ENR 7.8: North Atlantic (NAT) Safety Information

1.1 The early discovery of altitude deviations is extremely important to the overall safety of NAT operations. Deferring the required reports of leaving and reaching flight levels until the next routine communication may lead to instances where aircraft fly at the incorrect flight level for long durations. This is not acceptable from a system safety standpoint. While the actual number of vertical errors in the NAT Region is relatively small, some of these errors continue undetected (and therefore uncorrected) for long durations.

1.2 In practical terms:

1.2.1 Report leaving a flight level as soon as the aircraft begins climb or descent;

1.2.2 Report reaching a flight level as soon as the aircraft is level; and

1.2.3 In RVSM airspace, provide the reports even if air traffic control has not specifically requested them.

2.1 To help in assessing whether moderate or severe turbulence might have an impact on operations in the NAT Region when reduced vertical separation minimum of 1,000 feet is applied between FL290 and FL410 inclusive, the frequency and magnitude of altitude deviations from assigned FL caused by moderate to severe turbulence needs to be quantified.

2.2 To this end, air crews operating in the NAT Region, are required to include the magnitude of the deviation, in feet, from assigned FL in all required reports of moderate to severe turbulence.

3.1 General.

3.1.1 If so equipped, the pilot of an aircraft experiencing a two-way-radio communications failure must operate the secondary radar transponder on identity Mode A (Code 7600) and Mode C.

3.1.2 The pilot must also attempt to contact any ATC facility or another aircraft and inform them of the difficulty and request they relay information to the ATC facility with which communications are intended.

3.2 Communications failure prior to entering NAT oceanic airspace.

3.2.1 If operating with a received and acknowledged oceanic clearance, the pilot must enter oceanic airspace at the cleared oceanic entry point, level and speed and proceed in accordance with the received and acknowledged oceanic clearance. Any level or speed changes required to comply with the oceanic clearance must be completed within the vicinity of the oceanic entry point.

3.2.2 If operating without a received and acknowledged oceanic clearance, the pilot must enter oceanic airspace at the first oceanic entry point, level, and speed, as contained in the filed flight plan and proceed via the filed flight plan route to landfall. That first oceanic level and speed must be maintained to landfall.

3.3 Communications failure prior to exiting NAT oceanic airspace.

3.3.1 If cleared on flight plan route the pilot must proceed in accordance with the last received and acknowledged oceanic clearance to the last specified oceanic route point, normally landfall, then continue on the flight plan route. Maintain the last assigned oceanic level and speed to landfall. After passing the last specified oceanic route point, conform to the relevant State procedures/regulations.

3.3.2 If cleared on other than flight plan route the pilot must proceed in accordance with the last received and acknowledged oceanic clearance to the last specified oceanic route point, normally landfall. After passing this point, rejoin the filed flight plan route by proceeding directly to the next significant point ahead of the track of the aircraft as contained in the filed flight plan. Where possible use published ATS route structures, then continue on the flight plan route. Maintain the last assigned oceanic level and speed to the last specified oceanic route point. After passing this point conform to the relevant State procedures/regulations.

4.1 To ensure maximum use of available altitudes, aircraft entering RVSM airspace in the New York FIR should be prepared to advise ATC of the time or position the aircraft can accept the next higher altitude. WAH reports are also used to plan the altitude for aircraft; therefore, it is important that the altitude capability of the aircraft is known by controllers.

4.1.1 If the aircraft is capable of a higher altitude that is not preferred by the pilot, give the altitude in the WAH report and advise that you prefer not to be assigned that altitude.

4.2 ATC acknowledgment of a WAH report is NOT a clearance to change altitude.

4.3 The procedures will differ for eastbound and westbound aircraft since many of the eastbound aircraft will enter New York RVSM airspace from ATC sectors that have direct controller-pilot communications.

4.3.1 Eastbound aircraft entering RVSM airspace in the New York FIR:

4.3.1.1 Pilots may be requested by ATC to provide an estimate for when the flight can accept the next higher altitude(s). If requested, pilots should provide this information as soon as possible.

4.3.2 Westbound aircraft entering RVSM airspace in the New York FIR:

4.3.2.1 Pilots should include in the initial position report the time or location that the next higher altitude can be accepted.