Oceanic » Clearance

General

• There are three elements to an Oceanic Clearance: Route, Speed and Level. These elements serve to provide for the three basic elements of separation: lateral, longitudinal and vertical.
• Oceanic Clearances are required for all flights within NAT controlled Airspace (at or above FL55).
• To assist the OAC in pre-planning optimum airspace utilisation, when requesting an oceanic clearance the pilot should notify the OAC of the maximum acceptable flight level possible at the boundary, taking into account that a climb to the assigned oceanic flight level must be achieved prior to entering oceanic airspace and normally whilst the aircraft is within radar coverage.
• At some airports situated close to oceanic boundaries or within the NAT Region, it may be necessary to obtain the Oceanic Clearance before departure.
• The Oceanic Clearance should be requested at least 30 minutes before Oceanic Entry Point.
• After obtaining and reading back the clearance, the pilot should monitor the forward estimate for oceanic entry, and if this changes by 3 minutes or more, the pilot must pass a revised estimate to ATC.
• If pilots have not received their Oceanic Clearance prior to reaching the OCA boundary, they must contact Domestic ATC and request instructions to enable them to remain clear of Oceanic Airspace whilst awaiting such Clearance.
• The Oceanic Clearance issued to each aircraft is at a specified flight level and cruise Mach Number.
• An example of a pilot voice request for Oceanic Clearance is as follows:
  • ACA865 request oceanic clearance via Track Bravo. Estimating PIKIL at 1131. Request Mach .80, Flight Level 350, able Flight level 360

Contents of clearances

An abbreviated clearance is issued by Air Traffic Services when clearing an aircraft to fly along the whole length of an Organised Track. When an abbreviated clearance is issued it includes:

1. clearance limit, which will normally be destination airfield;
2. cleared track specified as "Track" plus code letter;
3. cleared flight level(s);
4. cleared Mach Number; and

A typical example of such a clearance is as follows:

• ACA865 is cleared to Toronto, via PIKIL, NAT track Bravo. From PIKIL maintain Flight Level 350, Mach .80

Procedures exist for an abbreviated read back of an Oceanic Clearance. The flight crew will confirm that they are in possession of the current NAT Track message by using the TMI number (including any appropriate alpha suffix) in the read-back of the Oceanic Clearance, as follows:

• ACA865 is cleared to Toronto, via PIKIL, NAT track Bravo, TMI 115. From PIKIL maintain Flight Level 350, Mach .80

If the TMI number is included in the read-back there is no requirement for the pilot to read back the NAT Track co-ordinates even if the cleared NAT Track is not the one which was originally requested. If any doubt exists as to the TMI (see fuller explanation of this term under "NAT Track Message / TMI Number" on this page) or the NAT Track co-ordinates, the pilot should request the complete track co-ordinates from the OAC. Similarly, if the pilot cannot correctly state the TMI, the OAC will read the cleared NAT Track co-ordinates in full and request a full read back of those co-ordinates.

For aircraft cleared by Shanwick OAC on random routings in the NAT Region the present procedure of reading the full track co-ordinates as part of the Oceanic Clearance and requesting from the pilot a full read back of the co-ordinates is expected to continue. Gander and Reykjavik OACs may, however, issue clearances for random routings which specify "via flight plan route". Nevertheless, in all circumstances regarding random route clearances, pilots are required to read back the full track co-ordinates of the flight plan route, from the oceanic entry point to the exit point.

Oceanic clearance examples

Clearance flying a NAT track

• ACA865 request oceanic clearance
• ACA865 pass your message
• ACA865 request clearance via Track Bravo. Estimating PIKIL at 1131. Request Mach .80, Flight Level 350, able Flight Level 360
• ACA865 is cleared to Toronto via PIKIL, NAT track Bravo, from PIKIL maintain Flight Level 350, Mach .80
• ACA865 is cleared to Toronto via PIKIL, NAT track Bravo, TMI 115*, from PIKIL maintain Flight Level 350, Mach .80
• ACA865, read-back correct

(Note: coordinates shall be spoken as "5 4 north 0 2 0 west". Times shall be spoken as "1 1 3 1", and not "eleven thirty one")

* If the TMI number is included in the read-back there is no requirement for the pilot to read back the NAT Track co-ordinates even if the cleared NAT Track is not the one which was originally requested. If any doubt exists as to the TMI (see fuller explanation of this term under "NAT Track Message / TMI Number" on this page) or the NAT Track co-ordinates, the pilot should request the complete track co-ordinates from the OAC. Similarly, if the pilot cannot correctly state the TMI, the OAC will read the cleared NAT Track co-ordinates in full and request a full read back of those co-ordinates.
You can find the current NAT tracks and TMI number by clicking here.

Clearance flying a random route

Sometimes you may be flying on a "random route" instead of a NAT track. It's more or less the same as above, except that you need to read the full route instead of "Track A".

• ACA865 request oceanic clearance
• ACA865 pass your message
• ACA865 request oceanic clearance via MALOT 54N020W 56N030W 57N040W 56N050W JANJO. Estimating MALOT at 1131. Request Mach .80, Flight Level 350, able Flight Level 360
• ACA865 is cleared to Toronto via MALOT 54N020W 56N030W 57N040W 56N050W JANJO, from MALOT maintain Flight Level 350, Mach .80
• ACA865 is cleared to Toronto via MALOT 54N020W 56N030W 57N040W 56N050W JANJO, from MALOT maintain Flight Level 350, Mach .80
• ACA865, read-back correct

(Note: coordinates shall be spoken as "5 4 north 0 2 0 west". Times shall be spoken as "1 1 3 1", and not "eleven thirty one")

Note: a full read-back of the clearance is always required.

If you are cleared via "flight plan route", you, the pilot, still need to read back the complete routing for your oceanic flight.

NAT Track Message / TMI Number

The originating OAC identifies each NAT Track Message, within the Remarks section appended to the end of the NAT Track message, by means of a 3-digit Track Message Identification (TMI) number equivalent to the Julian calendar date on which that OTS is effective. For example, the OTS effective on February 1st will be identified by TMI 032. (The Julian calendar date is a simple progression of numbered days without reference to months, with numbering starting from the first day of the year.) If any subsequent NAT Track amendments affecting the entry/exit points, route of flight (co-ordinates) or flight level allocation are made, the whole NAT Track Message will be re-issued. The reason for this amendment will be shown in the Notes and a successive alphabetic character, i.e. 'A', then 'B', etc., will be added to the end of the TMI number (e.g. TMI 032A).