World Air Ops | NAT | Doc 007 MNPS Guidance

Guidance concerning Air Navigation in and above the NAT MNPSA CHAPTER 6flight plans. Such aircraft should, however, enter oceanic airspace at the first oceanic entry point and speedcontained in the filed flight plan and proceed via the filed flight plan route to landfall.6.6.25 The rationale here must be appreciated. In such circumstances it is likely that ATC will havesimultaneously lost HF communications with multiple aircraft in the same vicinity. Should pilots thenwrongly apply the “normal” radio failure procedures and “fly the flight plan”, there is a possibility that twosuch aircraft may have filed conflicting flight paths/levels through the subsequent oceanic airspace, andwithout communications with either aircraft, ATC would then be unable to intervene to resolve the conflict.Since safe aircraft level separation assurance has already been incorporated into the current domesticclearances, it is consequently imperative that under such (Domestic and Oceanic) HF-blackoutcircumstances, all aircraft electing to continue flight into NAT oceanic airspace without a received andacknowledged oceanic clearance, should adhere to the flight level in the last received domesticclearance. No level changes should be made to comply with a filed oceanic level that is different fromthat of the domestic clearance in effect at the time that ATC air-ground communications were lost.Operational Procedures following Loss of HF Communications after Entering the NAT6.6.26 If the HF communications equipment failure occurs or HF Blackout conditions areencountered after entering the NAT then : -The pilot must proceed in accordance with the last received and acknowledged Oceanic Clearance,including level and speed, to the last specified oceanic route point (normally landfall). After passingthis point, the pilot should conform with the relevant AIP specified State procedures/regulations andif necessary rejoin the filed flight plan route by proceeding, via the published ATS route structurewhere possible, to the next significant point contained in the filed flight plan. Note: the relevantState procedures/regulations to be followed by an aircraft in order to rejoin its filed Flight Planroute are specified in detail in the appropriate State AIP.6.6.27 Aircraft with a destination within the NAT Region should proceed to their clearance limitand follow the ICAO standard procedure to commence descent from the appropriate designated navigationaid serving the destination aerodrome at, or as close as possible to, the expected approach time. Detailedprocedures are promulgated in relevant State AIPs.Summary of Operational Procedures Required following Loss of Air/Ground ATS Communications in theNAT Region6.6.28 The foregoing detailed operational procedures can be simply summarised as follows :• Equipment Failure before receiving an Oceanic Clearance:-Divert or fly the Flight Plan route, speed and initial planned oceanic level to landfall.• Blackout encountered (in an HF comms Domestic ATC environment) before receiving an OceanicClearance:-Continue at Domestic cleared level and follow flight planned route and speed to landfall.• Equipment Failure or Blackout after receiving an Oceanic Clearance:-Fly that clearance to landfall.In all cases, after landfall rejoin, or continue on, the flight planned route, using appropriate State AIPspecified procedures for the domestic airspace entered.NAT Doc 007 40 Edition 2010