atc-discussion 'Spotlight' Series
-
Similar Content
-
By Harry Sugden
I can only speak from an area perspective, but before the following spiel, it is worth noting that each and every single London controller put in a fantastic amount of effort to the traffic situation they were presented with. Although he was raided beyond belief, @Benjamin Matthews was unfairly put in an unworkable position, but stuck with it. @George Complin implemented a bizarre and totally new way of handling EGLL inbounds at short notice, and thanks to @Matt Weddell for stepping in to provide a bit of relief whilst that took place.
The traffic levels during some of these events are insane and unpredictable; but UK area controllers continue to do an excellent job. This debrief and chasing better cross-border coordination is all aimed at making sure the events are enjoyable - and not just stupidly chaotic!
Summary of Lessons
Pilots do not, it seems, read event posts for routings. Where/if they do, this does not mean the split between published event routes (where multiple are possible) is an even one. As such, ADC supervisors are essential to maximise the departure rate where the arrival field has the capacity to handle the traffic. In the same spirit, it is possible that pilots file routes which appear to be the event ones. For events with traffic levels such as this one - which we were expecting - strict adherence to agreed event routes must be coordinated cross-border. It is difficult to find space to fairly hold inbounds with an RFL240- when enroute holding at LOGAN. Where this is anticipated to occur, it would be sensible to either stop or severely regulate flights from nearer airfields. Planning and implementing stack swap STARs is not a simple task. They work where the sending and receiving sectors have the R/T capacity to implement them, but communicating the change with pilots and executing the non-standard positioning adds to workload. Thus, planning and implementing effective route splits is essential. Clacton is always raided when LOGAN is involved in a Heathrow-Europe City Pair. Continue to plan for said Clacton raid. Revised holding phraseology works. This should be used again.
Traffic Levels
[Departure statistics will be added as soon as they are available.]
Time (Zulu)
Departure Rate (per hour)
Arrival Rate (per hour)
1800-1900
9
1900-2000
19
2000-2100
34
2100-2200
39
2200-2300
32
2300-0000
23
TOTAL
TBC 156
Mean arrival rate from 1900-0000Z - 29.4
Peak inbound delay - in excess of one hour
Peak outbound delay - less than 10 minutes
Eastbound (EGLL Departures)
The departure flow was extremely well managed throughout. Any delays were not significant and the event picture from a departure perspective was one of great success. That is not to say, however, that this was an easy win.
The majority of aircraft filed via DET, as a consequence of SimBrief suggesting (by default) the route that the previous aircraft on the same route planned. As such, a significant quantity of aircraft were re-routed via BPK onto the other of the two published event routes. This was no small undertaking.
An MDI of 3 minutes on all eastbound SIDs was placed on Gatwick - eastbound departures tend to make up the majority of departing Gatwick traffic on VATSIM. This was put in place in favour of a reduced departure separation of 2 minutes (as opposed to the usual 3) for DET departures from Heathrow. This arrangement worked well, however by the time the BIG hold became full the TC SE sector reached capacity. In this case, having a TC coordinator throughout the whole event would’ve helped to have recognised the high sector loading and increase the MDIs for aircraft via DET (from both Heathrow and Gatwick) later on. In this particular event, splitting TC SE would not have made a difference to the complexity/workload, even if we had the ability to do so.
The stream via BPK continued steadily throughout the event, not only to EDDF but to other European airfields. At times, this meant a Sector 12 (combined with TC REDFA) was a viable option. Thanks to short-notice availability, we were able to open a TC REDFA, which then further expanded its coverage into Sector 12 airspace. The focus of area rostering for this event was on the optimum sectorisation for the LOGAN stream (discussed later), and rightly so, but monitoring of the workload that handling departures in addition to inbounds is required.
Westbound (EGLL Inbounds)
Sectorisation, Frequency Congestion & Coordination
We were able to roster enough sectors for the traffic scenario, though not enough to have a coordinator throughout the event - which on reflection, was required.
Frequency loading was fine in most places, except for some particular, significant problems:
Sector 13 (Clacton South, high level) was far above capacity; the TC SABER split opened too late; TC SE was particularly busy as a result of the use of the TANET 1Z stack swap, ALESO 1H inbounds and DET departures all combining together - when this happened, there was no assigned area coordinator. The first of these problems was not acceptable for a VATSIM event. The controller did not enjoy the session, was presented with unworkable traffic (see below), and did the absolute best they could with the traffic levels they were faced with. Without a coordinator in the middle of the event, the situation in the Sector 13 -> SABER -> TC NE sequence would have been far worse.
Generally, when the traffic was where it should have been, coordination was fine. Calling on aircraft from enroute holds was well managed in general, but anticipation of levels becoming free is sometimes a dangerous game. Having aircraft high at BRASO/LAM can cause problems for other traffic overhead inbound to the Midlands, Wessex or Severn groups and so should be avoided.
Coordination with EBBU was virtually impossible due to their high sector loading, meaning the problems caused by aircraft routing via SUMUM had to be resolved internally.
Routes, Spacing & Holding
The LAM stack became full very quickly just around the middle of the event. This quickly rippled back to BRASO, and eventually LOGAN. The spacing into Sector 13 via ABNED/SASKI (though ABNED in particular) was unworkable and insufficient. It had not been the intention to have aircraft routing via SASKI at all, but due to a mixture of both SimBrief defaulting to the previous aircraft’s planned route and a lack of enforcement of event routings by EDDF until the problem had been spotted, around 80% of traffic in the initial wave from EDDF routed via LOGAN.
The two event routes westbound were:
OBOKA Z29 TORNU DCT BREDA DCT ABNED L980 LOGAN (turquoise arrow in the image below) SOBRA Y180 DIK UN857 RENSA DCT ABNUR UT10 ALESO (purple arrow) However, a third - extremely popular - route emerged:
3. SOBRA Y180 BITBU Y181 DEMUL DCT DENUT L608 LOGAN (red arrow)
Until an issue was identified, Frankfurt were departing aircraft on routes 1 and 3 with minimum spacing with the assumption that they were the event routes. This meant that by the time this traffic was handed to Sector 13 (Clacton) by both Amsterdam and Brussels, it was being transferred at a rate of at least 1 aircraft per minute. ‘Bunching’ had also occurred en route such that aircraft were in fact being transferred with less than 5 miles spacing at times, even if they were level separated.
As an emergency contingency plan, the Sector 12+14 controller took all the aircraft via SASKI and vectored them west before re-routing via the TANET 1Z stack swap STAR to BIG (light green arrow in the image). This allowed the Sector 13 controller to focus on presenting something of a workable stream to TC NE (and eventually TC SABER). This arrangement continued until the ALESO 1H arrivals picked up in number.
Coverage from Reims ACC was requested and provided, but was insufficiently used until at least 2100Z, 3 hours into the event. 20 planes per hour were agreed as an absolute maximum on each of routes 1 and 2, but route 3 being SOBRA (and thus appearing to be ‘southbound’ to Frankfurt controllers) meant that numbers far in excess of 20 per hour were launched via LOGAN. Brussels was overworked handling a heavy eastbound stream as well as traffic via SOBRA-SASKI, so it was not possible to re-route airborne aircraft before reaching the Clacton sectors. Amsterdam was overworked with non-event LTMA inbounds as well as ABNED-LOGAN event inbounds, such that the presentation was inadequate at times. (This was to be expected though, given how busy Amsterdam and the ABNED route were). Sector complexity was further compounded by:
Some pilots (particularly those using FS2020 default aircraft) being unable to hold and requiring vectors, or else just holding in very large and disruptive patterns. The use of stack swap STARs being difficult to arrange with pilots without using up valuable R/T time. Additionally, without a coordinator, stack swap STARs may be inappropriately used when sector loading is already high in the destination stack.
However, there was only one significant ‘wrong way holder’. The use of trial phraseology to emphasise the need to check both the charts and the hold direction inputted to the flight management computer was extremely successful, and should be encouraged in future:
“hold at LAM as published, left hand turns”
The situation was not all dire though - landing 39 aircraft at peak is no small feat for VATSIM-trained controllers. The traffic levels required landing this number from 2000-2300Z, however - many of the 23 aircraft who landed between 2300-0000Z were delayed significantly at Frankfurt as they were re-routed and/or restricted by a stop on further departures. Enhanced training for INT/FIN controllers during events could be very useful to arrange to widen the pool of ‘raid-capable’ APP controllers.
-
By Harry Sugden
Heathrow-Frankfurt City Pair - 16th January 1800-2200Z (1730-2230Z) - Area Brief
Roster
The time has come to shine; thank you to all those who've put their name down for tonight's event. Let's get some more feedback telling us how professional our service is! 😉 You do not need to read all of this brief - please read 'Traffic Plan', the relevant sections under 'Sectorisation' according to what you've been rostered on, and the 'Holding' section at the bottom (important! cos trial phraseology).
I'll be coordinating 1845-2045Z - shout at me if you're having any troubles! Also, if a C1+ comes along offering their time to control, send them to me!
Traffic Plan
The official event times are 1800-2200Z. We have two routes published in each direction: outbounds via BPK-REDFA or DET-KOK; inbounds via LOGAN or ALESO. Adjacent ATC has been sourced for both routes.
Departures are expected in high numbers. The event will be mainly departure focused until 1900Z because it takes just under an hour from Frankfurt to the London AoR boundary in the other direction. Expect Heathrow to chuck them out. There will then be a mixed raid from 1900-2030Z ish - Frankfurt have asked us to be ready to slow the departure rate down by halfway through if they get rammed. But in this central core of the event outbounds and inbounds will both likely be in high quantity. From 2030Z comes the arrivals raid, later becoming a holding raid... hold on tight!
We have asked Frankfurt for no more than 20 per hour on each route. This will require Heathrow to land 40 an hour + non-event - more than enough for VATSIM! If the demand on the ground at Frankfurt is greater than this, we may have to be more generous between 2000-2100Z and fill up the enroute holds, otherwise the event could go on all night.
Sectorisation
At peak, we plan to have open: Worthing, Dover and TC SE; Daventry, 2x Clacton, TC SABER and TC NE. (8 sectors)
There are no non-standard splits within the South LAG. The Central LAG, however, has 2 non-standard splits.
AC Clacton - @George Complin @Fergus Walsh @Benjamin Matthews
We have not yet decided how to split Clacton. It will be one of two options: (1) Sector 12 and Sector 13+14, or (2) Sector 12+14 and Sector 13. The former will effectively be an inbound/outbound split, the latter would mean that the controller handling most of the Heathrow inbounds does not also have to speak to any Essex/Gatwick traffic from the east. Please make sure you are comfortable with both split options. The key points are:
Any traffic RFL295- will be with the Sector 14 controller, including flights from EHAM/EBBR. This traffic must be descended to FL240 in good time to avoid Sector 13 airspace, if these sectors are split. They are then presented to TC SABER at FL240, level by LOGAN. Assuming speed control is being applied to high level inbounds above, try to gauge/coordinate a sensible speed and fit them in the stream. Do not delay handoff to TC SABER so they can integrate the low and high level. Traffic via BARMI is 'skipped' by Sector 12 and transferred to either Sector 13 (EGLL FL300 lvl BARMI) or Sector 14 (EGKK FL260 lvl BARMI) by AC North. These inbounds are not released for turn or descent within Sector 12's airspace without coordination (like EGKK KIDLIs in TC NW). EGKK inbounds must also not penetrate Sector 13's airspace (FL245+) without coordination, so coordination with either Sector 12 or 13 is required at some point (if 13 and 14 are split). EGKK inbounds need to be descended quickly to stay on profile for FL140 by ABTUM - this is essential today, because TC SE is going to be very busy and will not want to hear "this aircraft is high at ABTUM, is that OK?". They might say yes, but it won't be. The agreement is FL220 lvl ODROB/BLIXY/SUNUP - please look at where these are on the display before you start controlling and make a real effort to (a) descend in good time, and (b) transfer to TC SABER in good time. The Sector 12 controller will also be covering the northern portion of TC East (known as TC REDFA), as we plan to only split TC SABER off. There is an agreed levels diagram for TC REDFA on this post which is worth having a look at for any intra-TC East agreements.
TC East - @Oliver Rhodes @Nathaniel Leff
We plan to open TC SABER from 2000Z, when the bulk of the inbound traffic will start to come through. Your job is relatively simple: transfer the planes to TC NE in trail and at reasonable speeds (290/300 kts is not reasonable if there is holding at LAM!). We may start holding at BRASO - well, inevitably we will - and this is your job to manage. TC NE should then call aircraft on to LAM; but feel free to give them a nudge if you see spare levels. We do not plan to stack swap via TANET for this event, as there will be inbounds from the south. Thus, if BRASO starts to get full this is a warning sign that LOGAN is next and there are too many planes. Let me (as coordinator) or the Sector 13 controller know so they can start the chain of "SLOW DOWN!".
EGKK inbounds need to be descended promptly to stay on profile for FL140 by ABTUM - this is essential today, because TC SE is going to be very busy and will not want to hear "this aircraft is high at ABTUM, is that OK?". Give Sector 14 a wee nudge if you aren't getting them level by ODROB/BLIXY/SUNUP.
There is an agreed levels diagram for TC SABER on the above Temporary Instruction post. Whoever is covering Sector 12 will also be covering TC REDFA, as the remaining part of TC East.
TC North East - @Fergus Walsh @James Yuen @Sebastian Rekdal
Please facilitate Heathrow not holding for as long as possible; late, fast planes to APP are a pain in the backside. Offer full(er) releases towards the start of the event if you can. No planes to Heathrow 10 miles from LAM at 270 kts! Be proactive with calling on aircraft from BRASO if/when we begin holding there. Otherwise, NE is relatively easy.
TC South East - @James Yuen @Jack Edwards @Loui Ringer @Benjamin Matthews
I'm sorry in advance if your sector gets a battering, but you have every right to tell Gatwick to slow the rate of departures down with an MDI (don't you dare touch Heathrow though 😛) and please shout at me if at any point it's getting too much. The essential tips for this sector:
Get all of those DET deps on a heading from EPM as the BIG westerly track is going to be busy tonight, so let's avoid any loss of seps! You have two options for these departures when the BIG hold is very full: (1) take them towards Gatwick and south of the BIG hold, giving climb earlier, or (2) the less preferable option to vector them underneath the BIG stack and climb later. Be very careful that EGLL DET departures do not enter Area 6 of the Gatwick RMA at or below 6000ft. They must be MSL or higher by the Gatwick extended centreline. Do not delay the transfer of departures via DVR to AC Dover. I know this may seem like a relatively simple comment to make, but it's very easy during events to let these aircraft level off at FL180, which can be detrimental down the line. If Dover gets them too late, they may not reach FL245+ by KONAN, causing issues if Brussels/Maastricht are split. Dover also needs to arrange nicely before transfer to Maastricht. Tell Dover early if BIG is filling up. They will eventually start holding at TIGER and will also tell Reims to start slowing planes significantly if we are holding at TIGER. Gatwick LAM departures get a lot more complicated with a full BIG stack, but the FL130 by the TC N/S boundary rule becomes even more essential during a busy LTMA. You must coordinate with TC NE if you screw up - it's usually absolutely fine if coordinated well, but not coordinating just doesn't help anyone. In previous events, planes have made it abeam BPK without being transferred from TC SE - this should be avoided!!! AC Dover - @Nathaniel Leff @Nick Marinov @Ben Wright
You will likely be another busy controller tonight, and we don't have any options for splitting Dover at this time - sorry! If you anticipate a really busy period with LL DET outbounds and LL inbounds (likely from 1900Z onwards), then feel free to impose an MDI on Gatwick deps, via TC SE. We could also try to delay GW/SS deps via ABTUM a little as well if there are some rogue non-event partygoers.
Once holding at BIG begins, it becomes very important to present planes at appropriate speeds for holding. Transfer the planes to TC SE in trail and at reasonable speeds (290/300 kts is not reasonable if there is holding at BIG!). FL180 ETVAX to MSL(+1) by BIG is a tight descent - do not delay transfer before holding starts; it is very easy to trigger holding by one a/c being too high.
Finally, we are very close to finalising a new LoA with Belux (very exciting, I know!). Although this isn't the currently documented procedure, it is worth pointing out that in the new LoA we have agreed the transfer of comms point for traffic via KONAN to be no later than 10 NM east of DVR - they want to do more work, so give them the planes earlier! Again, although this isn't the currently documented procedure, the figure below shows the new KOKSY Gate (in blue) - France actually delegates a portion of airspace to Maastricht south of KONAN, so you can position outbounds a lot further south than we ever used to do. The red bit is a buffer though - so don't point further north than VABIK! Also, try not to give them any more than two abreast. Thx.
Daventry & Worthing - @Benjamin Matthews @Sebastian Rekdal @Nathaniel Leff @George Complin @Ben Wright @Matthew Burton @Nick Marinov
Daventry and Worthing will be covering TC NW and TC SW, respectively. If you get raided, put a plea out for some top-down or adjacent ATC in #request_atc_pilot or speak to me after 1845Z when I'm coordinating. Please look out for your Dover and Clacton group controllers - if non-event planes into BNN and OCK are getting 1-2 laps of the hold and then straight off whilst planes at LAM and BIG are spinning back to BRASO/TIGER, say something. This is silly.
Holding
I haven't updated the holding diagrams since CTP - hopefully all the details are still correct.
Today, please trial the following phraseology for all inbounds and let's see if we can resolve the majority of wrong direction holding:
"hold at LAM as published, left hand" / "hold at BIG as published, right hand" / "hold at BRASO as published, left hand"
I will gather your opinions on how it works after the event.
LL CTP TC-ENR HOLD v2.pdf
Questions? Fire away.
HAVE FUN!
-
By Dominic Hatje
In real life I’m a student pilot, learning to fly at the Redhill airfield which is close to Gatwick. I was hoping to get some practice through Vatsim at talking to ATC while flying circuits there and carrying out cross country flights from there in Xplane as preparation for my licence. Would anyone on the network be available as a controller at Redhill to do this? Thank you.
-
By David Gant
Although I mainly do VFR and know little about the other flavours, I have joined some friends (cockpit sharing) recently for IFR in the UK and have some questions if that's ok?
1) Does IFR traffic ever do the full instrument approach (this might not even be the correct name for it)? I realise that under ATC they will be vectored to the final approach but when not under ATC control, do they ever overfly the beacon and include an outbound leg as per the procedure charts?
2) If so, what unicom calls should be given? I'm guessing one would report: a) intention to join, and b) overhead the beacon, then what? Report final?
3) Also, if so, is it possible to request a full procedure from a quiet ATCO and what would the request be?
Thanks
-
By Harry Sugden
This post brings together links to all London (EGTT) - and Scottish (MPC) - documentation and additionally summarises the available positions, including under what conditions they may be opened.
Documentation
London (EGTT) Area vMATS Part 2 - spot a mistake, or have some feedback? Post in THIS thread. London Agreed Levels Diagrams - spot a mistake, or have some feedback? Post in THIS thread. London Sector Diagrams Current Supplementary Instructions (SIs)
SI 2020/14a - Route/STAR Clearance Responsibilities Letters of Agreement (LoAs)
Whilst the Operations Department aims to ensure the information in the vMATS is up to date, where there are conflicts, the LoA will override any procedures detailed in the vMATS Part 2, except where instructions are otherwise promulgated to the ATC Procedure Changes Forum.
VATéir (Shannon & Dublin ACCs) & VATSIM UK (London ACC) LoA Dutch vACC (Amsterdam ACC & Maastricht UAC Delta) & VATSIM UK (London ACC) LoA Belux vACC (Brussels ACC & Maastricht UAC Koksy) & VATSIM UK (London ACC) LoA French vACC (Reims, Paris & Brest ACCs) & VATSIM UK (London ACC) LoA
Sectorisation
Controller Bookings and Logging On
In line with Division Policy and guidance on the VATSIM UK website: "Members may open either a single Primary or Secondary sector, or a valid combination of Primary or Secondary sectors."
London Primary Sectors
LON_S_CTR LON_C_CTR LON_N_CTR LON_W_CTR London (MPC) Secondary Sectors
LON_E_CTR LON_D_CTR LTC_N_CTR LTC_S_CTR MAN_CTR To open any further splits of a Primary or Secondary sector, the remaining portion of that sector must be staffed too. For example, to open PC East (MAN_E_CTR) requires PC West (MAN_W_CTR) to be open, or covered by another controller. Or to open TC South East (LTC_SE_CTR), TC South West must be open or covered by another London controller.
Controllers who booked a primary or secondary sector shall have first preference over the airspace they wish to control if a split of that primary/secondary sector wishes to log on (Div Pol 3.8 k). This applies too if LON_S_CTR is booked before someone else then books LTC_S_CTR; the controller who made the first booking for LON_S_CTR has the right to swap with a booking made at a later point for LTC_S_CTR. However, booking a bandbox such as LON_SC_CTR or LTC_CTR gives the controller no right to pick which airspace they control with precedence over subsequent bookings.
Sector Names
A sector name (i.e. what we publish in documentation) will always be the most-split version - i.e. the blocks of airspace - which are collected in a Local Area Group (LAG):
South LAG: Worthing, Dover, TC South West, TC South East Central LAG: Daventry, Clacton, TC East, TC North West, TC North East North LAG: AC North, PC West, PC East West LAG: AC West
Controller Positions & Coordination Names
A position is different from a sector, in that a controller may log on to a position and be covering different sectors depending upon what other positions are open. For example:
If LON_SC_CTR and LTC_S_CTR were logged on, LON_SC_CTR would be controlling the Daventry, Clacton, TC East, TC NW, TC NE, Worthing and Dover sectors, whilst LTC_S_CTR would be controlling the TC SW and TC SE sectors. If LTC_E_CTR then logged on, LON_SC_CTR would now be controlling the Daventry, Clacton, TC NW, Worthing and Dover sectors. The names of the positions (i.e. the callsign you use for coordination) sometimes change in London.
LON_CTR (127.825) - always "(AC) Bandbox" LON_SC_CTR (132.600) - "(AC) South Central" - if the controller is left with just South/Central group sectors, as either South/Central South LAG
LON_S_CTR - "(AC) South" - if Dover is opened, then the position becomes known as "(AC) Worthing" LON_D_CTR - always "(AC) Dover" LTC_S_CTR - "TC South" - if TC South West/TC South East is subsequently opened then the position becomes known as the remainder of the two LTC_SW_CTR - always "TC South West" LTC_SE_CTR - always "TC South East" Central LAG
LON_C_CTR - "(AC) Central" - if Clacton is opened, then the position becomes known as "(AC) Daventry" LON_E_CTR - always "(AC) Clacton" LTC_E_CTR - always "TC East" LTC_N_CTR - "TC North" - if TC North West/TC North East is subsequently opened then the position becomes known as the remainder of the two LTC_NW_CTR - always "TC North West" LTC_NE_CTR - always "TC North East" North LAG
LON_N_CTR - always "(AC) North" MAN_CTR - "PC Bandbox" - if PC East/PC West is subsequently opened then the position becomes known as the remainder of the two MAN_E_CTR - always "PC East" MAN_W_CTR - always "PC West" West LAC
LON_W_CTR (126.075) - always "(AC) West"
-
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now