World Air Ops | NAT | Doc 007 MNPS Guidance

Guidance concerning Air Navigation in and above the NAT MNPSA CHAPTER 1010.2.7 The overall lateral navigation performance of all aircraft in the MNPS Airspace iscontinually assessed and compared to the standards established for the Region, to ensure that the TLS isbeing maintained.Monitoring of Gross Navigation Errors10.2.8 Radar stations capable of monitoring the boundaries of the NAT Region collect data onflights within MNPS Airspace, together with that on non-MNPS Airspace flights. The former data provides adirect input into the risk modelling of MNPS Airspace, whilst the latter provides a wider appreciation ofnavigation in the NAT Region and allows follow-up action to be taken on a larger sample of flights believedto have experienced navigation errors.10.2.9 The data collection process comprises two parts:a) continuous collection of all deviations of 25 NM or more (i.e. GNEs); andb) collection of data on deviations of between 15 and less than 25 NM as required.10.2.10 When a GNE or lateral deviation of less than 25NM has been detected by the ATS ProviderState or has been reported to ATC by the pilot, that ATS Provider unit will, in co-operation with theOperator, investigate its cause. It is important that all agencies react promptly to such reports of GNEs andother lateral deviations. Investigations should be made at once so that consideration can be given to the needfor swift remedial action. In order that deviation reports can receive prompt attention, each airline/Operatorshould nominate a person to be responsible for receiving reports and to initiate investigations; the name andfull address of this individual should be notified to each relevant ATS administration.10.3 Monitoring of Height-Keeping Performance10.3.1 The vertical navigation performance of operators within NAT MNPS Airspace is monitoredon a continual basis by the NAT CMA. Such monitoring includes both measurement of the technical heightkeepingaccuracy of RVSM approved aircraft and assessment of collision risk associated with all reportedoperational deviations from cleared levels.10.3.2 All identified operational situations or errors which lead to aircraft deviating from ATCcleared levels are subject to thorough investigation. Follow-up action after flight is taken with the operatorof the aircraft involved, to establish the reason for the deviation or cause of the error and to confirm theapproval of the flight to operate in NAT MNPS and RVSM Airspace. Operational errors, particularly thosein the vertical plane, can have a significant effect on risk in the system. For their safety and the safety ofother users, crews are reminded of the importance of co-operating with the reporting OAC in the compilationof appropriate documentation including the completion of an ‘Altitude Deviation Report Form’, as illustratedat Attachment 2.10.3.3 The detailed circumstances of all operational errors, both in the vertical and horizontalplanes, are thoroughly reviewed by the CMA, together with the Scrutiny Group of the NAT SPG, whichincludes current NAT pilots and controllers. Any lessons learned from this review, which may help to limitthe possibility of recurrences of such errors, are communicated back to NAT operators and ATS authorities.The intent is to improve standard operating procedures, thereby reducing the future frequency of operationalerrors and thus contribute to the safety of the overall system.10.3.4 At RVSM levels, moderate and severe turbulence may also increase the level of system riskand crews should report ALL occasions, whilst flying in MNPS Airspace, whenever a vertical deviation of300 ft or more occurs. The form at Attachment 2 may also be used for this purpose.NAT Doc 007 66 Edition 2010