VATSIM-UK - Oceanic Control Procedures
Shanwick Oceanic Control Area
Control Procedures
Control Procedures
Airspace
Shanwick Oceanic manages the airspace over the Eastern Atlantic between 30°W and landfall with the UK and Ireland, and from 45N to 61N. The Oceanic Control Area (Class A airspace) extends from FL55 up to Flight Level 660. Flight Information Service may be available for flights outside these levels! Shanwick uses the callsign EGGX_FSS and frequency of 131.80 mhz. West of 30°W is covered by Gander Oceanic, callsign CZQZ_FSS, and frequency of 131.70 mhz. Because of existing agreements with VATCAN, when controlling Shanwick you may also cover Gander if that is not staffed. During special events or fly-in's, Shanwick will be split up to form EGGX_H_FSS on 131.80 mhz (FL360 and above) and EGGX_L_FSS (FL350 and below) on 131.85 mhz. Pilots are permitted to use 4X acceleration within the OCA subject to ATC clearance.
Shannon Oceanic Transition Area (SOTA)
The airspace to the south of Shannon FIR from 8W to 15W used to be part of the Shanwick OCA. Since Shannon (EISN_CTR) has radar coverage in this area, that section of airspace is delegated to them WHEN EISN CTR IS ON LINE.
If EISN_CTR is not on line but EGGX_FSS is on line then EGGX will assume responsibility for the SOTA under normal Oceanic control procedures.
NAT Track System
Because of the vast distances to be covered, the lack of navigational aids, and the weather conditions over the North Atlantic, a system of daily tracks exists for aircraft to plan their flights utilising the best flight levels and winds to make their crossings. In the real world you will find most flights from America to the UK (Eastbound) will take place during the night, whilst UK to America (westbound) tend to occur during the day. This is to take advantage of night noise restrictions at the major airports, the flight leaves the US/Canada before the night jet ban comes into effect, taking 7+ hours for the crossing, plus a 5 hour time difference between the (Eastern) USA and UK, arriving in the morning after the night jet ban has ended. The current NAT Tracks are available here. ALL pilots are urged to consult the current tracks to plan their route across the Atlantic. A sample track signal is shown on the NAT Tracks page together with notes on its use.
Clearances and Flight Plans
Clearances and flight plans for aircraft crossing the Atlantic are a lot more detailed than for aircraft flying domestically.
Once a pilot has copied his/her normal route clearance they must contact Oceanic and obtain Oceanic Clearance prior to departure if at an airport west of 3 W. This may be done by Private Chat Message or (if requesting Oceanic clerance before start, which is strongly advised) by voice, remembering that if they have already established communication with ATC at airfield of departure then ATC should be advised that the pilot is going off frequency for a short while to get Oceanic clearance.
Clearance should be as follows :-
PILOT:"Shanwick Oceanic, BAW175 request clearance to KJFK"
SHANWICK: "BAW175, Pass your message"
PILOT: "BAW175, Request KJFK via NAT Charlie DOGAL 54/20 54/30 52/40 49/50 LOGSU VIXUN at FL380 and mach 0.84 estimate DOGAL 11:40 BAW175"
SHANWICK: "BAW175, Cleared as filed along track charlie to KJFK at FL380 Mach 0.84, cross DOGAL not before 11:35, clearance expires DOGAL 11:45"
The time restrictions MUST be strictly observed. Should a pilot discover, after departure, that the DOGAL estimate is outside the tolerance given (11:35 to 11:45) theyMUST contact Shanwick again for a revised clearance.
If departing from an airfield east of 3W wait until airborne and send clearance request in a private chat message to Shanwick OCA.
It is self evident that the flight plan MUST contain details of the EXACT route through the OCA. 55N10W dct 54N50W is NOT ACCEPTABLE, neither is WPT1 WPT2 WPT3 etc!!! you would be surprised how many flight plans look exactly like that!
Seperation Standards
Since we do not have radar then procedural separation must be applied.
Vertical
Aircraft in level flight 1,000' apart (up to and including FL400) are separated, above FL400 2,000' vertical separation shall be applied. Supersonic flights require 4,000 feet vertical separation from ANY other flight if no other form of separation (lateral or longitudinal) exists. This applies at ANY level for aircraft at supersonic speeds. Subsonic flights using time acceleration are NOT subject to this requirement.
Lateral
Aircraft must be kept apart by 60 Nautical Miles laterally if at the same level on different tracks. One degree of latitude is 60 NM. Parallel tracks which are spaced apart by one degree, and which change latitude by no more than 2 degrees over a longitude of ten degrees are deemed to be Separated. i.e. tracks from 52N20W to 54N30W and 53N20W to 55N30W are separated. 55N10W to 58N20W and 56N10W to 59N20W are NOT separated. Nat tracks are normally defined so that they do not change latitude by more than 2 degrtees for each 10 degrees longitude difference.
Longitudinal
Aircraft on the SAME TRACK at the SAME LEVEL must be kept TEN MINUTES flying time apart, so an aircraft passing 57N20W at FL360 must not be followed by another at the same level on the same track until ten minutes have elapsed after the first one passed that point. Aircraft on CROSSING TRACKS at the SAME LEVEL must be FIFTEEN minutes apart at the point where the tracks cross.
Speed Differences
Obviously if an aircraft cruising at M0.80 is followed by another at M0.84 then ten minutes at Ocean entry will soon be caught up! Apply the following rule of thumb:-
- Slow followed by fast. ADD one minute to the basic ten for every increase of 0.01 Mach number of the second aircraft. M0.80 followed by M0.84 requires FOURTEEN minutes at ocean entry same track same level.
- Fast followed by slow. For every M0.02 speed difference one minute may be SUBTRACTED from the basic ten minutes at ocean entry, down to an absolute minimum of five minutes separation at ocean entry. M0.84 followed by M0.80 requires a minimum of EIGHT minutes separation at ocean entry same track same level.
- If two aircraft at different speeds are entering the OCA at the same point but folowing tracks which will be separated by 60NM ten degrees of longitude after entry then the INCREASE above is NOT required. The REDUCTION above may still be applied. Of course if this situation occurs inside the OCA (as opposed to at entry) then they are considered to be on crossing tracks and the FIFTEEN minute rule applies. There is NO reduction to the fifteen minute rule for fast followed by slow on crossing tracks.
It is perfectly acceptable to apply time restrictions to an aircraft's oceanic clearance., e.g. add "Cross GOMUP not before 15:45" even for an aircraft already in the air who has given an estimate for OCA entry.
Opposite Directon
Obviously you cannot have two aircraft opposite direction to each other at the same level same track! However the following is included in order that it is possible to determine the separation requirement for aircraft wishing to climb/descend through the level of another aircraft opposite direction, whether on the same track or crossing tracks opposite direction. Vertical separation must be established before the aircraft reach a position calculated to be 30 minutes flying time BEFORE the position/time at which it is estimated that they will pass one another, and must continue to exist until 30 minutes AFTER they are estimated to have passed. If it can be positively established that they have passed, by both having reported passing the same Oceanic Reporting Point then the separation may be reduced to 10 minutes after they are known to have passed each other.
EXAMPLE. Two aircraft, (a) routing 55N10W 56N20W 57N30W (b) routing 56N30W 56N20W 56N10W. (a) estimates 56N20W at 1234 and 57N30W at 1304, (b) estimates 56N30W at 1224 and 56N20W at 1254. Inspection and calculation indicates that they will both be roughly one third of the way from 20W to 30W (or two thirds of the way from 30W to 20W) at roughly the same time (1244) so vertical separation must exist from 1214 until 1314. Once (b) has reported past 20W (at 1254 hopefully) we have established the pass and one or other may climb/descend through the other aircraft's level after 1304 (ten minutes after they are KNOWN to have passed).
Requested Route/Level Unavailable
If it is not possible to clear the requested route/level (because there is another aircraft in the way!) pilots will be offered an alternative track, or a different Flight Level. They should then specify which they would rather have, and what that preferred alternative would be, eg request track Delta FL380 or request track Charlie FL360. Oceanic will try to accomodate this request, and if this is also not available they will suggest an alternative which is available, it is the pilot's responsibility to check that this is acceptable.
Mach Number
All clearances for jet aircraft will include a cleared Mach number. Pilots MUST maintain speed within 0.01 Mach of this figure, i.e. in the clearance above speed MUST be maintained between M0.831 and M0.849. Speed SHOULD be contained within M0.005 of the specified figure (in the example M0.835 to M0.845). Faliure to do so will result in erosion of separation and may result in you being further restricted in Mach number as you progress across the OCA.
RVSM
Shanwick OCA is notified as RVSM airspace, vertical separation of only 1,000' is used up to and including FL400. It is essential that pilots not only use the autopilot altitude hold but set the altimeter to 1013.2 Mb (29.92 in Hg) and set the correct level in the autopilot.
THERE COULD BE SOMEONE COMING THE OTHER WAY 1,000' ABOVE OR BELOW!
In RW Oceanic control, due to the large diurnal traffic flow (they all fly west during the day and east at night) all levels will be available during the heaviest traffic flow. This does not happen on VATSIM, so normal RVSM semi-circular flight levels apply, i.e. even levels westbound, odd levels eastbound.
Navigation
Modern navigation systems are able to pinpoint their location with great precision without relying on VOR and DME equipment. The same is required of the Flight Sim pilot. MSFS GPS, FSNAV and many other flight sim navigation systems are able to navigate across the Atlantic with equal precision. Pilots are REQUIRED to be within 2 miles of cleared track AT ALL TIMES. Should any systems failures prevent this they must notify Oceanic immediately.
Pilots with suitably equipped navigation systems may REQUEST a lateral offset to their track which MUST NOT exceed 2 NM to the RIGHT of the cleared track. This procedure may NOT be implemented unless specifically cleared by ATC. Offsets to the LEFT of track are not permitted. If a track offset has been requested and approved then the aircraft MUST be maintained within 2 NM of the cleared offset track.
Position Reports
Due to the lack of radar over the Atlantic (in real life there is none) pilot position reports are important. Pilots should report to ATC at least when :-
- Passing a waypoint e.g. 52/40
- Changing flight level
- Performing a large change in heading
- 45 minutes has passed since last contact
- Reaching or leaving Oceanic Airspace
- Connecting up to the internet into Oceanic airspace
and these report should be like this:-
PILOT: SHANWICK (CALLSIGN) POSITION REPORT
SHANWICK: (CALLSIGN) SHANWICK, GO AHEAD
PILOT: SHANWICK (CALLSIGN) REPORTING 53N50 AT 2208Z, FL350 Mach decimal 82, ESTIMATING 55N40 AT 2410Z 56N30 NEXT.
SHANWICK: READS BACK THE POS REPORT
NOTE ALL Oceanic position reports must be in CURRENT UTC, regardless of the time displayed on the aircraft's FS clock!
Handoff Procedures - Shanwick
Gander
All aircraft should be handed off at or before 30W. Check with CZQX_FSS via private chat. It should be on 131.700
Scottish/Shannon/London/France control
All aircraft are to be handed off at odd flight levels.
Due to the procedural nature of Oceanic control flights should expect to maintain their allocated cruise level for the duration of the Atlantic crossing. Level changes in Oceanic airspace are an EXCEPTION not the rule. There is plenty of time to descend from cruise level once pilots have left Oceanic airspace.
Iceland
Aircraft on POLAR routes or en route to Iceland need to be handed off to BIRD_CTR or BIRD_FSS before 61North. Check via private chat that the cleared FL is OK.
South Atlantic
Aircraft which will cross 45N need to be handed off to Santa Maria Oceanic ( LPPO_FSS ) or New York (KZNY_FSS) before they leave the Sector. Check via private chat box re Flight Level required.
Handoff Procedures - Gander
Gander
Many flights will first cross into Canadian airspace via Gander, and should be handed off to CYQX or YQX_CTR on 133.15 at even Flight Levels
Moncton
Just south of Gander lies Moncton, and aircraft should be handed off to MCN_CTR on 134.25 at even Flight Levels.
Tips and Tricks
- Note: Remember to set your visibility centre (.vis command in ASRC) to somewhere in the middle of the airspace. If controlling Gander as well as Shanwick this will be about 53N30W.
- Note: Connect as FSS in the "connect" dialog box, and set your visibility range to maximum.
- Note: Keep a pen and paper handy, you will need them to write down the clearance request details and the position reports.
- DON'T CHEAT by looking at the radar screen to achieve separation. You are, of course, allowed to look at the screen to see what aircraft are about to enter your airspace wihout calling you!!
[Page last modified 13/07/2009]
[06:00 - 22:00] EGLC_TWR