maintain 3A is potentially asking for trouble.

Talkdownman 9th Sep 2010 22:08

How about a 'DVR September Tango' SID....

slip and turn 10th Sep 2010 10:23

From the AAIB report:

NATS reported that, since January 2004, there have been 21 occasions when aircraft departing London City Airport have climbed above the step altitude of 3,000 ft published in the SID. A third of the incidents led to a loss of ATC separation. Evidence from London Stansted Airport showed that removing the step-climb element of the CPT/BUZ SIDs led to a reduction in the number of aircraft that climbed through the first cleared altitude after takeoff. There were 12 ‘level busts’ reported on the SIDs in the 24 months before the end of 2005 when the step-climb was removed. There were 5 level busts in the following three years and seven months.
That's far more history than I had imagined. I take back my somewhat tongue-in-cheek comment about the ANSP moving quickly when it feels the need. Clearly the ANSP felt they knew best at the end of 2005 and didn't feel much disposed to heed a further need until prodded sharply by the regulator.

zkdli 11th Sep 2010 20:43

If only the regulator had prodded hard...
Those of us who have intimate knowledge of the London City SIDs and the efforts that that have gone in to trying to make them safer over the years would have appreciated little more support from the regulator over this one.

For those of you speculating about the three thousand foot stop, it was instituted several years ago (i think after a series of level busts in 2005) to reduce the risk of continuing level busts in the area. Until 2009 it was considered to have been a reasonable solution.
To the people who think that it is only business aviation that causes the problem think again - FK50s might only climb at 1500fpm but they also used to regularly bust the 3,000ft step. The other issue was the level busts by inbounds, that is why there are so many new procedures for the two routes - ask a BA pilot what he thinks about the "box":hmm:

dive in to bunker to await the incoming!

Mister Geezer 11th Sep 2010 22:45

The weakest link is not the airspace infrastructure nor the ATS provider but rather the crews. There is a massive spectrum of training standards, abilities of crew members and quality of operational control from commercial operators from all over the world. To say that the London TMA is a multi-cultural environment is perhaps a slight understatement!

Then you have the corporate aviation industry which in some states has little in the way of any tangible oversight or regulation whatsoever.

With the THY B773 incident, I personally thought it was very telling that the commander was in fact a Line Training Captain and he used non standard TCAS R/T and did not follow the RA when he first heard it. Now if that is from an established flag carrier.... well need I say more?

The sad reality is that the difference between standards on the flight deck in the UK and Europe is in some cases a world away from what you can and indeed will see in some other states further afield. You can have a multitude of ATC procedures, initiatives and ideas, yet you still have to rely on the guy in the flight deck doing his job properly.

slip and turn 11th Sep 2010 23:36


Originally Posted by Mister Geezer
The weakest link is not the airspace infrastructure nor the ATS provider but rather the crews.

I heard once that the largest department at the ATS provider is 'Human Factors'. Why? Because the risks associated with inviting the lowest common denominator of your weakest link into their world have to be managed and minimised or in some troublesome scenarios zero-ed out by design (by the ATS provider).

DFC 13th Sep 2010 13:30


Just imagine.... if in every TMA and airway over Europe, when climbing and descending aircraft were likely to get within 1000 ft, they built in an extra 1000 ft.... That would be like saying the standard vertical separation will now be 2000 ft..
Ah but how often do we experience a level off that is required to be made before the completion of the noise abatement procedure????

On the noise abatement we do not reduce the rate of climb to the ideal of 500 - 1000 ft per min with 1000ft to go for obvious reasons?

Therefore it should be obvious that if one is going to cross an aircraft 1000ft above an aircraft on a noise abatement departure, the rate of climb of the lower might be a bit on the high side for a simple 1000ft tcas (and STCA) free pass!

The "Maintain 3000ft" in city clearances is the most misunderstood example that I have come across. 50% of people I have operated with have said " as per the chart" and without being told otherwise would have climbed at the appropriate point to 4000ft. That is not what ATC expected.

I think that it is amazing that so few problems have occurred!!

Based on what was going on in terms of non-standard clearance procedures, early level-offs, traffic descending on top it is pure luck that there were not far more problems.

As for "Cleared DVR xxx Maintain 3000ft". This is not taking a flight off the SID. It is simply repeating what is part of the SID.

I believe that if the SID is to be cancelled then a full clearance is to be provided i.e. something like "climb straight ahead to 1.5dme and then turn right to establish outbound on the LON xxx radial climb to 3000ft.

What has probably saved the day on many occasions is that the airport operator requires that all crews receive initial and regular refresher training before being authorised to operate into the airport and while a lot of time is spent on the arrival aspects, there is some time devoted to departures and the "local practice of wanting flights to maintain 3000ft "full stop" on the SID.

Gulfstreamaviator 13th Sep 2010 14:00

Is Luton just as bad these days
 
Luton used to be the nightmare departure due to the STEP climb, and IMHO a very unclear ATC clearance.

Is it still as bad, or has City taken the lead.

Glf

DFC 13th Sep 2010 14:14

Luton has the step climb and quite a few turns and various legs that can all happen a bit quickly for those not familiar and who let the speed rush away a bit but aircraft are cleared on the SID and are required to follow the SID vertical profile with no local non-standard revisions.

The problem is that

day 1 - Luton - stepped climb - follow the steps or there will be big trouble

day 2 - City - stepped climb - don't follow the steps because if you do there will be trouble.

day 3 - Northolt - stepped climb - follow the steps or there will be trouble.

Now which is the odd one out?

error_401 18th Sep 2010 10:12

It's on the ATIS of LCY anyways not to climb above 3000 feet after departure.

On the departure I think it's sensible of the crews to level off at 3000 unless cleared otherwise. Normally we reach 3000 even before intercepting the LHR radial eastwards.

Watching the TCAS and reducing rate of climb when reaching 3000 helps as well. I normally keep it at or below 1000 ft/min in the terminal area.

When departing LCY I use V/S 1'000 ft/min for the step climbs unless in the DVR area when cleared to a higher level. This reduces the risk of TCAS triggers with opposite descending traffic. Inbound or outbound this greatly helps. The lower rate also gives more time to monitor.

Talkdownman 18th Sep 2010 11:54


Originally Posted by error_401
On the departure I think it's sensible of the crews to level off at 3000 unless cleared otherwise.

Sensible? It is a Requirement...

Over+Out 18th Sep 2010 13:45

Did I read that the SID's are changing to ''maintain 3000 ft''
Can anyone confirm this please?

Talkdownman 18th Sep 2010 13:54

Over+Out, do you read? Over....

Over+Out 18th Sep 2010 16:57

Thanks for taking the time to find the answer


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