Polar Track Structure (PTS)

Other Routes within NAT MNPS Airspace

Other routes within NAT MNPS Airspace (illustrated in Figure 9.4) are as follows:

(1)* ‘Blue Spruce’ Routes, established as special routes for aircraft equipped with only one serviceable LRNS. State approval for MNPS operations is required in order to fly along these routes.

(2)routes between Northern Europe and Spain/Canaries/Lisbon FIR. (T9*, T13 and T16);

(3)* routings between the Azores and the Portuguese mainland and between the Azores and the Madeira Archipelago;

(4)* routings between Iceland and Constable Pynt on the east coast of Greenland and between Kook Islands on the west coast of Greenland and Canada

(5)special routes of short stage lengths where aircraft equipped with normal short-range navigation equipment can meet the MNPS track-keeping criteria (G3 and G11). State approval for MNPS operations is required in order to fly along these routes.

Note: *routes identified with an asterisk in sub paragraphs (1), (2), (3) and (4) above may be flight planned and flown by approved aircraft equipped with normal short-range navigation equipment (VOR, DME, ADF) and at least one approved fully operational LRNS.

Route Structures Adjacent to NAT MNPS Airspace

North American Routes (NARs)

The North American Routes (NARs) consist of a numbered series of predetermined routes which provide an interface between NAT oceanic and North American domestic airspace. The NAR System is designed to accommodate major airports in North America. These routes are subject to occasional changes and are re-published on a 56 day cycle.

Canadian DomesticTrack Systems

Within Canada there are three track systems: the Northern Control Area tracks (NCAs), the Southern Control Area tracks (SCAs) and the Northern Organized Track System (NOROTS); these provide links for NAT traffic operating between Europe and North America to central and western North American airports.

North Atlantic European Routing Scheme (NERS)

The NERS exists to provide an interface between NAT oceanic and European domestic airspace. The scheme is similar in concept to the NARS. It consists of a numbered series of predetermined routes, designed to accommodate eastbound traffic exiting the NAT en route to a number of major European airports. The NERS valid for a particular day will be published in the NAT track message but will only be published when the traffic density warrants their use. They are not expected to be published every day.

Shannon Oceanic Transition Area (SOTA) and Northern Oceanic Transition Area (NOTA)

Parts of the Shanwick OCA are designated as the Shannon Oceanic Transition Area (SOTA) and the Northern Oceanic Transition Area (NOTA). MNPS Airspace requirements are still applicable from FL285 to FL420 in both areas. NOTA and SOTA have the same vertical extent as the Shanwick OCA. Air Traffic Services are provided by Shannon ACC using the call sign SHANNON CONTROL.

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Brest Oceanic Transition Area (BOTA)

Part of the Shanwick OCA is designated as the Brest Oceanic Transition Area (BOTA). MNPS Airspace requirements are still applicable from FL285 to FL420. BOTA has the same vertical extent as the Shanwick OCA, and Air Traffic service is provided by the Brest ACC, callsign BREST CONTROL.

Communications

Due to the distances involved, the present primary method of communication is HF SSB voice. Long range VHF is available to aircraft when within 250 NM of land, and VHF is also used for the delivery of oceanic clearances to aircraft prior to entering the OCAs. There is also a VHF air-to-­air frequency (123.45 MHz) to allow an aircraft experiencing any communications or navigation problems to talk to another aircraft. All aircraft flying on NAT routes are also required to monitor 121.5 MHz. It is important that pilots appreciate that routine air/ground ATS Voice communications in the NAT Region are conducted via aeradio stations staffed by communicators who have no executive ATC authority. Messages are relayed by the ground station to/from the air traffic controllers in the relevant OAC.

HF

Long range HF communications is not user friendly. The correct choice of frequency is crucial and this is time-of-day dependent. Also the susceptibility of HF to atmospheric interference makes continuous listening to HF painful! In common with all aeronautical HF networks around the world, the NAT region utilizes ‘families’ of frequencies. This means that all or selected ground stations monitor the same frequency. The frequencies used are 3, 5, 8, 11 and 13 MHz. The general rule is that to talk to a station 1 000 NM away you will need a higher frequency during the day than at night (“the higher the Sun, the higher the frequency”). The propagation of HF across the Atlantic is well researched and the geophysical anomalies due to sunspots and magnetic interference are quite predictable so the ground station will generally dictate the choice of frequency. The first HF frequency to use with the air-ground station will be specified in the oceanic clearance. The ground radio operator will be monitoring all the frequencies in the ‘family’ so with the first call to the air-ground station the frequency being used is indicated by using the following phraseology:

“Shanwick Speedbird 289 on 88”

This would tell the ground operator that you are calling him on 8864 MHz. For the northerly routes, both Gander and Shanwick will monitor the day/night long range frequencies, and if there are propagation problems with Gander, the aircraft should still be able to relay through Shanwick. The two OACCs have landline data links (as they do with all the other OACCs in the NAT Region). At the point where control would be transferred from one OACC to the other, it is standard procedure to copy the initial position report to the new OACC to the previous one using the phraseology:

“Gander copy Shanwick this is Speedbird 289 position ... “

SATCOMVoice Communications

Since oceanic traffic typically communicate with ATC through aeradio facilities, a SATCOM call made due to unforeseen inability to communicate by other means should be made to such a facility rather than the ATC Centre, unless the urgency of the communication dictates otherwise.

SELCAL

When using HF communications and even when using ADS-C and/or CPDLC, pilots should maintain a listening watch on the assigned frequency, unless SELCAL is fitted, in which case they should ensure the following sequence of actions:

a)Provide the SELCAL code in the flight plan; (any subsequent change of aircraft for a flight will require passing the new SELCAL information to the OAC);

b)Check the operation of the SELCAL equipment, at or prior to entry into oceanic airspace, with the appropriate aeradio station. (This SELCAL check must be completed prior to commencing SELCAL watch); and

c)Maintain thereafter a SELCAL watch.

It is important to note that it is equally essential to comply with the foregoing SELCAL provisions even if SATCOM Voice or ADS/CPDLC are being used for routine air/ground ATS communications. This will ensure that ATC has a timely means of contacting the aircraft.

Position Reports

The system of ATC used across the NAT region is procedural ATC, which relies on pilot position reports to confirm the separation. As you have seen from the TM, the routes are organized to cross whole 5° of longitude at whole degrees of latitude. Likewise, whenever specified, north/ south routes cross whole 10° of latitude at whole degrees of longitude. At these points pilots are required to make position reports. For an east/west route this is going to be at approximately every 500 NM. This meets the ICAO requirement for position reports to be made at intervals not greater than 1 hour.

Standard air/ground message types and formats are used within the NAT Region and are published in State AIPs and Atlantic Orientation charts. To enable ground stations to process messages in the shortest possible time, pilots should observe the following rules:

a)Use the correct type of message applicable to the data transmitted;

b)State the message type in the contact call to the ground station or at the start of the message;

c)Adhere strictly to the sequence of information for the type of message;

d)All times in any of the messages should be expressed in hours and minutes UTC.

The message types are shown below with examples:

Position

Example: “Position, Swissair 100, on 8831, RESNO at 1235, Flight Level 330, Estimating 56 North 020 West at 1310, 56 North 030 West Next”

Request Clearance

Example: “Request Clearance, American 123, on 8831, 56 North 020 West at 1308, Flight Level 330, Estimating 56 North 030 West at 1340, 56 North 040 West Next. Request Flight Level 350”

or if a position report is not required

“Request Clearance, Speedbird 212 on 3476, Request Flight Level 370”

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