After reading this guide you should be able to:
The Organised Track System comprises of tracks. North Atlantic Tracks that allow aircraft to transit from one side of the North Atlantic to the other.
Now, what are the North Atlantic Tracks? In essence, they are one-way airways. The tracks are defined and governed by two factors:
The latter largely is affected by the former.
The jetstream is a strong upper-level wind which is poised at the edge of the troposphere. It can reach speeds of 150 knots easily. It blows generally from west to east, hence it is aimed to keep the Westbound Tracks out of it as much as possible. By contrast the Eastbound Tracks are aligned to be in the tracks, thus maximising ground speed.
The tracks are calculated and published twice daily by the control centres at Gander (in Newfoundland) and Shanwick (in the UK and Ireland).
The airlines flying the Atlantic regularly send Preferred Route Messages to Shanwick and Gander indicating their requests. By a rule Shanwick issues the westbound tracks, Gander does the eastbound tracks.
Are there other control centres involved?
Yes, there are, the other key players are Santa Maria, New York, Reykyavik and Bodo, Norway.
The tracks are labelled A-M (No I), A is ALWAYS the northernmost track. Not all track letters are used every day, the exact number of NATs depends on the day of the week and the season as the exact number of flights vary.
Notice how the Tracks are arranged to keep away from the brunt of the Jetstream (bold yellow line at FL340)
Eastbound tracks are labelled P-Z, this is the maximum scope of tracks, Tracks P, Q, R and S are not always used, this depends on the day of the week, the season and expected traffic volume.
The southern most track is always Z.
Notice the tracks are laid into the jetstream to maximise tailwind use:
Having seen the general picture, let's have a look at how the tracks are composed. To find out what the tracks are there are several ways and means:
The track separation usually is one degree of latitude parallel to one another, however following a newly introduced trial, we are now working to a reduced separation which can be seen in the example flight that we are doing. Better surveillance now permits our tracks to be as close spaced as half a degree of latitude, which equates to approximately 30nm. More on that a little later, as it affects simming.
A SUNOT 58/20 60/30 61/40 62/50 MAXAR WEST LVLS 310 320 330 350 360 370 380 390 EUR RTS WEST NIL NAR NIL
A track always consists of:
Above, we can see that our OEP is SUNOT , our coordinate waypoints are: 58/20 60/30 61/40 62/50 and our exit fix is MAXAR.
WEST LEVELS are the available flight levels, in this case you can use FL310-FL330 and FL350-FL390. Why not FL340? In some cases, it is necessary to block off a certain flight level to permit traffic to cross the NATs.
EUR RTS usually contain a waypoint or two if it is determined to be necessary to force traffic coming on/off the NATs via a certain waypoint. With the free route airspace in Ireland, this is very much a relic of the past, normally you can route fairly liberally to/from wherever needed.
R RIKAL 53/50 55/40 56/30 57/20 SUNOT KESIX EAST LVLS 320 330 340 350 360 370 380 390 400 WEST LVLS NIL EUR RTS EAST NIL NAR N505A N503A-
NAR stands for North American routes. These are feeder roads to and from the NATs. At times it is necessary to mandate the use of certain routes to certain NATs to harmonise the traffic getting on and off. Although this has become seldom, the NAR is still a great tool to get yourself to/from the NAT to or from any of the US eastern seaboard. These can be viewed on skyvector.com
As you may have seen on the websites and in the message, there is a time constraint given. And the time constraint is the deadline to cross 30° West longitude.
No. The NATs are generally good to use for flights in between North and Central Europe and a corridor along the eastern US and Canada with the cut-off point at a line approximately just west of Chicago and a southern border around Washington DC. To get to another destination you need a random routing, which will be explained later in this guide.
Head over to SimBrief.com and enter all flight and aircraft info. SB will automatically generate a route based on our paramaters given.
Within the map viewr we can then toggle on NATs East and Significant weather overlays. SB also allows your to turn on wind-barb chart overlay for different FLs.
As we can see the proposed route matches with the expect active tracks for the time of flight.
In this case we will plan on using track U with the OEP JOOPY
Note: It is important to generate your final OFP/Briefing just before the departure. NAT tracks change daily and you can end up filing for a NAT that is no longer in use from the time you did your FP briefing. Simbrief does not accurately provide the correct NAT for the appropriate time of day in the future.
Let's bring up Track U and see what it tells us:
U JOOPY 49/50 51/40 53/30 54/20 DOGAL BEXET EAST LVLS 340 350 360 370 380 390 400 WEST LVLS NIL EUR RTS EAST NIL NAR N269A N263A N261A
We can now see the full oceanic route of track U as well as all available FLs (340-400)
In this case we will need to insert the oceanic coordinates as actual route waypoints since we are no longer using the Oragnized Tracks. This is then considered Random Routing.
Once we are happy we can proceed to generate the OFP. SimBrief will the present us with the final route. By default the map viewer will also show us our ETOPS alternate airports.
In our case:
Final step is to select Prefile on Network and choose IVAO. This will lead us to fpl.ivao.aero with our entire FP pre-filled, now we simply click Submit FPL.
To obtain clearance we can go two ways, voice or text. Whichever way we choose we stick to it.
Assuming we are on UNICOM prior to entry, we can simply switch to Shanwick or Gander Radio. If we are under control by any controller, we need to request to leave to get our clearance. Always check with the controller, on event days he will also be able to tell you who you need to call for clearance. The controller will send you to oceanic as soon as practical, after the clearance you need to return to him.
Now, when you tune in to Gander/Shanwick, take a few moments to collect all the information you need. The controller will require the following details:
You can retrieve these details from the F-PLAN page in an Airbus or the LEGS page (by selecting RTE Data) in a Boeing.
Pilot: "Shanwick Radio, (Callsign) with request."
ATC: "(Callsign), Shanwick. Hello, pass your message."
Pilot: "(Callsign) request clearance to Montreal via Track E, Flight Level 380, Mach .85. Estimating JOOPY at 1125z. TMI 097."
ATC: "(Callsign), cleared to Montreal via Track E, Flight Level 380, Mach .85."
Pilot: "Cleared to Montreal, Track E, FL380, Mach .85, (Callsign)"
ATC: "(Callsign), readback correct, make next position report at JOOPY with Shanwick on (freqeuncy). Return to previous frequency approved"
Now that we have our clearance, we return either to UNICOM or the previous controller.
Important: if the estimate for our entry point or indeed any point during the crossing changes by more than 3 minutes, we must inform the controller immediately, as a new clearance may become necessary.
Here is the reason: The network allows pilots only to contact stations to which you are in range, this range is a circle of 1000nm around a centerpoint. 1000nm does not allow for complete Coverage of the airspace and a buffer to get the clearance. If you cannot tune Shanwick, please send the controller a chat message, he will move the centrepoint for you to be able to tune.
If your flight time to your entry point is less than 30 minutes, and you are on the ground, you must request clearance on the ground using your estimated time for your entry waypoint. Once airborne, check this estimate and revise with the controller, as necessary.
The flight is progressing nicely and Speedbird 172 has reached JOOPY on the specified time. ATC gives the following instruction:
ATC: "Speedbird 172, report JOOPY to Gander Radio on 127.850, good day."
Pilot: "Report JOOPY to Gander Radio on 127.850, Speedbird 172, good day."
When tuning in, remember to take some time to listen for other radio traffic. Any traffic on the frequency consists of a position report, a readback by the controller, and the confirmation by the pilot that the readback is correct. There is NO POINT blabbing in, you will need to wait in line to be processed and stepping on a readback will only prolong your wait and have a hit on the efficiency.
Write down your details on a piece of paper, or use this document to help you put down all the Information necessary and make sure you have all your data.
The data required for a position report is located on the following FMC Pages:
A position report consists of:
Our tutorial flight position report therefore looks like this:
Speedbird 172 (callsign) has passed JOOPY (Position) at Time 03:26 Zulu (Time), flight level 350, Mach decimal 85, Estimating 4-9 North 3-0 West at 00:50 Zulu (Name+ETA next waypoint), 5-1 North 4-0 West next (NAME ONLY of Waypoint thereafter).
Pilot: "Gander, hello, Speedbird 172 heavy, position report."
ATC: "Speedbird 172 heavy, Gander, roger, standby."
Just wait patiently for the controller to be ready to take your details, he will call you.
ATC: "Speedbird172, pass your message."
Pilot: "Speedbird 172 passed JOOPY at 0-3-2-6, FL 350, Mach decimal 85, estimating 4-9 North 3-0 West at 0-0-5-0, next 5-1 North 4-0 West."
ATC: "Speedbird 172 has passed JOOPY at 0-3-2-6, FL 350, Mach decimal 85, estimating 4-9 North 3-0 West at 0-0-5-0, next 5-1 North 4-0 West."
Pilot: "Speedbird 172 heavy, readback correct."
The same principle applies at every waypoint you pass, or latest 45 minutes after the last position report. Especially on random routings the fixes may be further apart than 45 minutes.
SELCAL, or 'Selective Calling', is like a phone number. It allows controllers to reach a pilot even if he is not actively listening on frequency. Over the Atlantic in real life, voice communication is handled over HF radio as VHF does not have enough range to cover the Atlantic. HF radio quality is poor, lots of background noise, which makes monitoring the frequency very tedious on the ears.
SELCAL allows the pilot not to have to continuously monitor the frequency.
How is SELCAL generated?
Via a combination of four letters. Valid characters are:
https://www.avdelphi.com/selcal.html Preview your SELCAL code.
How do I use the SELCAL?
Following the first position report, the pilot can request a SELCAL check.
Pilot: "Speedbird 172, readback correct. Request SELCAL check: Delta Golf Foxtrot Papa".
ATC: "Roger, standby".
The controller will activate the SELCAL and send it, a two-tone sound indicates a good SELCAL check.
Pilot: "Speedbird 172, SELCAL received."
If no SELCAL sound is heard:
Pilot: Speedbird 172, negative SELCAL."
If the SELCAL is OK you may turn down the volume, you have to remain within general earshot, however. If the SELCAL fails, you must remain on voice.
It is a common request. You can by all means ask for a step-climb or speed change. However, it is NOT GUARANTEED that you can get one. To get a step climb there needs to be at least a window of 15 minutes on the crossing levels to allow for it. It is therefore wise to climb as high as possible before oceanic entry, it is less fuel-burning to fly above your optimum for a while than below it. That way you can make another step climb at the end of the Atlantic crossing to compensate for it.
There are multiple ways to request a step climb or speed change, you can ask for it direct, or you add it on your position report:
Pilot: "Speedbird 172 passed JOOPY at 0-3-2-6, FL 350, Mach decimal 85, estimating 4-9 North 3-0 West at 0-0-5-0, next 5-1 North 4-0 West. Request FL370 at 0120 Zulu"
Pilot: "Speedbird 172, Request FL370 at 4-9 North 3-0 West "
ATC: "Speedbird 172, Climb FL370, report reaching."
You still must explicitly be cleared to climb or descend however and MUST NOT do so without ATC clearance.
The bottom line:
You must not however, change anything on your clearance (unless with the permission of the controller), this includes speed (with the exception of OWAFS, as detailed below) and level changes.
Recently, a new trial has been running over the Atlantic called "Operations Without An Assigned Fixed Speed", OWAFS for short. Before this trial, you needed to pick a speed within .01 of Mach and stick with it. This new operation allows you to fly the ECON speed in your FMC, which varies over time, usually reducing before increasing again after a step-climb.
To request this:
IMPORTANT: IF YOUR OWAFS speed changes by more than 0.02 Mach, it is your DUTY to inform the controller.
Passing 40°W going eastbound or 20°W going westbound, if there is more than one controller, you will be instructed to make the next position report to Shanwick or Gander Radio respectively.
Remember, you need to remain on the current frequency until you are ready to make your next position report at 30°W; then you may change to the next frequency.
When you pass 20°W going eastbound or 50°W going westbound ATC will pass you information on which controller to contact next. When you contact that controller, you will be given a squawk, once you are identified no further position report will be needed and you continue on your merry way.
Why do we need random routings?
As the NATs are not always stable there are exceptions and on occasions even flights to/from Los Angeles and San Francisco can be routed over the NATs. Especially at night it can be worthwhile to allow for a longer route to benefit from the jetstream.
Flights to Miami, the Texan coast, the Caribbean (Juliana, TNCM) the Central Americas and Northern South America will most certainly however fly via a random routing.
Now, what is a random routing?
A random routing is a route chosen by the pilot which will usually try and follow the great circle (shortest distance across our planet, remember?) as closely as possible. We therefore can liberally plan a routing on our own.
We must observe but a few rules:
DO NOT INSERT "DCT" BETWEEN COORDINATES ALONG THE TRACK.
The correct routing portion for the Oceanic airspace should look like this:
… SEPAL DCT 46N015W 45N020W/M082F360 41N030W 36N040W/M082F380 29N050W DCT RKDIA/N0472F380 …
This route is a mere example, please make sure you plan your own routing on the day you fly.
The procedure for obtaining a random routing clearance is very similar to a NAT. There are however two key differences:
Pilot: "Shanwick, good afternoon, Air France 3510 heavy."
ATC: "Air France 3510 heavy, Shanwick, pass your message."
Pilot: "Air France 3510 heavy, request Juliana via random routing, LAPEX, 46 North 15 West, 45 North 20 West, 41 North 30 West, 36 North 40 West, 29 North 50 West, RKDIA, FL320, Mach decimal 85, estimating LAPEX at 0955z."
ATC: "Air France 3510 heavy, cleared to Juliana via random routing LAPEX, 46 North 15 West, 45 North 20 West, 41 North 30 West, 36 North 40 West, 29 North 50 West, RKDIA, FL320, Mach decimal 85."
Pilot: "Air France 3510 heavy, cleared to Juliana via random routing LAPEX, 46 North 15 West, 45 North 20 West, 41 North 30 West, 36 North 40 West, 29 North 50 West, RKDIA, FL320, Mach decimal 85."
ATC: "Air France 3510 heavy, readback correct, return previous freq. Report LAPEX."
Pilot: "Wilco, Air France 3510 heavy."
Pilot: "Shanwick, Air France 3510 heavy, position report."
ATC: "Air France 3510 heavy, pass your message."
Pilot: "Air France 3510 heavy, Passed LAPEX at 0955Z, FL320, Mach decimal 85, estimating 46 North 15 West at 1020Z, 45 North 20 West is next."
ATC: "Air France 3510 heavy Passed LAPEX at 0955Z, FL320, Mach decimal 85, estimating 46 North 15 West at 1020Z, 45 North 20 West is next."
Pilot: "Readback correct, Air France 3510 heavy."
Always fly the clearance as directed by the controller. It may differ from what you requested.