The North Atlantic (NAT) region includes the Santa-Maria Oceanic FIR, Shanwick Oceanic FIR, Reykjavik FIR, Gander Oceanic FIR, Nuuk FIR, Bodø Oceanic FIR and New York Oceanic FIR north of 27°N. In general, each FIR has an associated Oceanic Control Area with base FL55 and no upper limit. Airspace at and above FL55 is Class A; otherwise it is Class G.
The airspace between FL285 and FL420 within the NAT region, excluding Nuuk FIR and the Shannon and Brest Oceanic Transition Areas, is defined as North Atlantic High Level Airspace (NAT-HLA). Operations within NAT-HLA are, in general, subject to the NAT Datalink Mandate (NAT DLM)1.
The A320 family are non-compliant with the NAT DLM, primarily due to lack of FANS-1/A2. Easyjet Operations within NAT-HLA are therefore only authorised on T9, T290 and “Blue Spruce” routes within the Reykjavik FIR where non-compliance with NAT DLM is countenanced due to the availability of alternative surveillance methods. Easyjet operations on T213, T13, T16 and “Blue Spruce” routes within the Shanwick FIR are permitted, but only at or below FL280.
In general, flight within NAT controlled airspace requires RVSM capability, RNP-10 capability3, 2 Long Range Navigation Systems (LRNS)4 and HF radio. Some designated routes, including many of those that easyJet is authorised to use, allow for alternative or reduced equipment. When operating in accordance with the MEL, if directed to “check MNPS capability” (e.g. you are operating with a single FMGC), check compliance for the specific route that you are intending to operate.
NAT DLM exemption is available as the airways are designated continental offshore rather than remote oceanic due to the availability of ground based surveillance. All flight levels are thus available to easyJet aircraft. Only 1 LRNS is required.
HF is required so the A319 cannot use these routes.
The airways are 20nm apart and operate as a pair, with T9 southbound only and T290 northbound only. Due to this arrangement, RNP2 and ADS-B are required for the NAT DLM exemption and SLOP is not authorised.
For southbound oceanic clearances, contact Shanwick Oceanic (127.65) 40 minutes before LASNO. If necessary, oceanic clearances may also be obtained from Shanwick Radio on one of the NAT-C HF frequencies or via a relay through London Control.
For northbound oceanic clearances, contact Shanwick on HF 40 minutes before ADVAT. The HF frequencies in use can be obtained from Lisbon Control.
Do not enter the Shanwick OCA without clearance.
When operating on these airways, 128.360 must be continuously monitored in addition to 121.5. This frequency is reserved for direct controller intervention and emergency purposes only; as normal, 121.5 should be used for broadcasting during in-flight contingencies and HF should be used for routine communications. Controllers will use the callsign “Shanwick Control” if calling on 128.360.
Maintain squawk for 10 minutes after passing LASNO or ADCAT, then squawk 2000.
Note that within the Shannon Oceanic Control Area (SOCA), which lies to the North of these routes, Shanwick delegates to Shannon control and domestic rules therefore apply.
These routes are all in NAT-HLA above FL285, so FL280 is maximum authorised. They are RNP10 routes and require HF, so they are not available to the A319. T13 is northbound only, T16 is southbound only, T213 is bi-directional.
LIDO sometimes erroneously selects T13 when returning to the UK from Madeira, and it is worth contacting Flight Planning to confirm as it is an extremely inefficient routing.
For southbound oceanic clearances, contact Shanwick Oceanic (127.65) 40 minutes before TAMEL or OMOKO. If necessary, oceanic clearances may also be obtained from Shanwick Radio on one of the NAT-C HF frequencies or via a relay through London Control.
Northbound, the most likely scenario is using T13 departing from Madeira. Oceanic clearance should be obtained from Santa Maria on HF, ideally 40 minutes before MANOX. Since MANOX is only around 220nm from Madeira, this means contacting Santa Maria early in the climb out, so it is worth confirming the relevant HF frequencies with Madeira while on the ground. For T213, obtain clearance from Shanwick on HF 40 minutes before BERUX; Lisbon Control will have the frequencies in use.
T13 and T16 are unusual for easyJet operations, in that they are the only two approved routes that involve crossing two OCAs that both use HF for primary communications. Expect to receive onward frequencies via HF around 10 minutes before the shared OCA boundary; request them if they are not forthcoming. A new oceanic clearance is not required, just a position report at the boundary; you can expect a new SELCAL check in response to this position report.
Squawk 2000 30 minutes after passing Oceanic Entry Point.
Do not enter the Shanwick OCA without clearance. Santa Maria OCA may be entered while waiting for a delayed clearance; maintain the flight level cleared by domestic until clearance is received.
Note that within the Shannon Oceanic Control Area (SOCA), which lies to the North of these routes, Shanwick delegates to Shannon control and domestic rules therefore apply.
BSR3 and BSR4 have a combined 97nm section between ASTIX and 61°N 12°34’W that is inside Shanwick OCA and thus inside the NAT-HLA when FL285 or above. Similarly, BSR5, BSR6, BSR7 and BSR8 have a combined 314nm section inside the Shanwick OCA. EasyJet aircraft are therefore restricted to FL280 and below when operating on these routes. Furthermore HF is mandatory, so they are not available to A319s. Only 1 LRNS is required.
Northbound, oceanic clearances are available from Shanwick Oceanic (127.65) and should be requested 40 minutes before ASTIX. Southbound clearances will be issued on the ground at Keflavik.
Do not enter Shanwick OCA without clearance.
Regarding squawk, I have found no specific rules, so the standard policy of squawking 2000 when 30 minutes past the oceanic entry point would seem to apply. For BSR3/4 this would mean that you would still be on a Scottish squawk at ASTIX.
These routes do not require HF and are exempt the NAT DLM, since ground based surveillance and VHF communications are available throughout the route. Thus all flight levels are available to all easyJet aircraft. Only 1 LRNS is required.
Northbound, oceanic clearances should be obtained from Iceland Radio (127.85/126.55) 20 minutes before entering Reykjavic OCA; authorisation to enter Reykjavik OCA can also be sought from Scottish ATC if necessary. OCA entry while awaiting a delayed clearance is acceptable. Southbound, oceanic clearances will be delivered on the ground by Keflavik.
Maintain squawk on entry to Reykjavic OCA.
Reykjavik centre operates a number of Direct Controller Pilot Communications (DCPC) VHF stations. The callsign “Reykjavik Control” indicates you are speaking to one. If you are speaking to “Iceland Radio”, you are speaking to a radio operator relaying messages in the normal Oceanic fashion.
Voice communication within the NAT region often utilises HF, which can be somewhat sub-optimal, and usually you are communicating with a radio operator who is relaying information to a controller, rather than directly with the controller. With the absence of direct ground based surveillance, the accuracy of these communications is even more critical than normal. For this reason, standard message formats are defined, which should be used whenever possible.
If using HF, include the frequency in use on initial contact, as HF radio operators will often be monitoring multiple frequencies.
An oceanic clearance request should include:
For example:
| Aircraft | “Shanwick Radio, Easy 123, Request Clearance on 8889” |
| ATC | “Easy 123, Shanwick Radio” |
| Aircraft | “Shanwick Radio, Easy 123, Estimating LASNO at 1230, request Mach .78, request Flight Level 360, able Flight Level 380” |
Coordinate with domestic ATC to be at the correct level and speed at the OCA entry point.
Reclearance will be required if it becomes apparent that the ETA to the OCA entry point is incorrect by more than 3 minutes.
Position reports should be made overhead waypoints and/or at significant points listed in the flight plan. The format of a position report is:
For example:
| Aircraft | “Shanwick Radio, Easy 123, Position on 8889” |
| ATC | “Easy 123, Shanwick Radio” |
| Aircraft | “Shanwick Radio, Easy 123, LASNO at 1230, Flight Level 360, estimating BEGAS 1303, next DEMOS” |
ATC must be notified if it becomes apparent that any passed ETA will be incorrect by more than 3 minutes.
For waypoints expressed as lat/long pairs, longitude minutes may be omitted for predominantly east-west flights and latitude minutes may be omitted for predominantly north-south flights.
Copy in ATC for adjacent OCAs when operating within 60nm of a common boundary (e.g. “SANTA MARIA copy SHANWICK, …”).
Revised estimate messages should be sent if it becomes apparent that a previously passed ETA will be incorrect by three minutes or more. The format is:
For example:
| Aircraft | “Shanwick Radio, Easy 123, Revised Estimate on 8889” |
| ATC | “Easy 123, Shanwick Radio” |
| Aircraft | “Shanwick Radio, Easy 123, estimating BEGAS 1308” |
Notify ATC and request clearance to deviate from track.
If ATC are not able to establish appropriate separation, they will advise the pilot of the conflicting traffic; responsibility for separation then rests with the pilot. In this case, or if ATC cannot be contacted:
Deviate away from the organised track system if possible. If the deviation is greater than 5nm, once the aircraft is approximately 5nm from track, change level according to the following table:
| Route centre line track | Direction | Change |
| 000° to 179° | Left | Descend 300ft |
| Right | Climb 300ft | |
| 180° to 359° | Left | Climb 300ft |
| Right | Descend 300ft | |
The acronym SAND can also be used: South of track then Ascend, North of track then Descend. Offset is always 300ft.
In the case where a clearance has been obtained to deviate a specific distance from track and it becomes necessary to deviate further, if a clearance to do so cannot be obtained, apply a 300ft deviation in accordance with the above table before deviating further.
Return to assigned flight level within 5nm of track when rejoining.
Whenever possible, obtain a revised clearance before initiating any action.
If this is not possible, leave the assigned track by turning at least 30° (left or right according to factors such as position relative to adjacent tracks, direction of alternate airport, SLOP being flown, terrain clearance etc.) to establish on a 5nm parallel offset track (from track centre line). Once established either:
Then proceed as required by the operational situation.
Turn on all exterior lights and keep nearby aircraft informed of position and intentions on 121.5 or 123.45.
If unable to initially maintain assigned flight level, minimise rate of descent when leaving original track.
Under no circumstances should a flight continue into oceanic airspace with unresolved navigation system errors.
Unrestricted operations within the NAT-HLA require two fully serviceable FMGCs, excepting those routes specifically promulgated as requiring only one. If an FMGC fails before the OCA boundary is reached, either divert, request reclearance via one of the single FMGC routes or request reclearance for a level below the NAT-HLA.
If an FMGC fails inside of Oceanic Airspace, consult with ATC as to the most suitable action. Generally, normal operations will continue, but all available methods to monitor the correct operation of the remaining system should be deployed.
If the second FMGC is lost or gives indications of degraded performance, inform ATC. If IRS data is available independent of the FMGCs, it can be used to manually plot positions on a chart. Positions should be plotted every 15 minutes, with suitable course adjustments being made. Maintaining visual contact with another aircraft may also be an option, and contacting other aircraft for wind data may be useful. If no instructions are received from ATC, consider climbing or descending 500ft.
Specific procedures are promulgated for communications failure inside Oceanic Airspace; do not use domestic procedures. Specifically, flight crews must not revert to their filed flight plans. This is partly because one of the reasons for loss of communications may be an HF blackout, in which case multiple aircraft may be affected.
As always with comms failures, squawk 7600 and use all available methods to reestablish communications. In Oceanic airspace, VHF relays from other aircraft (on 121.5 or 123.45) are particularly useful in the event of loss of HF. In HF blackout conditions, it is also worth trying alternative HF NAT frequencies as blackouts may only cover part of the spectrum, and NAT radio stations other than the one you are trying to contact may still be able to receive your transmissions.
If equipment failure occurs in domestic airspace prior to OCA entry when still in VHF contact with a domestic ATC unit, domestic diversion is strongly recommended. It is, however, permissible to continue into the OCA at the initial level and speed from the last acknowledged oceanic clearance, or, if such a clearance has not been received, in accordance with the initial level and speed from the filed flight plan. In either case, level and speed must be maintained until landfall.
If comms failure occurs prior to OCA entry due to HF blackout and no Oceanic clearance has been obtained, continue at the last flight level assigned by domestic ATC. This is because multiple aircraft are affected and they may have conflicting flight plans, whereas separation assurance has already been incorporated into the current domestic clearances. This level must be maintained until landfall.
In the event of comms failure inside the OCA, continue in accordance with the last received and acknowledged oceanic clearance to the last specified oceanic route point (normally landfall) and then revert to the domestic lost comms procedures of the relevant state.
If poor HF propagation conditions are encountered when inside the OCA, all flight crews should make regular broadcasts of their positions on 123.45.
When operating outside radar controlled airspace the accuracy of modern navigation systems serves to increase the probability of collision. Therefore, within Oceanic airspace it is encouraged to fly a track that is a parallel offset of the centreline of the cleared route. This track must only be offset to the right, and may be offset by 2nm or less. No ATC clearance or notification is required for this procedure.
Easyjet FMGCs can currently only be programmed with integer offsets, so are limited to a choice of centreline, 1nm right or 2nm right.
Overtaking aircraft should select an offset that will cause the least wake turbulence for the overtaken aircraft.
Any offset must be removed before the OCA exit point.
SLOP is not authorised on T9 or T290.
1As of January 2021, the activation of the NAT DLM is subject to a rolling delay, promulgated by NOTAM for each affected OCA. This is due to low traffic flow associated with the COVID pandemic. While this delayed activation continues, all levels are available to easyJet aircraft on all approved routes.
2The A320 family is fitted with FANS-B which uses the ATN rather than ACARS for datalink and is therefore incompatible with FANS-1/A.
3Strictly speaking, RNAV-10 capability (autonomous monitoring is not a requirement since only GNSS based LRNS has this ability), but the point is moot for easyJet aircraft.
4For A320 family, for LRNS read FMGC
5Descent below FL290 is particularly applicable if multiple parallel tracks will need to be crossed as it should avoid multiple TCAS RAs etc.