Gatwick spacing

[stonethrower]

Can someone explain to me how Gatwock achieves such a high runway rate per hour on one runway? Is it a one in one out system with standardized arrival gap spacing? I'm doing some research and any assistance and or advice on similar single runway airports would be warmly welcomed.
Regards

[kcockayne]

I would assume that the Radar Controller, at Swanwick, separates approaching traffic with an agreed spacing (agreed with the Gatwick TWR Controller) designed to accommodate the requirement to fit departing a/c into the runway usage. This spacing would be based on a "standard gap" & be subject to alteration at the request of Gatwick TWR when necessary (due to the demand of heavier levels of departing traffic). Whether there is anything more intricate than that involved, I don't know.

[kcockayne]

I should add , the obvious comment, that it is a VERY slick operation ! Well done everyone concerned.

[chevvron]

The NATS controllers at Gatwick have 'honed' things down finely, I have been at 4 miles and they have launched 2 departures before we were cleared to land.
Whether the new ANSP will be as good remains to be seen although I believe some NATS controllers will be staying on.

[T250]

Whether the new ANSP will be as good remains to be seen although I believe some NATS controllers will be staying on.

What a peculiar comment to make.

Considering that the approach radar services will continue to be provided by NATS from Swanwick, these should remain the same.

Only thing changing is half a dozen ATCOs in the VCR, as most NATS controllers are in fact staying on. Where else do they have to go :hmm::p

[Nitty Gritty]

Beyond the reasons stated previously, APP arrival separation and TWR dexterity, I suppose two other key elements are the design of procedures that contribute to reduce the Runway Occupancy Time and the rate of pilot compliance with these procedures.

You can find these local regulations at EGKK´s AIP [AD 2-EGKK-1: 2.20 6-Use of Runways h)].

[M609]

Does Gatwick require to have full RWY length separation between departing and arriving aircraft?

[kcockayne]

I should not think so. If you had to wait until you had the full length of the runway available for landing traffic (behind a departing) that would negate the whole point of running things as tight as possible.

[HEATHROW DIRECTOR]

<<Does Gatwick require to have full RWY length separation between departing and arriving aircraft?>>

Does anywhere?

[M609]

Yes, that is ICAO standard (PANS-ATM 7.10.1, as I think you know ;) ) Some regulators are scared of the provisions in 7.11 for some reason......

[Ratatat]

Does Gatwick require to have full RWY length separation between departing and arriving aircraft?

Arriving aircraft are not to have crossed the start of the runway until departure is airborne.
Or
When using "after the departing, cleared to land" the departure must be 2000m down the runway and airborne, or, 2500m if still on the ground, before arrival crosses the threshold.

[Ratatat]

What a peculiar comment to make.

Considering that the approach radar services will continue to be provided by NATS from Swanwick, these should remain the same.

Only thing changing is half a dozen ATCOs in the VCR, as most NATS controllers are in fact staying on. Where else do they have to go :hmm::p

From memory 11 controllers moving onto various NATS units or other business areas. These are staying on as secondees whilst ANS recruits are trained up to replace them. 4 retiring and staying as secondees until retirement.
Service from the Tower atcos will continue as it is today. New recruits being trained by current staff so no reason to think it won't stay the same.

[HEATHROW DIRECTOR]

It will be interesting... you can't train a controller to the exacting standards required at Gatwick in a short time. It's a highly skilled job.

[obwan]

Arriving aircraft are not to have crossed the start of the runway until departure is airborne.

I'm glad I've retired:

[chevvron]

It will be interesting... you can't train a controller to the exacting standards required at Gatwick in a short time. It's a highly skilled job.
I agree, it would take a long time to acquire the necessary skill and experience which is needed at Gatwick.

[kcockayne]

HD & Chevvron are, of course, correct. At such a busy station new controllers are going to take time to "find their feet" & to build up the confidence necessary to be able to continue the "slick operation" which currently pertains. It won't happen overnight, so be prepared for some lapses in the present tight spacing & expedition.

[Nimmer]

The Gatwick planned summer movement rate (8 hours of 55 movements), plus the "normal 40 hours" doesn't allow for lapses in spacing!!,

[kcockayne]

Maybe not, but it's not something that you can just step in & do without a lot of training & experience. I'm sure that the experienced mentors will be keeping the new ATCOS on their toes, but I wouldn't expect them to display the same level of operational performance, on their own, straight away.

[Nimmer]

Yep I agree, unfortunately GIP don't always understand that.

[jmmoric]

55 movements per hour? Now even I'm really impressed.... Considering it takes some 40+ seconds to be airbourne from throttling up..

I guess it goes ok with tower separation, though a bit tight, but what is the rate in poor weather then?

[HEATHROW DIRECTOR]

54 an hour!

[Gonzo]

Really? Do we now put flow on when a newly valid ATCO is plugged in? Why are we expecting newly valid KK controllers to struggle with doing 55ph SRO?

Just wondering.

[Musket90]

The 55 runway movements per hour will likely have an average delay factor agreed by all involved and applied by the schedulers. For example at peak times when runway demand is highest, departing aircraft could expect an average delay at the holding point of say 10 or 15 minutes. Same may apply for arrivals depending on where the demand is. It's physically not possible to sustain 55 scheduled movements per hour on a mixed mode runway for several consecutive hours. There has to be a "firebreak" after these peak hours where the scheduled number per hour is reduced so any delays built up during the 55/hour peak can be dissipated. This is common practice in airport scheduling.

Last summer Gatwick scheduled 55/hour for 3 hours of the day only with two consecutive hours at 55 movements but the two consecutive were late afternoon period when there are very few "heavy" aircraft types involved which therefore does not require increased vortex spacing and minimises runway occupancy times which helps towards achieving the 55 movements without much delay, subject to good weather of course. I'd be surprised if the scheduled declared runway capacity for summer 2016 was increased as doing so may increase any delays that last summer's declared capacity schedule created.

[kcockayne]

Gonzo
I do not expect newly validated controllers "to struggle". I'm sure that they will do very well, & improve as they go along (& soon be as good as the experienced 'KK ATCOS). But, it's only natural to "feel your way" for a while as you build up your performance & confidence. Gatwick is a demanding job & requires peak performance to ensure that the standards are maintained - especially from newly validated ATCOS. Some will be "better" than others (especially those with similar experience elsewhere) of course, but the nature of the task at Gatwick is such that I would expect new recruits to have to work their way into it; wouldn't you ?

[terrain safe]

kcockayne

No. They must be able to deal with everything that standard traffic throws at them including the volume that Gatwick generates. Their watch members will keep half an eye on them especially if something unusual happens and will always offer some advice, and indeed take some back as well as new people often have a different way of doing stuff. But feeling their way in? No, that's what the training does.

[Lissart]

"especially those with similar experience elsewhere" Some of the profiles of new hires might surprise. The phrase in quotes just does not apply. Therefore longer learning curve.......

[ATCO3]

I'd be surprised if the scheduled declared runway capacity for summer 2016 was increased as doing so may increase any delays that last summer's declared capacity schedule created.

You obviously haven't seen this then? http://www.acl-uk.org/UserFiles/File/Gatwick%20Summer%202016%20Capacity%20Appendices%20Updated%20 02Nov15.pdf

There are literally no firebreaks in the schedule anymore and this may be a big issue this summer when trying to balance demand!

As for the new controllers they will be trained to the same high standard that was expected of NATS controllers because essentially they are trained by NATS controllers.

But they will have to hit the ground running if they validate during the summer.

For what it's worth it will be a challenge for everyone at Gatwick this summer. :eek:

[The Many Tentacles]

If they're scheduling 55 per hour for more than twice as long every day then the summer is going to suck for the AC sectors as well as TC.

I'm assuming it's been pointed out you can't fit 2lbs of s**t into a 1lb bag

[EastofKoksy]

I doubt there are many controllers around with experience of high intensity single runway operations similar to Gatwick. As with any newly qualified person they will need some consolidation time.

GIP can live in fantasy land with their computer models and schedule as many movements as they like. It remains to be seen if this is achievable! Hopefully this summer the TC South sectors will not end up as a capacity buffer/shock absorber for over ambitious airport scheduling.

[Nimmer]

GIP do live in a fantasy land. There has been talk of 70 an hour using TBS!!! I kid you not.

If the slots are all filled, with minimum staff at TC, LAMP airspace, a few newly valid tower controllers, the summer could be fairly "tasty".

[EastofKoksy]

Lol!! How many A380s are included in the 70?

[T250]

GIP do live in a fantasy land. There has been talk of 70 an hour using TBS!!! I kid you not.

If the slots are all filled, with minimum staff at TC, LAMP airspace, a few newly valid tower controllers, the summer could be fairly "tasty".

More encouragement comes from the fact that GAL/GIP recently threw out some senior management at the end of last year. They were replaced by individuals with zero aviation experience or knowledge. One of whom used to run a chocolate factory.

Seems Willy Wonka/W***er is going to be running the show this summer, plus all his umpa lumpas :hmm::}:E

[Not Long Now]

As EOK mentions, the type mix may well be the limiting factor. Unless they kick out the Emirates 380, or the older 75s and the like which aren't RNAV compliant, or pray for permanent lovely weather, even 55 won't work...
Still, I'm sure 'the powers that be' have it all in hand.:ugh::ugh:

[ATCO3]

GAL/GIP just don't get the difference between a model and the real world. They always look at what new things they can do before fixing the current issues.

They simulate higher runway capacity and think by using TBS and any other 'new' technology it can be achieved in the real operation. What they don't get is that we already do TBS at Gatwick it's what the controllers in the tower and for that matter at TC are paid to do.

Tower use their experience and judgement to pick a gap size based on weather conditions and any limiting factors such as WIP then we ask our colleagues at TC to make it happen.

Most of the time everyone is really good at this but there are too many variables that affect the outcome. To list just a few:

Controller variability - all controllers are different and can be different from day to day which can effect how tight you can safely push it.

Aircrew and aircraft variability - similar to above and especially having heard rumours of the amount of low hours crew the major carrier at Gatwick has! Also different operators can fly similar aircraft quite differently which makes it harder for radar.

Weather variability - the best weather for high runway ops is a steady moderate wind down the runway with good vis throughout the day.

The list could go on but we would be here all year. The bottom line is Gatwick needs to run like a well oiled machine from start to finish to make the level of traffic we had last year work let alone this year and all to often it doesn't!

There are so many things that Gatwick (all the airport stakeholders) need to improve to make the current operation sustainable before we even consider any more than 55 an hour!

[zonoma]

I wonder what buffer has been built in to the recruitment or are they naively thinking that every recruit will validate, that is more of an issue. What happens if none of them make it?

You cannot have a "bedding in" period either, once they are valid they should be able to cope with any level of traffic, that is why training takes so long where ever you are stationed.

[kcockayne]

I disagree. It is my experience that pretty much every ATCO gets better with practice. That does NOT mean that they are performing badly, or unacceptably, for a few months, or whatever, after validation ; which is the required standard for them. Just that after qualification practice makes perfect !

[HEATHROW DIRECTOR]

Agreed. The examiner who passed me for my driving licence said: "Now you learn how to drive..."

[tubby linton]

Out of interest, would anybody like to guesstimate what will the average airborne holding delay be into Gatwick this summer? Will we see speed reductions over France to regulate the flow?
I must practice saying "Minimum fuel" I fear.

[Not Long Now]

Presuming it's busier than last summer I'd say about 20 minutes for the last rotations returning at 22.30ish.

[tubby linton]

Early afternoon on the weekends seemed to be good for twenty minutes last summer.

[Nimmer]

Calling Minimum fuel actually ,actually makes no difference to ATC whatsoever.

You may be asked how long you can hold for, given an update of the estimated delay and whether you wish to declare an emergency.

Other than that you will continue in the hold with no priority until a fuel emergency is declared.

Harsh but true.

[30W]

Indeed I expect nothing other than a testing Summer 16' ar KK, for all parties!

A few observations from a nowadays KK pilot - not necessarily correct ones, but intended to widen debate:-

1. Should airport scheduling allow for ATCO's U/T? In my opinion not - how can you schedule when a U/T is plugged in or isn't? I also expect a few opportunities to be missed- the very slick KK operation comes from experience and competence, but you have to be allowed to gain it in a safe supervised manner, which is what happens. Missed opportunities, points of view, alternative methods are hopefully for debrief?

2. Can flow rates be set because a newly validated ATCO is in position - surely not - many slots effect departures many hours down route and the rate can't be accurate as to who 'may' be in position or not that many hours away from the point in question.

3. KK was testing for all last Summer, this year, as expected, it will be even more so.... A few ideas follow:-

4. Greater co-ordination on gapping: there at times seems a bit of an issue on delays, airport taking knock on departure delays and NATS on holding delays. Changes in gapping to help clear departure backlog clearly have an impact on airborne delays. This combined with other factors DID result in at least a few/several enroute S17 overloads last summer. Should these controllers be subjected to this stress without exploring more intelligent ways to mitigate it?

5. Late TWR changes to gapping to allow more departures seems to impact the above ( not deliberately so I know), pushing a problem 'upstream' without conscious knowledge of the effect.

6. AMAN struggles to cope with the above, and EATS at KK sometimes appear to struggle at times to be realistic to the AMAN initial prediction. More manual oversight/control of AMAN for KK??

7. Several times last Summer was slowed to minimum speed at FIR entry by en-route due 15-20 minute delay expected at KK. On transfer to TC told no delay (yes, appreciate officially that means not greater than 20'). On query told no idea where 'next door' got that from and indeed on arrival not more than once round the hold, on several occasions 'straight off' without even a 'spin'.....
Now en-route have done what is right and good management under the information available to them (AMAN?), but that information has proved to be totally inaccurate....

Extend XMAN to include KK? But for this AMAN timings need to be accurate and reliable!

As an extra, is there now a need this Summer to formally put a formal rate on KK arr for the protection of the system and ATCO's?

8. Speed control - poor conformance by some pilots/operators led to go-arounds. This area has to improve! I observe decisions being made sometimes by crew to 'protect' themselves from go-around by 'reducing' early so to ensure the runway is clear when they get there. The impact on the stream selfishly doesn't concern them at the time:ugh: I would suggest that mode 'S' is monitored in a more controlled fashion, and the offender is sent around regardless rather than an impact on either the next departure or arrival? Harsh perhaps, but perhaps the only way such offenders will learn?

9. Greater understanding/forewarning for pilots of A380 operation (yes I've been here before - sorry!). Late reversion to RNAV ops still occur at KK when it seems far better warning could have been given. Can't a better 'heads up' of sequencing be given to TC TIMBA/WILLO so aircraft can be forewarned in advance of only finding out with KK INT?

10. Use of 'Super' by EK and ATC alike would help crew situational awareness and warning of impending RNAV likelihood.

11. Interestingly followed an EK into CC this week one evening - vectored and cleared for the ILS behind. Now I'm not CC based and presumed (silly I know!) that it was a 'triple' as 'super' not used by either party and not told to expect of, or fly the VOR/DME app. Only heads up was when been transferred to TWR to "expect LOC deviations as I was 7miles behind an A380...."

12. Re above - different standards? This wouldn't have been allowed at KK, I would have been informed and flown an RNAV. Why are there different procedures for CC/KK? Surely the risk associated to aircraft following A380 with respect to ILS signals is the same at both? These UK standards/differences re A380 ops are still not published in the AIP or MATS Pt1 so we can all be aware/understand them.

Please take the above as its's meant - a widening of discussion, learning for myself etc. KK, TC et al all do a great job!

There is no doubt however KK last year was an eye opener for many, this year will only be worse given more movements taken on. We all need to evolve, and to perhaps take a slightly different systematic approach going forward (pilots and controllers alike).....

30W

[tubby linton]

I recently had a visit to Nats and sat on the Gatwick Director position.. The atco I talked to was quite surprised that converting us at a late stage to an Rnav caused us a lot of button pushing and rebriefing.
This was reinforced when another atco plugged herself in and asked an aircraft if they would do an SRA for her currency. You could hear the big think bubble coming from the aircraft!
30W I totally agree with your point 7. I sometimes wonder if the two entities are actually talking to each other.

[Talkdownman]

asked an aircraft if they would do an SRA for her currency. You could hear the big think bubble coming from the aircraft!
I have had aircrew state that they are not equipped for an SRA...

[EastofKoksy]

tubby,

Being told to slow down then finding out there is no delay or that you can maintain high speed then be told to hold is obviously an internal comms problem in ATC for which there is no excuse. Unfortunately this is not something new!

As for controller appreciation of pilot workload caused by last minute changes. It is still possible but more difficult than it used to be for NATS controllers to do familiarisation flights. These have always been voluntary. NATS managers did not help the situation by regarding them as 'jollies' and insisting controllers do them in their own time.

[30W]

Tubby,

Following an earlier thread glad you took time to visit!

My point in '7' really is not so much about internal voice co-ordination, but more the electronic data supplied. AC are doing their jobs entirely intelligently slowing inbound traffic when the AMAN EAT data is showing delays ahead. The query really is the accuracy of this data as several times it has totally contradicted the actual situation/status.

What is your experience of point '8'? I feel some some pilots ar NOT following the speed control accurately or in completeness. We have a responsibility to ATC and the system on the whole here and some colleagues are letting us all down. Even is a go-around is avoided it can mean a lost departure if a 'gap' reduces due to poor crew speed compliance. This is something we owe controllers at KK as they are trying to sustain a huge runway rate which ultimately both airport and operators want.

I have had aircrew state that they are not equipped for an SRA...

That one makes me laugh! Really though, there are many pilots who have never experienced an SRA for real..... I mean unlike many years ago, they really are an extremely rare event and in most cases never required as there is a contingency approach available should the ILS not be available, and a better option than a modern day SRA (they're not like the old half milers of years back).

Totally agree with EOK's point on Famil's - often equally difficult to organise at our end, red tape and authorisation levels have made sorting very difficult! Doesn't stop me completely doing so, it feels like a 'fight' every time however :-(

My initial post isn't meant to be a criticism, but purely an open debate of how we can improve things for all in steadily increasing traffic volume.

[tubby linton]

30W I have not actually come across poor speed control by other operators but on my visit the atco had aircraft speed displayed to him to regulate his flow . If aircraft are not complying then it should be highlighted to them, and regular offenders should be contacted.
Sharklet equipped airbuses decellerate at a slower rate than a classic ,and their numbers are increasing rapidly.Trying to slowdown , descend and achieve a cda can be a challenge in one.

[EpsilonVaz]

As an LGW based pilot, can I ask what is the advantage of 160 to 4 over 170 to 5?


I think you'd get much better speed conformance using 170. Folk would actually do 170 to 5, instead of 160 to 4 actually being 160 to 5 most of the time.


It's just the time it actually takes to configure after 4 miles doesn't leave a lot of room.


I'm on the A320 but I'm sure the story is similar for the 737.

[30W]

The main issue for the B738 is that at normal weights 160kt does not allow a low drag approach as require a gear down/F15 configuration to comply. This isn't economic (requires thrust against that drag level), increases noise under the flight path, increases CO2 emission etc etc.

170 for us works well to keep idle/minimum thrust till 5nm.

All types are different, and that's the poor lottery both the system and ATC try to accommodate. For what it's worth, KK are EXCELLENT in accommodating either speed as long as suitable notice is given to KK INT.

TL, yes aware that 'S' is available. It's also true that very occasionally a dep is missed due to poor speed control compliance reducing the arr gap. The traffic is with TWR at this point rather than DIR, so have executive control. With 55/hr we can't afford any missed rwy time, and that rather than miss say a dep movement because of the above, the offender on speed control is sent around by AIR. I know it doesn't stop a movement loss at that point, but it does get the message across and enforce compliance which in turn will help the rate in the medium term....

[t-bag]

Calling Minimum fuel actually ,actually makes no difference to ATC whatsoever.


Out of interest do our ATCO friends know what it means to us as pilots?

[Del Prado]

Really interesting points raised in the last couple of posts.

A380 and RNAV. If you get offered an RNAV too late then turn it down and you'll get an extra 2/3 minutes 'delay' for an ILS (usually extended vectoring rather than round the hold). The spacing behind an A380 is 15/20 miles. This may be reduced through RNAV approaches but if you don't feel you have enough time to set up for it then take the delay.
It can be very difficult to know the order more than 40 miles from touchdown in light traffic conditions purely because of the order they are transfered from SW or SE sectors and also how good a job they've done of getting down.
During periods of holding the landing order is fixed much further out and is much easier to stick to so there should be plenty of time to set up for an RNAV then.

AMAN. Historically spacing requirements have been coordinated by the tower as an 'immediate' request. With the advent of AMAN for Gatwick there does seem more of a need for tower to communicate the predicted time of any changes to the spacing regime for the next 60/90 minutes.
As use of AMAN at Gatwick matures I see no reason why that couldn't be incorporated into the operation.

Speed Control speed conformance by A319/320's is pretty awful at Gatwick. 160 to 4 often becomes 160 to 7. (and don't start me on traffic that slows below 180kts as soon as they're established!)
As has been pointed out this risks go arounds and missed departure gaps leading to extra delays but also if the ATCOs have no confidence that the aircraft will maintain speed then 3 mile gaps become 4 and 6s become 6.5s. We do understand the difficulty of being stable in a A319/A320 while doing 160 to 4 but some airlines do it better than others and I'm sure if GIP/GAL got together with a couple of the worst offenders then delays would reduce markedly at peak times. (On the other hand, if inbound and outbound demand is low why can't 160 to 6 be accommodated?)

[The Many Tentacles]

Out of interest do our ATCO friends know what it means to us as pilots?

As far as I'm aware, it means you have enough fuel to make an approach and then divert to your alternate to land there. Whether or not you have enough to hold there I don't know. We did have something about on our briefing system a while back, but the exact details escape me now.

You need to declare a PAN before you get any preferential handling from ATC though, but I guess you already know that :)

[Not Long Now]

So manytentacles answers the question on minimum fuel...
Yes, in theory, ATCOs DO know what minimum fuel is, but obviously in practice, some do not. I THINK the majority probably do, or at least will soon find someone on hand who does. Doubtless we'll find out how many pilots know it too this summer...

[30W]

Hi DP!

Thanks for responding...

A380/RNAV

Understood, but why can I go to CC and end up 7nm (vortex minima) for me behind a 380, on an ILS app, with only mention being that I can expect some LOC fluctuations as I'm released to TWR when KK rules seem entirely different? Is it to do with taxiway proximity or different approved safety standards between Pt 2's?

Earliest possible warning of the RNAV most appreciated as and when it can be provided :ok: In the Summer, when holding is now the 'norm' whilst we are in the hold is ideal..... Even more so situational awareness wise from the WILLO side when EK hasn't been on the same freq prior to KK. The departing 380 is even more difficult for us because early awareness just isn't possible as it's not on freq with us at all.

AMAN

AMAN is very accurate for LL. We DO in my opinion need to 'mature' it's use for KK because as I've alluded to, AC are using its data to make sensible executive decisions to aid us the pilots and the TMA. Sometimes, and I'm not suggesting this is the majority of times, because that wouldn't be fair, but occasionally the AMAN data is rather inaccurate. This leads to lack of confidence in it on our side and a wonder if the 'system' is in fact joined up, which is an unfair impression...

Speed Control

Im glad it's not only myself who believes there IS an issue here...was starting to feel rather lonely!

Question is - how do we resolve it? What internally do watch colleagues believe is the approach/answer? One things for sure, if we collectively are going to move 55/hr, or close to, then we must address this issue. I appreciate I may have suggested a rather 'sledgehammer' approach, but the fact that the culprit gets 'away with it' only breeds further, and more widespread non-compliance....

Cheers
30W

[30W]

As far as I'm aware, it means you have enough fuel to make an approach and then divert to your alternate to land.

Minimum fuel - The term used to describe a situation in which an aircraft’s fuel supply has reached a state where the flight is committed to land at a specific aerodrome and no additional delay can be accepted. (PANS-ATM, DOC 4444)

Simply put we are now committing to the destination as we calculate we can land there with 30' of fuel remaining (final reserve fuel). Again, following the declaration of 'minimum fuel' we are effectively 'advising' you we have NO fuel alternate now available to us, we are committed to land at destination.


In circumstances where an aircraft has declared minimum fuel or is experiencing an emergency or has declared minimum fuel, or in any other situation wherein the safety of the aircraft is not assured, the type of emergency and/or the circumstances experienced by the aircraft shall be reported by the transferring unit to the accepting unit and any other ATS unit that may be concerned with the flight and to the associated rescue coordination centres, if necessary. (PANS-ATM, DOC 4444)

So, does DIR inform the TWR of a 'minimum fuel' declaration so that hopefully avoiding a go-around is definitely assured?

As a pilot I fully understand and accept that no priority is given until 'minimum fuel' is raised to a higher status. It is however now an ICAO requirement that we declare it. It does infer to me however that ATC MUST advise us of ANY change to already communicated delay/track mileage. This then allows raising of the 'minimum fuel' status to a Pan or Mayday if we consider it necessary.

Cans and worms are springing to mind.....:eek:

[Blueeyedviewer]

The reason for the issues around the A380 is the distance the ILS is from the Tarmac at KK. At CC and other places it's further away so the aircraft doesn't enter the critical area. The deflection it causes as it turns off is very apparent with one behind, even at 12 miles sometimes. That's why there is such a large buffer spacing wise

I can't speak for arrivals but from a departures perspective the gap is planned once the 380 has pushed and in line with its estimated take off time given by CDM. This then allows radar to arrange as best as possible the sequence / RNAV etc...to coincide with the time coordinated by TWR

It's not a perfect system..

[Not Long Now]

Quite, so here's a hypothetical...
unexpected delays for some reason, let's say a burst tyre. Middle of the day, nice weather, nobody expecting much holding. First pilot chimes up minimum fuel, 'roger, delay 10 minutes' says ATCO, no priority given or expected by director or by tower in doing best to ensure no go-around. Another pilots adds minimum fuel, still no priority to either. Perhaps another... At what stage, if at all, do we have to decide that these are all committed, and that should anything untoward occur, perhaps with a departure, there may now be 3 or maybe more immediate MAYDAYs with perhaps little prospect of reaching an alternate. Are departures stopped, queues jumped, or still carry on and hope nobody ahead stays on the runway for any reason...
If, as a pilot, you hear a couple of minimum fuels declared and you are getting that way too, do you decide diversion now would be a better option? Imponderables????

[nodelay]

Can someone explain to me how Gatwock achieves such a high runway rate per hour on one runway? Is it a one in one out system with standardized arrival gap spacing? I'm doing some research and any assistance and or advice on similar single runway airports would be warmly welcomed.
Regards

Do you work for ANS?? 😜

[zonoma]

I'm going to do my best to answer as much as possible from an AC perspective:

1. Should airport scheduling allow for ATCO's U/T?
I agree with you, once an ATCO is valid they should be able to handle the busiest of situations and then respond appropriately to an emergency too. Someone cannot validate and then have a "bedding in" period, what happens if they are superb to 90% and cannot do 100%? However person-management should be carefully monitored by the supervisor to ensure they have the correct personnel in situ for certain periods - we've done it for LAMP too. Two fresh faces during their first busy spell should be avoided where possible, and closely monitored where not.

2. Answered above.

4. Greater co-ordination on gapping: This combined with other factors DID result in at least a few/several enroute S17 overloads last summer.
The only bit of this I can answer and yes it did, and the airspace has now changed so this summer will be "new" for both AC and TC. There have already been a couple of situations where this issue is being addressed so hopefully by the "peak months" we'll be better placed to deal with them better.

5. Not my remit.

6. AMAN struggles to cope with the above, and EATS at KK sometimes appear to struggle at times to be realistic to the AMAN initial prediction. More manual oversight/control of AMAN for KK??
Manning, I'll let you decide where that answer lies.

7. Several times last Summer was slowed to minimum speed at FIR entry by en-route due 15-20 minute delay expected at KK. On transfer to TC told no delay (yes, appreciate officially that means not greater than 20'). On query told no idea where 'next door' got that from and indeed on arrival not more than once round the hold, on several occasions 'straight off' without even a 'spin'.....
Now en-route have done what is right and good management under the information available to them (AMAN?), but that information has proved to be totally inaccurate....

Extend XMAN to include KK? But for this AMAN timings need to be accurate and reliable!

As an extra, is there now a need this Summer to formally put a formal rate on KK arr for the protection of the system and ATCO's?
This is part of the problem, again with better foresight of what is coming out so knowing what the arrival spacing is to be will be of help, but as this is forever changing and not that easy to forward plan, the solution is already flawed. XMAN for Gatwick is a long way off at the moment, AMAN can change in a moment where AC either have less than 5 and it's 15+ or visa versa. Coupled with S17 and S22 not getting KK arrivals spaced and often above profile, their job to get you down and slow you down is compromised. Who is going to supply the money to get the system improved?

8. Speed control - poor conformance by some pilots/operators led to go-arounds. This area has to improve! I observe decisions being made sometimes by crew to 'protect' themselves from go-around by 'reducing' early so to ensure the runway is clear when they get there. The impact on the stream selfishly doesn't concern them at the time I would suggest that mode 'S' is monitored in a more controlled fashion, and the offender is sent around regardless rather than an impact on either the next departure or arrival? Harsh perhaps, but perhaps the only way such offenders will learn?
Not just on final approach, however AC this year are getting quite an informative brief regarding speed control, it includes the accuracy of conformance for several aircraft types and will possibly lead to a few "ticking off"s this summer due to non-conformance. I'm not sure if TC get the same brief however the information is now within NATS so I imagine it'll roll out to them at some point if not this year.

9. Not my remit.

10. Use of 'Super' by EK and ATC alike would help crew situational awareness and warning of impending RNAV likelihood.
AC will never use "Super", possibly a little early to start the awareness.

I hope that gives you a little more of an AC perspective. You seem to be very well informed so probably know much of what I've written already. It is going to be a testing summer so please bear with us, and do your best for us and we'll try our best for you. I am guessing you do, it is very frustrating when you get the ones that certainly don't. :}

[30W]

NSLN,

Wondered how long it would take us to get to the doomsday scenario, but your right, it's a perfectly valid question....

At what stage, if at all, do we have to decide that these are all committed

As soon as 'minimum fuel is declared' in my opinion, that is the ICAO definition and the reason we are advising you.....

Are departures stopped

If mutilple aircraft declare minimum fuel, it seems from my side at least, a perfectly reasonable step for the GS to take. More a question for yourselves though,at what point would ATC decide to put a stop on departures?

In your final question, yes personally making a diversion WOULD be now high on my list. In deciding to commit, I should take into account the reasonability of landing at KK. Your scenario gives me high question as to that probability and I should be taking a command decision accordingly.

LL is often used as the fuel alternate, in times of good weather, when LL NOTAMS do not preclude decalring LL as an alternate etc. I would be expecting to declare a Pan on the way I suspect as an undelayed approach at LHR would not occur otherwise.... If not LL then GW normally - same scenario re Pan I suspect as we all know 'Essex' is far from a quiet place these days.

I don't know of colleagues who will be carrying minimum flight plan fuel to KK in summer seasons, that said, the extra added will of course vary..... We rely on experience, statistical data etc in making that decision, but doesn't mean we can't get caught out and end up in that 'minimum fuel' scenario if the tactical position is way off the stats or recent experiences....

We've not ended up in the 'multiple' scenario you suggest, let's hope from both sides of the mic that we never do. It's right that we all think about how we would handle it if we did though!

30W

[30W]

Zonoma,

Thanks for the time spent in such a comprehensive response and addition to the discussion!

I'm just off to bed prior some 'earlies' but will respond better at the end of the week:ok:

If all we're doing here is sharing thoughts, provoking discussion in the flight deck and in the canteen, then that's a good thing hopefully!

30W

[Dan Dare]

We've not ended up in the 'multiple' scenario you suggest, let's hope from both sides of the mic that we never do.

From my side of the mic I've had far too many 'multiple' scenarios, the worst of which have been from un-forecast and therefore un-flowed fog across the whole of the south east. You would not believe how quickly we run out of runways! It doesn't happen every month, but when it does they are memorable! When you've got 3 PANs and a Mayday all requiring a sterile runway and more delay for everybody else it concentrates the mind a bit. I can't imagine it's a barrel of laughs from up there either.

[Del Prado]

7. Several times last Summer was slowed to minimum speed at FIR entry by en-route due 15-20 minute delay expected at KK. On transfer to TC told no delay (yes, appreciate officially that means not greater than 20'). On query told no idea where 'next door' got that from and indeed on arrival not more than once round the hold, on several occasions 'straight off' without even a 'spin'.....

Doesn't that mean its working? ;-)

Ok, this response is slightly tongue in cheek but if delay is 15-20 and you slow down wouldn't you expect your delay to reduce? Maybe not 20 down to 0 but if you're still getting once round the hold or a spin then the early speed reduction was advisable and even when you came 'straight off' I bet there was enough traffic ahead to warrant 220kts or min clean so the speed control did its job to a large degree.

(With apologies for the overtly contrarian post)

[The Many Tentacles]

Minimum fuel - The term used to describe a situation in which an aircraft’s fuel supply has reached a state where the flight is committed to land at a specific aerodrome and no additional delay can be accepted. (PANS-ATM, DOC 4444)

I was close.................ish :)

Thanks for the correction

[30W]

Hi DP,

Appreciate the devils advocate approach :ok:

Yes, you're right, it does make a difference and indeed aid the system overall if applied properly and sensibly. The few minutes longer however and finally receiving straight MAY for 26 prior HOLLY implies that the AMAN data of 15-20 prediction was totally flawed/ incorrect perhaps? In this case a delay occurs through been slowed up when in fact perhaps no delay would ever have occurred anyway... The issue is that of inaccurate AMAN data for KK, leading to loss of confidence and perhaps unnecessary decisions being taken, albeit for exactly the right reason given the data displayed....

I've run some data at work today to demonstrate the positive effect the speed reduction CAN have under the right circumstances. If anyone can educate me how to embed an iPad saved photo into my response text I can share it with you all.....

[tubby linton]

From another thread and posted by PPrune Towers -If you explore USER CP in the yellow bar at the top of the page you'll find you all have an album for uploading shots. Once in they have a url to include in posts.

[30W]

Just exploring speed reduction at the boundary effect:

Image 1 shows actual FMC predictions based on an average decent profile - M0.78/270kt/250kt at SLP/220kt HOLLY. Elapsed time REVTU-HOLLY 19mins

Image 2 shows predictions based on a typically ATC reduced profile with delays - M0.75/220kt all the way to HOLLY. Elapsed time REVTU-HOLLY 23mins.

So, 4 mins, 1 holds worth saved with ATC intervention at the boundary. Definitely shows it's worth it, however, it relies on AMAN data for KK being correct and that's the point being made, at times it most definitely isn't :(

http://www.pprune.org/members/5623-30w-albums-nd-pictures-picture221-image1.jpeg


http://www.pprune.org/members/5623-30w-albums-nd-pictures-picture222-image1.jpeg

[Del Prado]

Thanks for that 30W, very interesting. I do agree with what you say although there is a part of me that thinks if AMAN was developed to be a perfect tool that eliminated all holding, pilots would still turn up at the hold moaning there was no delay when they'd had to slow down! ;-)

A further contrarian view from me, large pinch of salt, etc.

If you're slowed at the boundary and get a spin or join a sequence at standard speeds then in many ways the AMAN speed reduction has done its job.
The runway has been utilised efficiently with a consistent and stable stream of inbounds. Efficient runway utilisation means profitable airport operator and lower charges.

Even if there were gaps in the inbounds, more often than not, these gaps will be used to clear a backlog of departures and when you turnaround there will be fewer outbound delays.

Slowing at the boundary would surely only be a 'failure' for the system if it led to a gap on the approach which couldn't be filled by a departure?

The bigger issue to you as a pilot, of course, is whether you're losing your place in the queue and if you lose faith in the system it will encourage the 'hurry up and wait' mentality of trying to get to the hold first but if everyone is slowed and AMAN order is respected that shouldn't happen.

As I say, just a contrarian view based purely on observation but maybe a different way to think about it as Gatwick gets busier.

[zonoma]

Another point to consider is that even if the AMAN data isn't completely correct, some controllers will be aware of the 'average' delay. If at check-in the average delay is 15-20 minutes, issuing a speed restriction is probable and it is very possible for the delays to reduce completely within the 23 minutes it then takes to reach WILLO (sticking with the scenario 30W posted a couple ago). This would produce the situation being discussed.

[EastofKoksy]

Any worthwhile AMAN should be able to inform controllers what the delay is expected to be for a particular flight. It is no good telling pilots what the delay is right now when they won't arrive at the approach fix for another 25-30 minutes. This goes back to the point in my original post on this topic that a failure of comms in ATC is leading to controllers being given rubbish information about delays that in turn can mislead pilots.

[ZOOKER]

This is a very interesting discussion.
Tubby's post No.43 is surprising. I didn't realise EGKK still did SRAs. During the early 1990s, they were withdrawn at EGCC, (I think), due to the NODE(M) display equipment being unsuitable, according to unit management. And also, having the MCT VOR sited next to the runway, gave us other approach options. The unit remains unable to provide them.
Presumably EGKK/TC are still using the 'BARCO' displays? How many of the TC airfields still do them, and what is the minimum number required to retain currency?