Oceanic Area Control

As mentioned in other pages, the Reykjavik CTA is unique in that much of it is also designated as oceanic airspace. This page outlines the procedures for providing oceanic ATC service.

NAT Oceanic Airspace

Within the Reykjavik CTA, all controlled airspace outside of the Icelandic Domestic Area is considered oceanic airspace. This airspace is designated the Reykjavik Oceanic Area (OCA). All aircraft entering the Reykjavik OCA require oceanic clearance.

Aircraft operating solely within Nuuk (BGGL) FIR below FL285, despite entering oceanic airspace, do not require oceanic clearance.

The Reykjavik OCA is one of six oceanic areas that make up the North Atlantic (NAT) oceanic airspace. The other five are Gander, Shanwick, New York, Santa Maria, and Bodo OFIR (Oceanic FIR).

Oceanic Clearance

Within the NAT airspace, aircraft are issued oceanic clearances by whichever OACC (Oceanic Area Control Center) they encounter first. Oceanic clearances issued by one OACC are valid throughout the entire NAT airspace.

E.g., for a flight entering BIRD OCA from Gander OCA, which has already received oceanic clearance from Gander, Reykjavik Control does not need to issue them further clearance.

In Iceland, Greenland, and the Faroe Islands, all departures entering oceanic airspace are issued oceanic clearance on the ground. See the Delivery and AFIS SOP pages for more information.

Airborne aircraft receive clearance from Reykjavik OACC positions (Iceland Radio or Reykjavik Control.) Clearances may be issued via either the NATTrak website or voice.

NAT Tracks

The NAT airspace uses a system of organized tracks called the North Atlantic Organized Track System (NAT OTS). While it is relatively less common for the NAT tracks to enter Reykjavik OCA (they usually remain in Gander & Shanwick OCAs), they do on occasion.

These tracks change direction twice daily, based on the prevailing flow of scheduled flights across the North Atlantic. Westbound tracks are valid from 1130-1900z, and Eastbound tracks are valid from 0100-0800z.

• For VATSIM purposes, since virtual pilots fly both directions across the North Atlantic at all times of day, it is considered acceptable to fly an “expired” track outside of its validity hours, if the latest tracks going the opposite direction have not yet been published yet.

The NAT tracks are published in the NAT Track Message. The tracks are named alphabetically based on their northerliness. E.g., Track A is the northernmost track, then Track B, etc.

The NAT Track Message will also contain a Track Message Identification (TMI) number, which helps operators & ATC verify that all flights are using the correct tracks & routings. The TMI number is the current Julian calendar date (i.e., how many days there have been in the year so far.

E.g., the 16th of January would have a TMI of 016, and the 5th of March would have a TMI of 064.

If the NAT track message has to be re-issued for any reason (e.g., correcting an error), then a letter will be added at the end of the TMI (e.g., 064A, 064B, etc.)

Aircraft on an organized track may fly at any valid level published for that track. The East/West semi-circular rule does not apply.

Clearance Phraseology (Voice)

The following section details the phraseology for providing airborne oceanic clearances via voice. For departing aircraft receiving oceanic clearance on the ground, see the Delivery SOP page.

When requesting an oceanic clearance, pilots are required to specify their requested flight level & Mach number for oceanic clearance. If pilots do not specify a requested flight level, controllers may assume that their current cleared flight level is their requested level.

Occasionally, one may receive an oceanic clearance request from an aircraft that is flying too slow for the changeover into Mach speed. In these instances, one may simply omit the Mach number from the clearance.

Random Routing Clearances

Most oceanic clearances for aircraft entering Reykjavik OCA are issued as random routing (i.e., non-NAT track) clearances, using the following phraseology:

[CALLSIGN], oceanic clearance to [DEST] via [OCEANIC ROUTING], from [ENTRY POINT] maintain [CFL], [MACH].

• The entry point is the first waypoint of the oceanic routing.
• The oceanic routing is the portion of the aircraft’s route within the NAT oceanic airspace (not just Reykjavik OCA, but all of the NAT OCAs – Gander, Shanwick, etc.)
  • If an aircraft will remain in oceanic airspace for the rest of its entire flight, then its oceanic routing is equivalent to the entire remainder of its flight plan routing (starting from its entry point all the way to its final flight planned waypoint.)

For example:

🎧 SAS142, oceanic clearance to Seattle via IPTON 66N010W 69N020W 70N030W 71N040W 71N050W 71N060W NADMA, from IPTON maintain FL320, Mach .82.

If one is giving oceanic clearance to an aircraft that has already entered oceanic airspace, as is often the case when just logging onto a position, the aircraft may simply be instructed to “maintain FLXXX” (without the “from [ENTRY POINT]” condition.)

NAT Track Clearances

In the rare occasion that Reykjavik OACC must issue an oceanic clearance for an aircraft on a NAT track, then the phraseology is as follows:

[CALLSIGN], oceanic clearance to [DEST], via [TRACK], from [ENTRY POINT] maintain [CLEARED FL], [MACH].

For example:

🎧 SAS255, oceanic clearance to Los Angeles via track A, from RATSU maintain FL350, Mach .81

For Reykjavik OAC (unlike Gander & Shanwick), it is not required to include the TMI number when giving the clearance. However, pilots are expected to include the TMI number when they read back any oceanic clearance via a NAT track. For example:

🧑‍✈️ SAS255 is cleared to Los Angeles via track A, TMI 83, from RATSU maintain FL350, Mach .81.

If the pilot does not provide the TMI number in their readback, then controllers should confirm it with the pilot while verifying their readback.

Amended and Conditional Clearances

Controllers may specify a different routing, cleared level, or Mach speed in an oceanic clearance if necessary for separation, flow control, traffic management, etc. Such clearances are known as amended clearances.

In these instances, the oceanic clearance should be issued using the phraseology: Oceanic clearance to [DEST] with an amended [route/level change/speed change]… (as appropriate)

For example:

🎧 NOZ114, oceanic clearance to Keflavik with an amended route and speed change, via RATSU BARKU ASRUN, from IPTON maintain FL300, Mach .84.

Controllers may also instruct an aircraft to cross a given waypoint either at, at or before, or at or after a specified time. Such clearances are known as conditional clearances. For example:

🎧 BAW80KA, oceanic clearance to Keflavik via RATSU BARKU ASRUN, from RATSU maintain FL360, Mach .84, cross RATSU at or before 1732z.

If the pilot must climb, descend, change speed, etc. to fulfill these conditions prior to entry into oceanic airspace, it is their responsibility to make those requests from domestic ATC prior to entering Reykjavik OCA.

Procedures Within Oceanic Airspace

The Reykjavik CTA, through a combination of secondary radar and ADS-B, has full ATS surveillance coverage enroute. Therefore, aircraft in oceanic airspace may be controlled using normal ATS surveillance procedures (including vectoring, speed change, etc.)

Operation Without Assigned Fixed Speed (OWAFS)

Under a recent initiative in North Atlantic airspace known as Operation Without an Assigned Fixed Speed (OWAFS), controllers may now provide more speed flexibility to pilots in oceanic airspace.

All oceanic clearances shall include an assigned Mach number (or airspeed). After oceanic entry, aircraft may be instructed to "RESUME NORMAL SPEED" on a tactical basis. This allows aircraft to fly an optimum cost index (ECON) speed. ATC must be informed if the speed changes by +/- 0.02 Mach or more from the last assigned Mach number.

E.g., if an aircraft is cleared at Mach .80, and it is instructed to “resume normal speed,” it may maintain anywhere between Mach .78 to Mach .82 without needing to inform ATC.

It is recommended that OWAFS is only applied to aircraft whose planned minimum longitudinal
separation from other aircraft is 60NM or greater. Longitudinal separation must be monitored and a
fixed Mach number may be re-assigned if necessary.