World Air Ops | NAT | Doc 007 MNPS Guidance

Guidance concerning Air Navigation in and above the NAT MNPSA CHAPTER 88.2.8 All navigational information appearing on the Master Document must be checked against thebest available prime source data. When a re-route is necessary, some regulators recommended that a newMaster Document is prepared for the changed portion of the flight. In cases where the original MasterDocument is to be used, the old waypoints must be clearly crossed out and the new ones carefully entered intheir place. The checks listed in the previous paragraph must be carried out in respect of all new or revisedwaypoints.8.2.9 When ATC clearances or re-clearances are being obtained, headsets should be worn. Theinferior clarity of loud-speakers has, in the past, caused errors during receipt. Two qualified crew membersshould monitor such clearances; one of them recording the clearance on the Master Document as it isreceived, the other cross-checking the receipt and read-back. All waypoint co-ordinates should be read backin detail, adhering strictly to standard ICAO phraseology, except where approved local procedures make thisunnecessary. Detailed procedures pertaining to abbreviated clearances/read-backs are contained in theappropriate AIPs, and in this Manual at Chapter 5 - Oceanic ATC Clearances.Position Plotting8.2.10 A simple plotting chart provides a visual presentation of the intended route which, is definedotherwise only in terms of navigational co-ordinates. Plotting the intended route on such a chart may revealerrors and discrepancies in the navigational co-ordinates which can then be corrected immediately, beforethey reveal themselves in terms of a deviation from the ATC cleared route. As the flight progresses, plottingthe aircraft's present position on this chart will also serve the purpose of a navigation cross check, providedthat the scale and graticule are suitable.8.2.11 As the flight progresses in oceanic airspace, plotting the aircraft's position on this chart willhelp to confirm (when it falls precisely on track) that the flight is proceeding in accordance with itsclearance. However, if the plotted position is laterally offset, the flight may be deviating unintentionally, andthis possibility should be investigated at once.8.2.12 It is recommended that a chart with an appropriate scale be used for plotting. Many companyProgress Charts are of the wrong scale or too small. It has been noted that the use of plotting charts that aresmall can lead to oceanic errors. EAG Chart AT (H) 1; No 1 AIDU (MOD) Charts AT(H)1, 2, 3 & 4 and theJeppesen North/Mid Atlantic Plotting Charts are all useful compromises between scale and overall chart size;while the NOAA/FAA North Atlantic Route Chart has the advantage, for plotting purposes, of a 1°latitude/longitude graticule.Provision of Step-Climbs8.2.13 Tactical ATS Surveillance control and tactical procedural control are exercised in some areasof the NAT MNPS Airspace. However, oceanic clearances for most NAT flights are of a strategic nature,whereby flights are allocated a conflict-free route and profile from coast-out to landfall. Although suchstrategic clearances normally specify a single flight level for the entire crossing, there is often scope for enroute step-climb re-clearances as fuel burn-off makes higher levels more optimal. Controllers willaccommodate requests for step-climbs whenever possible. When so re-cleared, pilots should initiate theclimb without delay (unless their discretion was invited or unless a conditional clearance was issued) andalways report to ATC immediately upon leaving the old and on reaching the new cruising levels.Relief Crew Members8.2.14 Very long range operations may include the use of relief crew. In such cases it is necessaryto ensure that procedures are such that the continuity of the operation is not interrupted, particularly inrespect of the handling and treatment of the navigational information.NAT Doc 007 48 Edition 2010